- Email: [email protected]
Apatite, SiO2, rutile and orthopyroxene precipitates in minerals of eclogite xenoliths from Yakutian kimberlites, Russia
Apatite, SiO2 , rutile and orthopyroxene precipitates in minerals of eclogite xenoliths from Yakutian kimberlites, Russia T.A. Alifirova, L.N. Pokhilenko, A.V. Korsakov PII: DOI: Reference:
S0024-4937(15)00028-6 doi: 10.1016/j.lithos.2015.01.020 LITHOS 3506
To appear in:
LITHOS
Received date: Accepted date:
29 May 2014 28 January 2015
Please cite this article as: Alifirova, T.A., Pokhilenko, L.N., Korsakov, A.V., Apatite, SiO2 , rutile and orthopyroxene precipitates in minerals of eclogite xenoliths from Yakutian kimberlites, Russia, LITHOS (2015), doi: 10.1016/j.lithos.2015.01.020
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Apatite, SiO2, rutile and orthopyroxene precipitates in minerals of eclogite xenoliths from
2
Yakutian kimberlites, Russia
3
Alifirova T.A.1,*, Pokhilenko L.N.1, Korsakov A.V.1
T
1
V.S. Sobolev Institute of Geology and Mineralogy of Siberian Branch of Russian Academy of
6
SC R
1
IP
4 5
1
Sciences, Novosibirsk, 630090, Russian Federation
NU
7
* Corresponding author: V.S. Sobolev Institute of Geology and Mineralogy of Siberian Branch of
9
Russian Academy of Sciences, Academician Koptyug ave. 3, Novosibirsk, 630090, Russian
10
MA
8
Federation. E-mail: [email protected]. Phone:7(383)330 80 68
D
11
Abstract
13
Eclogite mantle xenoliths from the central part of Siberian craton (Udachnaya and Zarnitsa
14
kimberlite pipes) as well as from the northeastern edge of the craton (Obnazhennaya kimberlite)
15
were studied in detail. Garnet and clinopyroxene show evident exsolution textures. Garnet
16
comprises rutile, ilmenite, apatite, and quartz/coesite oriented inclusions. Clinopyroxene contains
17
rutile (± ilmenite) and apatite precipitates. Granular inclusions of quartz in kyanite and garnet
18
usually retain features of their high-pressure origin. According to thermobarometric calculations,
19
studied eclogitic suite was equilibrated within lithospheric mantle at 3.2–4.9 GPa and 813–1080 °C.
20
The precursor composition of garnets from Udachnaya and Zarnitsa eclogites suggests their stability
21
at depths 210–260 km. Apatite precipitation in clinopyroxenes of Udachnaya and Zarnitsa allows us
22
to declare that original pyroxenes could have been indicative of their high P–T stability. Raman
23
spectroscopic study of quartz and coesite precipitates in garnet porphyroblasts confirms our
24
hypothesis on the origin of the exsolution textures during pressure-temperature decrease. With
AC
CE P
TE
12
ACCEPTED MANUSCRIPT
2
25
respect to mineralogical data, we suppose the rocks to be subjected to stepwise decompression and
26
cooling within mantle reservoir.
Keywords: exsolution, eclogite, grospydite, coesite, mantle xenoliths, Siberian craton
IP
28
T
27
SC R
29
1. Introduction
31
Considering all the deep-seated mantle xenoliths from kimberlite pipes worldwide, eclogites and
32
grospydites take a special place of mantle rock types. Although eclogitic rocks are one the main
33
sources of diamonds from kimberlite pipes (e.g. Reid et al., 1976; Sobolev, 1977; Taylor and
34
Anand, 2004), they are less abundant among the mantle rocks transported to the surface by
35
kimberlite melts. A number of works was devoted to the investigation of these rocks found in
36
Yakutian kimberlites (e.g. Sobolev et al., 1968; Spetsius, 2004), including coesite- and diamond-
37
bearing varieties.
CE P
TE
D
MA
NU
30
Mantle xenoliths with minerals comprising exsolution features represent valuable source of
39
information on the composition and stability of precursor phases and their transformation in
40
dependence on environmental conditions (temperature, pressure, and oxygen fugacity). In a light of
41
special interest to eclogitic rocks as potential hosts of diamonds, the exsolution textures have a
42
genetic significance. Among the population of eclogite xenoliths, the exsolution textures in garnet
43
and clinopyroxene are more or less common, being described in kimberlites of Yakutia, Russia
44
(Jerde et al., 1993; Taylor et al., 2003), South Africa (Harte and Gurney, 1975; Sautter and Harte,
45
1990; Schmickler et al., 2004), India (Patel et al., 2006), and other localities. Similar textures were
46
described in eclogitic bodies from metamorphosed complexes under ultra-high pressure (UHP)
47
conditions (e.g. Smith, 1988). Garnet lamellae in clinopyroxenes are likely to be the most abundant
48
exsolution textures found in eclogite mantle xenoliths (e.g. Jerde et al., 1993). This fact in turn
AC
38
ACCEPTED MANUSCRIPT
3
49
becomes a reason to suggest the exsolution phenomenon as a process responsible for the formation
50
of some upper-mantle derived eclogites (e.g. Smyth et al., 1984). Garnet from mantle and UHP metamorphic eclogites commonly contain oriented inclusions of
52
rutile and/or clinopyroxene considered as a result of exsolution from the precursor high-Ti or high-
53
Si garnet (Griffin et al., 1971) or formed by alternative ways (Hwang et al., 2007). In a few cases,
54
the oriented rutile needles are described in some garnet grains from a diamondiferous eclogite
55
xenolith (Korsakov et al., 2009). Apatite was found to be exsolved in garnet grains and rarely in
56
clinopyroxene porphyroblasts from eclogites of Sulu terrain, China (Ye et al., 2000), and West
57
Africa (Fung and Haggerty, 1995; Haggerty et al., 1994). Exsolution of SiO2 polymorphs in form of
58
quartz or coesite was observed in clinopyroxenes (e.g. Katayama et al., 2000) and garnets (Mposkos
59
and Kostopoulos, 2001; Ague and Eckert, 2012; Ruiz-Cruz and Sanz de Galdeano, 2013) of UHP
60
metamorphic eclogites and pelitic rocks. Alpha-quartz inclusions together with rutile were
61
described in garnets of sanidine-orthopyroxene eclogite xenolith from South Africa (Schmickler et
62
al., 2004). However, silica precipitates in minerals of eclogite mantle xenoliths were not considered
63
as exsolution products earlier.
CE P
TE
D
MA
NU
SC R
IP
T
51
This contribution is focused on a thorough mineralogical and petrographic examination of rare
65
eclogite mantle xenoliths with exsolution textures in garnet and clinopyroxene porphyroblasts
66
collected from Yakutian kimberlite pipes (Siberian platform, Russia). Major-element composition
67
data are used to constrain pressure-temperature conditions attending these rocks on various stages
68
of their transformation before the entrainment to the surface by kimberlitic melt.
AC
64
69 70
2. Geological setting
71
Mantle xenoliths with eclogitic paragenesis from two diamondiferous kimberlite pipes Udachnaya
72
and Zarnitsa were taken for this study. These two pipes are situated at Daldyn kimberlite field,
73
Daldyn-Alakit region of Yakutian kimberlite province on Siberian platform. The kimberlites
ACCEPTED MANUSCRIPT
4
intrusion was taken place in Devonian time according to U-Pb dating (Udachnaya 367±5 Ma, Kinny
75
et al., 1997; Zarnitsa 360±4 Ma, Davis et al., 1980). In geotectonic point of view, these kimberlites
76
are located within Markha granite-greenstone terrane near the suture with Daldyn granulite-gneiss
77
terrane of Siberian craton (Fig. 1) and include crustal and mantle materials as xenoliths. These
78
terranes were collided to each other at Paleoproterozoic time (2.6–2.2 Ga, Rosen et al., 2005)
79
forming a part of Anabar province (Fig. 1) (Rosen et al., 2005).
SC R
IP
T
74
The eclogite mantle xenolith from diamond-free Obnazhennaya pipe (Kuoika kimberlite field,
81
Lower Olenyok region; 148±3 Ma; Davis et al., 1980) is characterized for the comparison.
82
Tectonically the pipe is located within Birekte granite-greenstone terrane of Olenyok province (Fig.
83
1) (Rosen et al., 2005). At mid-Proterozoic time (2.3–1.9 Ga) Anabar province began the
84
amalgamation with Tungus and Olenyok provinces and at Neoproterozoic (1.9–1.8 Ga) all these
85
parts were accreted to terranes of Aldan province (Fig. 1), finally forming Siberian craton (Rosen et
86
al., 2005).
MA
D
TE
CE P
87
NU
80
3. Analytical techniques
89
The xenoliths listed in Table 1 were examined in polished sections with 30 μm thickness. The
90
petrographical examination and analytics were performed at V.S. Sobolev Institute of Geology and
91
Mineralogy, Siberian Branch of Russian Academy of Sciences (IGM), Novosibirsk, Russia.
92
Major-element compositions of minerals were determined by electron microprobe analysis using a
93
JEOL JXA-8100 electron microprobe at IGM. Analyses were conducted using an acceleration
94
voltage of 20 kV, a focused beam with a current of 10 nA, counting times of 20–30 s, and standard
95
PAP correction procedures (e.g. Lavrent’ev et al., 1987; Korolyuk et al., 2008). Precision and
96
accuracy were monitored using natural and synthetic standards that were measured at regular
97
intervals during each analytical session. Intra- and intergrain homogeneity within individual
98
samples was assessed by measuring 3–10 points in each grain. Detection limits are typically <0.04
AC
88
ACCEPTED MANUSCRIPT
5
wt% for SiO2, TiO2, Al2O3, MgO, CaO, Na2O, K2O, P2O5 and <0.05–0.07 wt% for FeO, MnO, and
100
Cr2O3.The Tescan scanning electron microscope was used to obtain back-scattered electron (BSE)
101
images and X-ray energy-dispersive system (EDS) for compositional data. Raman spectroscopic
102
study was performed on a Horiba Jobin Yvon LabRam HR800 confocal microspectrometer
103
equipped with an Olympus BX41 optical microscope. The spectroscopic technique was conducted
104
using 514 nm wavelength laser, grating 1800, hole 100 μm for the most of analyzed objects and 50
105
μm for inclusions smaller than 1 μm in thickness. The estimated spectral resolution is 0.5 cm–1. The
106
standard of pure silicon was used for the calibration.
NU
SC R
IP
T
99
Volume proportions of precipitates were estimated by following procedure. The host minerals in
108
thin sections were taken for the calculation. The areas of the interest were photographed in reflected
109
light and in back-scattered electrons to define minerals making up precipitates. Several shots from
110
optical microscope were taken to construct whole-grain composition. Analyzed areas were from 1.8
111
to 3 mm2 for the most of thin lamellae and about 30mm2 in case of coarse orthopyroxene lamellae
112
in eclogite OLK1514. The Plotcalc application (www.plotcalc.com) was used to obtain two-
113
dimensional proportions. Precipitates in garnet are composed of several minerals with different
114
morphology and commonly intergrown with each other. Thus, despite the high symmetry of garnet,
115
the volume proportions of lamellae might be underestimated, if assumed to be equal to surface ones.
116
Thus, to obtain volume proportions from the areal ones in garnet porphyroblasts, the correction
117
procedure was taken using the simplest reliable method (Kirkpatrick, 1977). The correction factor
118
was applied to the number of crystals to which the average surface squares were calculated. Surface
119
estimates of precipitates in clinopyroxene crystals are assumed to be equal to 3D proportions.
120
Calculated estimates for two to three host grains were averaged and shown in Table 2. The range of
121
volume proportions lies within 10% error for inclusions 3–5 μm wide and within about 20% for
122
smaller precipitates. The lowest range of volume estimates (<10%) are typical of coarse
123
orthopyroxene lamellae of eclogite OLK1514. To estimate chemical composition of precursor
AC
CE P
TE
D
MA
107
ACCEPTED MANUSCRIPT
6
minerals, the volume proportions of the host minerals and their lamellae were summarized after
125
conversion to mass percentage. The molar volumes of all chemical components were taken at
126
standard conditions to constrain chemical composition in weight percent.
T
124
IP
127
4. Xenolith petrography
129
On the basis of dominant primary mineralogy, the studied eclogites can be classified into four
130
groups: 1) quartz eclogites, 2) grospydite (kyanite eclogite with garnet of grossular composition), 3)
131
bimineralic eclogite and 4) orthopyroxene-bearing eclogite. Locality, rock type and mineral
132
assemblages of the samples are given in Table 1.
133
1) Quartz eclogites from Udachnaya (UV662/11 and UV58/10) are medium- to coarse-grained.
134
Garnets of saturated orange-red color compose subhedral porphyroblasts 3 to 7 mm in diameter.
135
Kelyphitic rims up to 0.2 mm in width are developed around garnets (Fig. 2). Clinopyroxenes
136
are dark green anhedral grains, varying from 2 to 10 mm in diameter. Secondary clinopyroxene-
137
feldspar symplectitic intergrowths are developed along the cracks and grain boundaries of
138
primary omphacitic clinopyroxenes, forming common “spongy” textures (Fig. 2). Straight grain
139
boundaries with typical triple junctions are well preserved in this group of eclogites. Quartz in
140
the eclogites is presented by irregular-shaped granular aggregates up to 4 mm in diameter with
141
separate grains of 0.5–1 mm in width (Fig. 2). Some of these aggregates contain needle-like
142
rutile inclusions. Coarse symplectitic intergrowths of quartz granular aggregates and garnet
143
were found in eclogite UV662/11. Areas with subrounded outlines up to 1–1.5 mm wide are
144
observed between primary minerals (Fig. 2A). They are composed of various secondary
145
products like oxides, sulfides, chlorite, amphibole, K-bearing minerals (feldspar, phlogopite),
146
carbonates, and spinels. Rare separate grains (<15 μm long) of apatite were found within these
147
pockets in the sample UV58/10.
AC
CE P
TE
D
MA
NU
SC R
128
ACCEPTED MANUSCRIPT
7
2) Grospydite xenolith from Udachnaya kimberlite (LUV134/10) shows complex fine- to medium-
149
grained texture. Kyanite grains up to 3 mm long are pale blue in color. They are mostly euhedral
150
and their simple {100} and/or {010} twinning is common. Garnet grains being from 0.5 to 2
151
mm in size have pale orange color. Two generations of garnet are observable. Older garnet-1 is
152
presented by subhedral to rounded individual grains. Younger garnet-2 is characterized by
153
elongated grains and shows vermicular morphology and is intergrown with quartz granular
154
aggregates, forming coarse symplectites up to 8-10 mm in width. Clinopyroxene grains are of
155
light green color with a light blue tint and up to 10 mm in diameter. They tend to be irregularly
156
shaped. Kyanite and garnet-1 grains are poikiloblastically included by the clinopyroxene
157
porphyroblasts. Despite the exceptional freshness of the sample, the primary clinopyroxene
158
(clinopyroxene-1) is nearly all penetrated by symplectites composed of spongy clinopyroxene-2
159
+ feldspar, with unreacted relics preserving in the symplectitic matrix. However, triple junctions
160
on grain boundaries are found between kyanite, garnet-1 and clinopyroxene-1 grains. Inclusions
161
of quartz are often found in kyanite grains. Pockets (usually <100 μm wide) with secondary
162
minerals (Ba-Sr-sulfates, sulfides, K-bearing minerals, oxides, amphibole) were also found in
163
this xenolith.
AC
CE P
TE
D
MA
NU
SC R
IP
T
148
164
3) Bimineralic eclogite from Zarnitsa kimberlite (LUV184/10) has fine- to medium-grained texture
165
with equigranular garnet and clinopyroxene porphyroblasts. Garnet grains are pale orange-red
166
colored and have a grain size ranging from 0.5–1 to 5 mm in diameter. Small garnet grains are
167
irregularly shaped, whereas larger ones tend to be euhedral. Pale green clinopyroxene of up to
168
3–4 mm long is patchy replaced by secondary alteration products (serpentine and chlorite).
169
Despite the abundant alteration, in some places the triple junctions between garnet and
170
clinopyroxene grains are preserved. Pockets with rounded outlines (up to 0.5 mm wide) filled
171
out by secondary minerals were also detected in the eclogite.
ACCEPTED MANUSCRIPT
8
4) Orthopyroxene-bearing eclogite from Obnazhennaya kimberlite (OLK1514) exhibits medium to
173
coarse grained texture alternating with the areas of lamellar texture. Pale orange-pink garnet
174
porphyroblasts are subhedral grains 3 to 5mm in diameter. Pale green anhedral clinopyroxene
175
porphyroblasts up to 8 mm long contain coarse orthopyroxene lamellae 30–100 μm wide and 1–
176
3 mm long. Grain boundaries between garnet and clinopyroxene are joined at 120° from place
177
to place. Individual grains of orthopyroxene are not typical of this sample. The eclogite is only
178
weakly altered, containing minor serpentine on grain boundaries contacting with kimberlite.
179
Primary assemblage minerals of studied eclogites include evident exsolution features considered in
180
detail separately.
MA
NU
SC R
IP
T
172
181
4.1. Exsolution textures
183
4.1.1. Garnet host
184
Coarse garnet porphyroblasts (up to 7 mm in diameter) from all studied xenoliths contain oriented
185
mineral inclusions considered as exsolution lamellae. Exsolved mineral assemblages for studied
186
samples are listed in Table 1. Precipitates are usually concentrated at the cores of large garnet
187
crystals and characterized by varying density of distribution in host garnets from sample to sample
188
(Table 2). Numerically garnets from Udachnaya and Zarnitsa xenoliths comprise 0.7–2.1 vol.% of
189
oriented inclusions, and garnet from Obnazhennaya sample holds about 1 vol.% of them.
AC
CE P
TE
D
182
190
It is commonly observed that oriented inclusions are more or less uniformly distributed within
191
host garnets (Fig. 3 A–B). However, a large inclusion of phlogopite in garnet of Zarnitsa xenolith
192
was found to be surrounded by a halo of smaller faceted inclusions of quartz and apatite look like
193
the same as precipitates in garnet of this sample (Fig. 3 C–D). The typical feature of garnet
194
exsolution textures is to contain both monomineralic and polymineralic (or intergrown) lamellae.
195
Close up photos of several examples are shown in figure 4.
ACCEPTED MANUSCRIPT
9
Garnet porphyroblasts contain lamellae of rutile, quartz (and coesite), apatite, and ilmenite.
197
Light brown to yellowish in color rutile usually forms elongated needles or prisms 1–5 μm in
198
diameter and 10–200 μm long. It rarely has a bluish tint due to a strong interference color. Lamellae
199
of quartz, coesite and apatite are colorless. Quartz lamellae in garnet typically have more isometric
200
morphology, up to 5 μm in width and 30 μm in length, nevertheless long prisms of quartz were also
201
found (Fig. 4A). Coesite lamellae in garnet visually have no difference with quartz ones (Fig. 4B),
202
but coesite exsolutions are slightly smaller in size – no more than 20 μm long and 2-3 μm wide.
203
Apatite precipitates are characterized by prismatic morphology, up to 5 μm in width and 50 μm long
204
(Fig. 4 C–D). They differ from other colorless precipitates by a lower optical contrast. Ilmenite
205
forms no individual lamellae in garnets of studied samples, presenting only in intergrowths with
206
rutile precipitates. Most quartz and apatite precipitates are surrounded by tiny black or colorless
207
dots less than 1 μm in size, which likely represent the residues of decrepitated fluid inclusions.
TE
D
MA
NU
SC R
IP
T
196
CE P
208
4.1.2. Clinopyroxene host
210
Clinopyroxene occurs in form of large unaltered grains (up to 8mm long) or relics mounted into
211
pyroxene-feldspar symplectites. Both of them contain exsolution lamellae. Minerals exsolved from
212
clinopyroxene grains include rutile, apatite, ilmenite and orthopyroxene (only in Obnazhennaya
213
sample) (Fig. 5). They form: (i) thin elongated needles or plates from 0.5 to 10 μm wide and 50–
214
200 μm long; (ii) spindly oriented inclusions about 30–50 μm long and 3–10 μm thick; (iii)
215
thickened near-tabular plates up to 100 μm thick and several hundred microns long. The first type is
216
common for all the minerals composing lamellae in the clinopyroxenes, whereas the third one
217
corresponds only to the orthopyroxene lamellae in clinopyroxene of Obnazhennaya sample
218
(OLK1514). Udachnaya and Zarnitsa eclogitic clinopyroxenes generally contain about 0.9–1.9
219
vol.% of exsolution lamellae; clinopyroxene from the Obnazhennayaxenolith comprises almost 12
220
vol.% of exsolved minerals (Table 2).
AC
209
ACCEPTED MANUSCRIPT
10
Rutile lamellae forming needles, prisms or spindle-shaped grains up to 10 μm wide and 200 μm
222
long are brown in color, usually with a purple or green interference tint (Fig. 5A). Some of them
223
found in spongy-textured symplectites after clinopyroxene are with resorbed edges and surrounded
224
by ilmenite. Apatite exsolutions are presented as thin elongated needles (<1 μm wide and 10–25 μm
225
long) or plates (3–5 μm wide and up to 10 μm long) (Fig. 5 C–D). They form both individual and
226
intergrown lamellae. Ilmenite in clinopyroxenes has a minor distribution compared to other
227
exsolved minerals. It was identified only together with abundant rutile lamellae. Orthopyroxene
228
lamellae show morphologically various forms from small prism-like inclusions (2–5 μm wide and
229
20–50 μm long) to coarse well-defined extended plates up to 100 μm wide and several hundred
230
microns long (Fig. 5B). Orthopyroxene lamellae are usually intergrown with rutile ones.
MA
NU
SC R
IP
T
221
D
231
4.1.3. Kyanite host
233
Grospydite xenolith LUV134/10 contains kyanite crystals with rutile oriented inclusions occupying
234
about 0.2–0.4 % by volume. Rutile forms elongated needles with 2–4 μm thick and up to 200 μm
235
long (Fig. 6A).
CE P
AC
236
TE
232
237
4.2. Granular mineral inclusions
238
Contrary to UHP metamorphic rocks, which contain abundant single and multiphase mineral
239
inclusions, the rock-forming minerals are almost inclusions free, but in some case contain
240
inclusions of each other, testifying for their contemporary crystallization. Rounded and/or subhedral
241
granular SiO2 inclusions are more often included into garnet and kyanite grains in samples
242
LUV134/10 and UV58/10 from Udachnaya kimberlite. Being partially or slightly exposed, they
243
seem to be monocrystalline quartz with no evident palisade texture or polycrystalline shell. Larger
244
ones are frequently surrounded by medium to distinct radial crack patterns (Fig. 6B), whereas
245
smaller subhedral inclusions when unexposed demonstrate an obvious birefringent halo (Fig. 6C).
ACCEPTED MANUSCRIPT
11
246
4.3. Symplectite intergrowths
248
Xenoliths from Udachnaya kimberlite pipe include two types of symplectite (Table 1): 1) type I
249
represents subgraphic intergrowths of vermicular garnet and granular quartz aggregates with clear
250
outlines and whole size up to 10 mm (Fig. 7A); 2) type II looks like irregular aggregates composed
251
of feldspar and less sodic clinopyroxene (Cpx-2) (Fig. 7B), they are without abrupt margins, and a
252
grain size of composing minerals varies from the first microns to about 100 μm.
NU
SC R
IP
T
247
Coarse type I quartz-garnet symplectite was found in two Udachnaya xenoliths (UV662/11 and
254
LUV134/10). Type II feldspar-pyroxene symplectite replaces a part (samples UV662/11 and
255
UV58/10) or nearly all the clinopyroxene (sample LUV134/10). Feldspar from type II symplectite
256
belongs to plagioclase in xenoliths UV662/11 and LUV134/10, and to K-feldspar in UV58/10
257
eclogite. Both types of symplectite occur in quartz eclogites (Table 1).
TE
D
MA
253
CE P
258
5. Results
260
5.1. Major-element chemistry
261
5.1.1. Garnet composition
262
Garnets from studied xenoliths exhibit various composition range in Prp-Alm-Grs system (Fig. 8).
263
The end-member calculations were from Locock (2008). Two of studied xenoliths from Udachnaya
264
(LUV134/10 and UV662/11) contain pyrope-poor garnets (Prp<30) with Prp 13–19Alm24–41Grs35–59.
265
With respect to classification of Coleman et al. (1965), a pair of samples from Udachnaya and
266
Zarnitsa belongs to group B eclogites (UV58/10 and LUV184/10 respectively) having Prp31–
267
44Alm41–44Grs8–21,
268
eclogite (OLK1514) (Table 1). A wide range of garnet compositions is typical of mantle eclogites
269
worldwide (e.g. Aulbach et al., 2007; Caporuscio and Smyth, 1990; Hills and Haggerty, 1989;
270
Shervais et al., 1988; Sobolev, 1977; Taylor et al., 2003).
AC
259
and a single sample from Obnazhennaya with Prp62–63Alm25–26Grs6–7 is group A
ACCEPTED MANUSCRIPT
12
Individual garnet porphyroblasts are nearly homogeneous in their main components (Table 3);
272
the composition slightly varies in minor elements like Na, Ti, and P. In garnet composition the
273
interdependence between Na2O and TiO2+P2O5 and between Mg# {=100×Mg/(Mg+Fetotal)} and
274
TiO2+P2O5 was traced (Fig. 9). It sorts with the data from Koidu eclogitic garnets and from garnets
275
of other localities worldwide (Fung and Haggerty, 1995). The positive correlation between Na and
276
Ti (and P) contents in the garnets was also found in eclogites from Mir kimberlite (Yakutia, Russia)
277
(Beard et al., 1996). An excess Na content relative to Ti is considered to result from a substitution
278
of sixfold coordinated cations by Si (Beard et al., 1996), what was firstly supposed by Sobolev and
279
Lavrent'ev (1971).
MA
NU
SC R
IP
T
271
Eclogitic garnets containing apatite + rutile exsolution lamellae from Koidu kimberlite (Sierra
281
Leone; Fung and Haggerty, 1995) and Yangkou (Sulu terrane, China; Ye et al., 2000) have major-
282
element compositions akin to those for garnets with the same exsolution assemblage of this study
283
(Figs. 8 and 9). Composition of garnet containing rutile lamellae and quartz inclusions from
284
diamondiferous eclogite (Mir kimberlite pipe, Yakutia; Korsakov et al., 2009) resembles that of
285
studied grospydite xenolith LUV134/10 from Udachnaya. The composition of garnet with quartz
286
and rutile inclusions from sanidine-orthopyroxene eclogite of Zero kimberlite (South Africa;
287
Schmickler et al., 2004) is markedly close to that of garnet from studied Obnazhennaya
288
orthopyroxene-bearing eclogite OLK1514.
AC
CE P
TE
D
280
289
UHP crustal garnets including apatite precipitates like those from Kimi area, Rhodope, Greece
290
(Mposkos and Kostopoulos, 2001), from Ceuta, Northern Rif, Spain (Ruiz-Cruz and Sanz de
291
Galdeano 2013), Western New England, USA (Snoeyenbos and Koziol, 2008) and Australian
292
Bingara-Copeton alluvial garnets (Barron et al., 2005; not plotted on Fig. 8) have compositions
293
different from those in studied samples being richer in almandine and spessartine components (Fig.
294
8).
ACCEPTED MANUSCRIPT
13
Garnets from Udachnaya eclogites have higher TiO2 and Na2O (0.10–0.31 and 0.06–0.10 wt %,
296
respectively) contents as opposed to eclogites of Zarnitsa and Obnazhennaya, where TiO2 and Na2O
297
are 0.02–0.10 and 0.02–0.04 wt %, respectively. Low Na2O contents in garnet of OLK1514
298
correspond to data of Taylor et al. (2003) considering them as a typical feature of eclogites and
299
websterites from diamond-free Obnazhennaya kimberlite pipe. Na2O contents in garnets of studied
300
Udachnaya eclogite xenoliths fall into the range of those in the diamondiferous eclogites from the
301
same pipe (0.05–0.24 wt %; Sobolev and Lavrent’ev, 1971; Sobolev et al., 1994).
NU
SC R
IP
T
295
Using calculation scheme for garnet composition of Locock (2008), garnets from group C
303
eclogites UV662/11 and LUV134/10 contain up to 3 mol. % of majorite component (Table 3),
304
while Si contents lower 3.03 are considered as uncertainties within microprobe analyses.
MA
302
D
305
5.1.2. Clinopyroxene composition
307
Clinopyroxene compositions cover a wide range between omphacite and diopside (Fig. 10). On the
308
diagram of Essene and Fyfe (1967), they correspond to omphacite in Udachnaya xenoliths (Aug43–
309
67Jd31–53Aeg0–4)
310
11)
311
CaEs. The end-member calculations were from Katayama et al. (2000). Individual grains are
312
slightly inhomogeneous in major-element contents, especially in MgO and Al2O3 (Table 4). Using
313
scheme of Taylor and Neal (1989), clinopyroxene compositions of the sample UV58/10 lie in a
314
field of group C eclogites, and those of the UV662/11 belong to group B eclogites (Fig. 11). Garnet
315
compositions of these two samples demonstrate an inverse pertaining (Fig. 8).
CE P
TE
306
and to sodium-rich diopside-augites in samples from Zarnitsa (Aug72Jd15–16Aeg10–
AC
and Obnazhennaya (Aug73–75Jd21–22Aeg3–4) (Fig. 10), where Aug = Di + Hd + En + Fs + CaTs +
316
Composition of the clinopyroxenes containing apatite lamellae differs from that of eclogitic
317
clinopyroxene with the same lamellae from Koidu kimberlite (Fung and Haggerty, 1995) as shown
318
on figures 10 and 11. Clinopyroxene of the primary assemblage (cpx-1) in grospydite LUV134/10
319
exhibits concentrations of Ca-Eskola component as high as 6 mol. % opposed to other
ACCEPTED MANUSCRIPT
14
320
clinopyroxenes containing no Ca-Eskola molecule (Table 4). Primary clinopyroxenes of all studied
321
xenoliths contain Ca-Tschermak molecule, but the content ranges from 1 to 8 mol. % (Table 4). Secondary symplectitic clinopyroxenes have sodium-rich augitic composition with Aug77–93Jd2–
T
322 323
20Aeg0–4
324
mol.%) content compared to clinopyroxenes of primary assemblage (CaTs< 8 mol.%).
SC R
IP
(Table 4). A distinctive feature of these pyroxenes is relatively high Ca-Tschermak (10–16
325
6.1.3. Orthopyroxene composition
327
Orthopyroxene lamellae observed in clinopyroxene of OLK1514 have En85Fs14 and minor other
328
components (CaTs about 1 mol.%). Orthopyroxene contains about 0.7 wt % of Al2O3 and 0.22 wt
329
% of CaO (Table 4). The contents of CaO and Al2O3 are lower than those in orthopyroxenes from
330
group A eclogites from Obnazhennaya (Taylor et al., 2003) and comparable with orthopyroxene
331
compositions from Obnazhennaya websterite and clinopyroxenite xenoliths (Alifirova et al., 2012;
332
Taylor et al., 2003).
MA
D
TE
CE P
333
NU
326
6.1.4. Kyanite composition
335
Kyanite composition is characterized by SiO2 and Al2O3 contents 61.6 and 37.2 wt %, respectively.
336
Among the minor elements, Fe and Ti are found (FeOtotal about 0.3 wt % and TiO2 up to 0.06 wt
337
%), other elements are below the detection limit. Al2O3/SiO2 ratio is slightly lower than an ideal one
338
(1.65 versus 1.7). It is supposed to be reasonable (Pearson and Shaw, 1960) if the substitution of
339
small amounts of Fe, Ti, Mg and trace elements for Al is allowed.
AC
334
340 341
6.1.5. Rutile composition
342
Rutile composition has minor variations from sample to sample and among the different
343
morphologies (precipitates in garnet and clinopyroxene or individual grains). TiO2 ranges from 98.1
344
to 99.7wt % with slight amounts of FeO (0.29–0.67 wt %), CaO (up to 0.33 wt %) and Al2O3 (up
ACCEPTED MANUSCRIPT
15
0.23 wt %). Rutile lamellae in garnets from grospydite LUV134/10 contain ZrO2 as high as 0.20 wt
346
%, what is comparable with ZrO2 contents in rutiles from diamond inclusions (0.03–0.19 wt %;
347
Sobolev and Yefimova, 2000). Rutile composition is close to that in diamond-bearing eclogite from
348
Koidu kimberlite (Hills and Haggerty, 1989). Concentrations of Mg, Cr, and Nb oxides are below
349
the detection limit.
SC R
IP
T
345
350
6.1.6. Ilmenite composition
352
Ilmenite from studied Udachnaya and Zarnitsa eclogites is almost uniform in composition within
353
individual rock either in form of lamellae or separate grains and rims around rutile grains. It has
354
TiO2 52.00–56.10 wt % and FeO 39.35–44.62 wt %. Content of MgO is relatively low (<3.60 wt
355
%). Ilmenites contain MnO from 0.58 to 3.25 wt % and CaO no more than 0.73 wt %. According to
356
formula calculation, the ilmenites contain all iron in divalent form with no Fe3+. Compositions of
357
ilmenites lie into “non-kimberlitic” field according to Wyatt et al. (2004). However, statistically
358
kimberlitic ilmenites may also fall into this field (Wyatt et al., 2004).
MA
D
TE
CE P
359
NU
351
6.1.7. Feldspar composition
361
Feldspars composing in type II symplectites cover a range of anorthite-albite-orthoclase contents.
362
Plagioclase with An45–53Ab46–55 is observed in symplectites of xenoliths UV662/11 and
363
LUV134/10. Alkali feldspar with Or98Ab2 (orthoclase or sanidine) composes symplectites after
364
omphacitic clinopyroxene in sample UV58/10.
AC
360
365 366
5.2. Raman analyses
367
5.2.1. Oriented inclusions
368
All of studied samples except for grospydite LUV134/10 contain garnets with oriented quartz
369
inclusions (precipitates). Raman spectra of the precipitates demonstrate frequency shifts of normal
ACCEPTED MANUSCRIPT
16
α-quartz peaks; it is more obvious when the strongest quartz mode of 464 cm–1 is considered. The
371
highest shifts up to 476 cm–1 were fixed in small unexposed individual lamellae of quartz in garnets
372
of UV662/11 and UV58/10 (Fig. 12A). Slightly lower shifts up to 471 cm–1 were measured in the
373
same type of lamellae in the sample from OLK1514 (Obnazhennaya). The shift to no more than 466
374
cm–1 was obtained for quartz lamellae in garnets of Zarnitsa sample LUV184/10. For all the
375
samples, the following features were observed: 1) Raman shift is higher for smaller inclusions of
376
several microns wide; 2) exposed lamellae demonstrate lower values of the main quartz band shift;
377
3) discrete quartz lamellae have shifts higher than those in complex (intergrown with rutile or
378
apatite) ones; 4) inclusions surrounded by cracks have the lowest or no shifts of quartz bands.
MA
NU
SC R
IP
T
370
Coesite precipitates in garnet of UV662/11 were identified using Raman technique (Fig. 12B).
380
A typical coesite band of 521 cm–1 is shifted to 525 cm–1. At the other samples the coesite was not
381
found yet.
TE
D
379
Raman analysis was helpful in identification of minerals composing small colorless precipitates
383
in garnet and clinopyroxene hosts, especially in the case when they are not exposed. Apatite
384
lamellae were found in garnets of four samples from Udachnaya and Zarnitsa kimberlite pipes, and
385
in clinopyroxenes of three samples (UV662/11, UV134/10 and LUV184/10). Apatite spectra both in
386
garnet and clinopyroxene hosts demonstrate normal bands on 960–964 cm–1. According to EDS
387
data, apatites are likely to contain F together with minor Cl, S and OH–.
AC
CE P
382
388 389
5.2.2. Quartz granular inclusions and aggregates
390
Quartz inclusions in garnet and kyanite from two samples LUV134/10 and UV58/10 were studied.
391
Raman spectroscopic study reveals a common quartz band of 464 cm–1 for partially or slightly
392
exposed SiO2 inclusions in kyanite, and up to 466 cm–1 for them in garnet. Whereas an obvious
393
frequency shift of quartz band to 469 cm–1 in small uncovered SiO2 inclusions is observed.
394
Inclusions with crack patterns and large inclusions have lower or no frequency shifts, and those
ACCEPTED MANUSCRIPT
17
with birefringent halo demonstrate higher values for the common quartz band shift. Quartz grains
396
from type I symplectite and granular aggregate show a clear 464 cm–1 mode without any frequency
397
shift.
T
395
IP
398
5.3. Geothermobarometry
400
During several decades, the geothermobarometry for the rocks with eclogitic paragenesis remains as
401
a complex challenge. There is no universal way for the pressure-temperature calculation suitable for
402
all the known types of eclogites. In this paper we use different approaches for the P–T estimation
403
with respect to the type of each studied eclogite.
MA
NU
SC R
399
Temperature estimates for studied eclogite xenoliths were performed using garnet-
405
clinopyroxene Mg-Fe exchange reaction geothermometry of several calibrations (Ai, 1994; Ellis
406
and Green, 1979; Krogh, 1988; Krogh Ravna, 2000) (Fig. 13). To apply Fe–Mg exchange
407
geothermometry, the calculation of Fe3+ was assumed to be equal Na excess over Al + Cr for
408
clinopyroxenes. The ratios of Fe3+/Fetotal in studied garnets are low (0.04–0.06) according to charge
409
balance. The next step was to find the pressure on a geotherm that corresponds to the calculated
410
temperature (Table 5). The geotherm with a heat flow of 40 mW/m2 was taken, because of the best
411
suitability to the geothermal gradient of the lithospheric mantle under Udachnaya kimberlite pipe
412
(Boyd et al., 1997). Then, the average of estimated P–T parameters was counted. For the calculation
413
of average temperatures, the data obtained with the equation of Ai (1994) were excluded from the
414
computation due to their overstating. The average P–T values are represented in Table 5. According
415
to the calculations, studied eclogites from Udachnaya and Zarnitsa kimberlite pipes were
416
equilibrated at T=970–1080 °C and P=4.1–4.9 GPa. Obnazhennaya eclogite is likely to be
417
equilibrated at T=813 °C and P=3.2 GPa.
AC
CE P
TE
D
404
418
The eclogite xenolith from Obnazhennaya kimberlite pipe contains both orthorhombic and
419
monoclinic pyroxenes. Additionally, for this sample a Ca-in-orthopyroxene geothermometer in pair
ACCEPTED MANUSCRIPT
18
420
with garnet-orthopyroxene geobarometer was used (Brey and Kohler, 1990). Obtained P–T
421
estimates of 813 °C and 3.0 GPa are remarkably close to those computed by the former way. For the comparison with obtained data, the net transfer reactions geobarometry results according
423
to equations of Krogh Ravna and Terry (2004) were also shown on P–T plot (Fig. 13). Strictly
424
following to recommendations of Krogh Ravna and Terry (2004), it is better to use the equations for
425
the rocks with the full or minimally permissible mineral assemblage; otherwise the errors will be
426
great. Grospydite xenolith LUV134/10 from Udachnaya pipe fits to minimal criteria for the
427
evaluation. Using the geobarometer (equation 1 from the work of Krogh Ravna and Terry, 2004) in
428
combination with exchange thermometers discussed before the P–T parameters were calculated.
429
The average of them is comparable with that yielded by the firstly described method (Table 5).
MA
NU
SC R
IP
T
422
Transformation of the eclogites recorded in a presence of symplectites and exsolution textures
431
reveals the change of pressure and temperature parameters in the history of studied rocks. To
432
evaluate pressures of the type II symplectites formation, the clinopyroxene-feldspar geobarometer
433
was used (Holland, 1980). The geothermometer of Krogh Ravna (2000) was taken for the
434
combination. According to the calculations the type II symplectites were formed at 810–880 °C and
435
2.0–2.1 GPa in the quartz stability field. However, it should be noted, that symplectitic
436
clinopyroxenes are not in equilibrium with the garnet what is required when using classical
437
geothermometers.
AC
CE P
TE
D
430
438
Using the terminology of Joanny et al. (1991), studied type II feldspar-clinopyroxene
439
symplectites were preserved on globularization stage. The drop of pressure is responsible for the
440
globularization occurrence. Thus, the lamellar width is no more representative of temperature;
441
dependence on temperature according to the growth law during discontinuous precipitation is not
442
applicable (Joanny et al., 1991). However, we may estimate pressure at which type II symplectites
443
were stable. The jadeite contents ≤ 20 mol. % in secondary clinopyroxenes are attributed to those
444
less than 2.0 GPa (Gasparik and Lindsley, 1980). Symplectitic pyroxenes contain higher Ca-
ACCEPTED MANUSCRIPT
19
Tschermak content (>10 mol. %) compared to primary clinopyroxenes (CaTs < 8 mol. %).
446
According to the data for CMAS system (Gasparik, 2000) secondary pyroxenes should be stable at
447
pressures about 1.7–1.9 GPa at temperatures <1000 °C. It is more or less consistent with
448
thermobarometric results described before. Alternatively, pressures and temperatures were
449
estimated by applying clinopyroxene-2 compositions to the NCMAS dataset (Gasparik, 2014). The
450
contents of Ca, Al and Na in clinopyroxenes from type II symplectites suggest the temperatures and
451
pressures of about 1050–1070 °C and 2.6–3.0 GPa for the quartz eclogites from Udachnaya
452
(UV662/11 and UV58/10), and <800 °C and 1.6 GPa for the grospydite LUV134/10. Application of
453
data for NCMAS system (Gasparik, 2014) assumes slightly higher pressures and temperatures of
454
the type II symplectites formation, especially in quartz eclogites from Udachnaya.
MA
NU
SC R
IP
T
445
D
455
6. Discussion
457
6.1. Evolution of eclogite mantle xenoliths and constraints on their P–T history
CE P
TE
456
Mantle xenoliths in kimberlites worldwide are commonly presented by peridotites with fewer
459
amounts of other rock varieties including pyroxenites and eclogites (e.g. Dawson, 1980; Nixon and
460
Boyd, 1973). Nevertheless, several kimberlites contain eclogite nodules prevailing over other ones:
461
Zagadochnaya (Yakutia, Russia; Bobrievich et al., 1964; Sobolev et al., 1968); Roberts Victor and
462
Bobbejaan (South Africa; MacGregor and Carter, 1970; Smyth et al., 1984); Orapa (Botswana;
463
Shee and Gurney, 1979); Koidu (Sierra Leone; Hills and Haggerty, 1989). Taking into account the
464
common genetic links between mantle eclogites and diamonds, there is no doubt the significance of
465
a diversified examination of eclogites from different localities.
AC
458
466
The origin of the mantle eclogites is controversial (e.g. Jacob, 2004; Griffin and O’Reilly,
467
2007), with no exception for Yakutian ones (Sobolev et al., 1994; Snyder et al., 1997; Taylor et al.,
468
2003). The debates focused around two end-member hypotheses describing eclogite mantle
469
xenoliths as relics of subducted oceanic crust (“crustal” hypothesis; e.g. MacGregor and Manton,
ACCEPTED MANUSCRIPT
20
1986; Ireland et al., 1994; Jacob et al., 1994) or as products of high-pressure crystallization from
471
magmas with a purely mantle source (“mantle” hypothesis; e.g. Smyth et al., 1989; Caporuscio and
472
Smyth, 1990). In this contribution we lack stable isotope and trace element data in order to argue
473
the origin of eclogite xenoliths in Yakutian kimberlites either from crustal or mantle material.
474
However, several aspects regarding the origination and subsequent evolution of considered eclogitic
475
suite should be mentioned.
SC R
IP
T
470
Garnet grains of Udachnaya and Zarnitsa eclogites contain about 0.1 vol.% of apatite
477
precipitates, what corresponds to 0.09–0.12 wt % of P2O5 in recalculated garnet compositions and
478
to 0.06–0.07 wt % of P2O5 in whole-rock compositions. The value is comparable with an average
479
P2O5 content in the upper mantle (0.03–0.05 wt %) as estimated by Baker and Wyllie (1992) and is
480
lower than in N-MORB (0.17 wt %) (Sun and McDonough, 1989). To cover an entire budget of
481
P2O5 content in MORB, a free apatite is required in the rocks. However, apatite crystals are found to
482
be extremely rare in studied eclogites. Following the observations of Haggerty et al. (1994) and
483
experimental results of Watson (1980) the low whole-rock P2O5 contents in studied eclogites might
484
be explained by: 1) low P2O5 content in the eclogite protolith or source melt composition like
485
komatiites (about 0.08 wt % of P2O5) or melts formed in equilibrium with peridotite; 2)
486
redistribution of the phosphorus from mineral repository (garnet and clinopyroxene) to the
487
coexisting melt in accordance with the high compatible behavior of the P in the liquid; 3)
488
dissolution of the apatite during subsequent melting of the eclogites and extraction of the liquid
489
accompanied by a general decrease of phosphorus concentration in the rock.
AC
CE P
TE
D
MA
NU
476
490
With regard to other locations, eclogitic rocks containing garnets and clinopyroxenes with the
491
similar exsolution assemblages, as those from Koidu kimberlite (Sierra Leone; Haggerty et al.,
492
1994; Fung and Haggerty, 1995), are suggested to be of ‘mantle’ origin, whereas eclogites from
493
Yangkou (Sulu terrane, China; Ye et al., 2000) and Zero kimberlite (South Africa; Schmickler et al.,
494
2004) are considered to represent remnants of subducted oceanic crust. However, lately the origin
ACCEPTED MANUSCRIPT
21
of Koidu eclogitic xenoliths was reconsidered with respect to oxygen isotope and trace element data
496
(Barth et al., 2001, 2002). It was suggested that low-MgO eclogites (with the exsolutions like those
497
in Udachnaya and Zarnitsa samples) represent fragments of processed oceanic crust, subducted and
498
partially melted to produce TTG suites, i.e. they are related to residual eclogites, which were
499
subsequently emplaced into the lithospheric environment (Barth et al., 2001, 2002). Returning to
500
Udachnaya and Zarnitsa case, the protoliths of studied group B/C eclogites from these localities are
501
assumed to undergo nearly analogous geological processing during Archean-Proterozoic time
502
(Jacob and Foley, 1999) when the tectonic provinces of Siberian craton were formed (Rosen et al.,
503
2005) and intensive growth of the crust had taken place (Smelov et al., 2001; Shatsky et al., 2005).
504
In contrast, the protolith of the group A eclogite from Obnazhennaya kimberlite may have a hybrid
505
crust/mantle origin (Taylor et al., 2003) or originate from the lower cumulate parts of oceanic crust,
506
the subduction of which resulted to the formation of high-MgO metapyroxenitic (or metagabbroic)
507
eclogites (Barth et al., 2002). The latter case may well explain the formation and preservation of
508
exsolution textures of different scale in garnet (thin rutile + quartz needles) and clinopyroxene
509
(coarse orthopyroxene lamellae and thin rutile rods) hosts if the protolith of the eclogite was
510
subjected to long-term recycling and transformation long before the entrainment of the kimberlite.
AC
CE P
TE
D
MA
NU
SC R
IP
T
495
511
To constrain the subsolidus (or near-subsolidus) history of studied eclogites predating
512
exsolution processes, reconstructed major-element compositions of garnet and clinopyroxene have
513
been calculated (Table 6). Recalculated garnet compositions have higher TiO2 contents, ranging
514
from 0.74 to 1.18 wt % in Udachnaya and Zarnitsa eclogites and being equal to 0.37 wt % in
515
Obnazhennaya eclogite. Taking into account experimental data (e.g. Zhang et al., 2003) high
516
titanium contents in mantle garnets (so-called Ti-majoritic garnets) are indicative of their high-
517
temperature and high-pressure stability. It should be noted that reconstructed garnet compositions
518
are characterized by minor disproportion of tetravalent and divalent cations inconsistent with
519
classical majorite substitution. Thus, it may indicate a fundamentally different mechanism of cation
ACCEPTED MANUSCRIPT
22
substitution in the studied garnets involving coupled NaTiVI-R2+AlVI and NaPIV-R2+SiIV
521
substitutions (Na2CaTi2Si3O12, NaCa2(AlTi)Si3O12, Na3Al2P3O12, Na3Ti2(Si2P)O12) (Ringwood and
522
Major, 1971; Haggerty et al., 1994). To estimate the stability conditions of the studied high-Ti
523
garnets, the average majorite component XcatMj was calculated for reconstructed garnet
524
compositions using the equations suggested by Collerson et al. (2010) (Table 6). The Fe2+ and Fe3+
525
contents were treated in accordance with charge balance (Locock, 2008). The highest value XcatMj =
526
0.144 in the garnet of group C eclogite from Udachnaya (UV662/11) is observed. Reconstructed
527
garnet composition from grospydite LUV134/10 has XcatMj = 0.081, whereas those from group B
528
eclogites UV58/10 (Udachnaya) and LUV184/10 (Zarnitsa) exhibit XcatMj equal to 0.063 and 0.054
529
respectively. The value XcatMj in reconstructed garnet from Obnazhennaya is only 0.030. According
530
to empirical barometer for majoritic garnets (Collerson et al., 2010) calculated XcatMj values
531
coincide to 6.8–8.4 GPa for the Udachnaya and Zarnitsa eclogites and to 6.3 GPa for the
532
Obnazhennaya eclogite.
CE P
TE
D
MA
NU
SC R
IP
T
520
Considering substitutions of Si and Ti in garnets (and clinopyroxenes), it should take into
534
account that their solubility depends not only on pressure but on temperature too (e.g. Zhang et al.,
535
2003; Collerson et al., 2010). The temperatures of stability for precursor minerals should be high
536
enough to accommodate all the components that were decomposed during exsolution process.
537
Nonetheless, it is fairly difficult to estimate the contribution of temperature while using only
538
experimental data. However, the projection of our pressure estimates for reconstructed garnet
539
compositions to cratonic geotherm provides temperature values as high as 1300–1400 °C for
540
Udachnaya and Zarnitsa samples and about 1250 °C for Obnazhennaya eclogite (Fig. 14).
AC
533
541
Among the mantle silicates, garnet is considered to represent the major repository for
542
phosphorus (Hermann and Spandler, 2007; Thompson, 1975). Incorporation of P into garnet is
543
strongly coupled with Na substitution (Bishop et al., 1976; Haggerty et al., 1994; Reid et al., 1976).
544
Thus, the precipitation of apatite from garnet is predictable. In our case, the ratio of Na, P and Ti in
ACCEPTED MANUSCRIPT
23
garnets was considered in detail. As shown in figure 9, the contents of Na2O and TiO2+P2O5 of
546
garnets are in a positive correlation. It is consistent with natural data for mantle xenoliths.
547
Considering MORB system as a bulk composition closest to eclogitic rocks, it was shown
548
experimentally that with increasing temperature and/or pressure, the Ti+P and Na contents in garnet
549
still align to positive trend line, and the ratio (Ti+P):Na varies with changing bulk composition and
550
physical parameters (Konzett and Frost, 2009). The sample from Obnazhennaya kimberlite exhibits
551
Ti+P and Na contents in reconstructed garnets, that overlap experimental data from bulk
552
composition II (Mg-basalt) of Konzett and Frost (2009) and data points correspond to 850–1125°C
553
and 3–8 GPa. In reconstructed garnet compositions of Udachnaya and Zarnitsa xenoliths, the Ti+P
554
values correspond to data points for the experiments at 950–1200°C and 7–8 GPa from bulk
555
composition I (MORB) (Konzett and Frost, 2009). However, the Na contents in the reconstructed
556
garnets of Udachnaya and Zarnitsa samples are unusually low in respect to tetravalent cations.
557
When arguing the origin of these eclogites from relic oceanic crust (in particular, from MORB
558
source), the explanation of low Na2O contents in garnet is required. The one of the reasons is that
559
low Na versus (Ti+P) contents in garnet might result from presence of a fluid/melt in the system
560
prior to or during exsolution. The latter may correspond to a precipitation of minerals in an open
561
system (Proyer et al., 2013). Petrographic examination of the eclogites from Udachnaya and
562
Zarnitsa reveal the findings of textures (pockets with secondary minerals, spongy-textures
563
symplectites after primary clinopyroxene and kelyphitic rims around garnets) that are likely
564
attributed to metasomatic treatment and/or partial melting (Fung and Haggerty, 1995; Misra et al.,
565
2004; Sobolev et al., 1999; Spetsius and Taylor, 2002). Moreover, studied eclogites contain rare
566
accessory apatite, what may be caused by the dissolution of apatite during the infiltration of fluid or
567
melt extraction. Thus, the metasomatic overprinting to the eclogitic assemblage is not unreasonable.
568
Experimentally it was shown that phosphorus in silicates substitutes Si on T-sites with a strong
569
preference for isolated SiO4 tetrahedra in orthosilicates rather than linked tetrahedral in chain
AC
CE P
TE
D
MA
NU
SC R
IP
T
545
ACCEPTED MANUSCRIPT
24
silicates (e.g. Brunet and Chazot, 2001). However, some phosphorus content in clinopyroxenes is
571
detectable (Konzett and Frost, 2009). Apatite precipitation in primary clinopyroxenes from studied
572
eclogites allows us to declare original pyroxenes could have had no less than 0.05 wt% of P2O5.
573
Considering experimental data, precursor pyroxenes are believed to be stable at temperatures 900–
574
1200 °C and pressures about 4–8 GPa (bulk composition I+II; Konzett and Frost, 2009). Further
575
findings of apatite lamellae in similar eclogitic pyroxenes may serve as complementary indicator of
576
ultra-high pressure stage in rock history.
NU
SC R
IP
T
570
Petrographic study of garnet and kyanite grains reveals that granular quartz inclusions in them
578
are usually monocrystalline, and the small subhedral unexposed ones tend to be surrounded by an
579
obvious birefringent halo. As shown by Korsakov et al. (2009), these inclusions are indicative of
580
their high-pressure origin. Since Raman frequency shifts are considered to be dependent on pressure
581
and temperature, the data for the SiO2 polymorphs (Hemley, 1987) were used to calculate residual
582
pressure (Pi) in the quartz and coesite inclusions. The quartz inclusions retain the pressure as high
583
as 1.5–2.6 GPa in the samples UV662/11 and UV58/10, whereas in the sample OLK1514 Pi ranges
584
within 0.9–1.4 GPa, and the lowest Pi (0.5 GPa) is calculated in LUV184/10. Coesite inclusions in
585
UV662/11 show residual pressure up to 0.9–1.4 GPa.
AC
CE P
TE
D
MA
577
586
The symplectitic intergrowths found in Udachnaya eclogites provide additional information for
587
the subsolidus reactions in the rocks. Type II feldspar-clinopyroxene symplectites were found only
588
in quartz eclogites. This observation coincides to data of Enami and Zhang (1990) attributed their
589
formation to retrograde reaction between primary omphacitic clinopyroxene and quartz.
590
Thermobarometric results assume the formation of these symplectites at pressure interval
591
corresponding to quartz stability field. Data applied for NCMAS system (Gasparik, 2014) suggest
592
temperatures of the type II symplectites formation (about 1000 °C) as high as those
593
geothermobarometrically estimated for re-equilibrated garnet-clinopyroxene assemblage. These P–
ACCEPTED MANUSCRIPT
25
594
T parameters are suggestive of near-isothermal decompression of the rocks probably during the
595
kimberlite eruption. From the combination of considered aspects including mineral chemistry, petrography and
597
spectroscopic facts with respect to the results of experimental petrology, the P–T history shown in
598
figure 14 can be constructed. The eclogitic rocks from diamondiferous kimberlite pipes Udachnaya
599
and Zarnitsa are supposed to be derived from the depths 210–260 km (stage UZ I; Fig. 14) to the
600
levels about 130–150 km near the graphite-diamond equilibrium (Kennedy and Kennedy, 1976).
601
The eclogite from diamond-free Obnazhennaya kimberlite may be derived from the lower depth
602
(Ob I; Fig. 14). According to geothermobarometric calculations, studied eclogites from Udachnaya
603
and Zarnitsa were re-equilibrated at 970–1080 °C and 4.1–4.9 GPa (stage UZ II; Fig. 14). The
604
Obnazhennaya group A eclogite was equilibrated at about 813 °C and 3.0 GPa under significantly
605
lower P–T conditions (stage Ob II; Fig. 14). Symplectite formation (omphacite breakdown) in
606
Udachnaya eclogites within quartz stability field (60–65 km) is related to stage UZ III on figure 14.
607
Presumable pressure-temperature paths of studied eclogites are also depicted (Fig. 14). Constraints
608
on the P–T history show that the vertical displacement of the rocks from depths of up to 260 km
609
was not a momentary.
AC
CE P
TE
D
MA
NU
SC R
IP
T
596
610
6.2. Implications for geodynamic environment
611
In geodynamic context, considered transformation history of the eclogites and their protoliths is
612
likely attributed to the Precambrian time of cratonic amalgamation when several terranes were
613
accreted to each other, and, on one hand, the lithospheric keel of the Siberian craton was originated,
614
while, on other hand, the continental crust was formed and thickened (e.g. Smelov et al., 2001;
615
Rosen et al., 2005).
616
Geotectonically kimberlites of Daldyn (Udachnaya and Zarnitsa pipes) and Kuoika
617
(Obnazhennaya pipe) kimberlite fields are located within granite-greenstone terranes and near the
618
ancient suture zones, i.e. near the former convergent plate boundaries. The collision within Anabar
ACCEPTED MANUSCRIPT
26
tectonic province (including Daldyn and Markha terranes) (Rosen et al., 2007) may have displaced
620
protoliths of Udachnaya and Zarnitsa eclogites to the depth of 210–260 km at the stage UZ I of the
621
P–T history (Fig.14). Subsequent upwelling may have led to the uplift of the mantle portions to the
622
levels of 130–150 km, where the eclogites were re-equilibrated in accordance with the ambient
623
mantle conditions. Considering the case of Obnazhennaya sample, the subduction of the Aekit
624
orogen under Birekte terrane probably has moved mafic protolith of Obnazhennaya eclogite to the
625
depth of about 200 km (stage Ob I on Fig. 14). Further upwelling in the lithosphere under
626
Obnazhennaya kimberlite pipe resulted in an ascent of the eclogitic protolith from depths of about
627
200 km to the levels of 90–100 km indicated by the geothermobarometric estimates. The
628
transportation of the rocks was accompanied by the pressure-temperature drop what account for the
629
abundant exsolution textures observed in studied eclogites.
D
MA
NU
SC R
IP
T
619
The reconstructed mantle P–T paths of eclogitic protoliths with the proposed geodynamical
631
environment are more or less consistent with the geodynamic model 2 of Spengler et al. (2006), that
632
explains the occurrence of peridotites derived from the Mantle Transition Zone at Otrøy (western
633
Norway). This model supposes the majorite formation in subcontinental lithospheric mantle
634
(SCLM) after hot upwelling, deep melting and accretion in the Archaean, when part of the lower
635
lithosphere was subducted, or delaminated, sinking to the Mantle Transition Zone. After subsequent
636
thermal equilibration the peridotite residue became buoyant (e.g. Ringwood, 1994), rising in a
637
subsolidus upwelling to underplate existing SCLM in the mid-Proterozoic, accompanied by
638
majorite exsolution (Spengler et al., 2006). The emplacement of eclogites into SCLM may be
639
related to the direct adding of subducted ocean floor (Helmstedt and Gurney, 1995) to SCLM or to
640
the intrusion of magmas derived from more deeply-subducted protoliths (Griffin and O’Reilly,
641
2007).
AC
CE P
TE
630
642 643
7. Conclusions
ACCEPTED MANUSCRIPT
27
A number of P–T indicative textures are presented in the studied set of mantle eclogites from
645
Yakutian kimberlite pipes. The Udachnaya and Zarnitsa eclogitic rocks were derived firstly from
646
depths 210–260 km to the level 130–150 km near the graphite-diamond boundary, where the
647
eclogites were re-equilibrated with relation to heat flow corresponding to the lithospheric mantle of
648
the central part of Siberian craton. The following decompression and cooling likely results in the
649
formation of exsolution textures with rutile + apatite + coesite in garnet and clinopyroxene hosts.
650
The rocks were lately uplifted to depths 60–65 km, where nearly all coesite was transformed into
651
quartz retaining high-pressure origin. The feldspar-pyroxene symplectites after primary omphacitic
652
clinopyroxenes were formed. Eclogite from Obnazhennaya kimberlite is supposed to undergo
653
pressure-temperature decrease of smaller scale as compared to Udachnaya and Zarnitsa eclogites.
MA
NU
SC R
IP
T
644
D
654
Acknowledgements
656
The research was supported by Russian Foundation of Basic Research (grant Nos. 12-05-31411 and
657
12-05-00508), by the grant of President of Russia (MD-1260.2013.5) and by the Ministry of
658
education and science of Russian Federation (project No. 14.B25.31.0032). We are grateful to L.V.
659
Usova, V.N. Korolyuk, N.S. Karmanov, M.V. Khlestov, A.T. Titov, S.Z. Smirnov to their
660
assistance with analytical work and A.S. Alifirov to the comprehensive support in writing of the
661
paper. We would like to thank D. Spengler and I. Katayama for their constructive reviews and T.
662
Hirajima for valuable comments during the preparation of the paper.
AC
CE P
TE
655
663 664
References
665
Ague, J.J., Eckert, J.O. Jr., 2012. Precipitation of rutile and ilmenite needles in garnet: implications
666
for extreme metamorphic conditions in the Acadian Orogen, U.S.A. American Mineralogist 79,
667
840–855.
ACCEPTED MANUSCRIPT
668 669
28
Ai, Y., 1994. A revision of the garnet–clinopyroxene Fe2+ – Mg exchange geothermometer. Contributions to Mineralogy and Petrology 115, 467–473. Alifirova, T.A., Pokhilenko, L.N., Ovchinnikov, Y.I., Donnelly, C.L., Riches, A.J.V., Taylor, L.A.,
671
2012. Petrologic origin of exsolution textures in mantle minerals: evidence in pyroxenitic
672
xenoliths from Yakutia kimberlites. International Geology Review 54, 1071–1092.
675 676
IP
SC R
pyroxenites from the Central Slave Craton, Canada. Journal of Petrology 48, 1843–1873.
NU
674
Aulbach, S., Pearson, N.J., O’Reilly, S.Y., Doyle, B.J., 2007.Origins of xenolithic eclogites and
Baker, B.M., Wyllie, P.J., 1992. High-pressure apatite solubility in carbonate-rich liquids: Implications for mantle metasomatism. Geochimica et Cosmochimica Acta 56, 3409–3422.
MA
673
T
670
Barron, B.J., Barron, L.M., Duncan, G., 2005. Eclogitic and ultra high pressure crustal garnets and
678
their relationship to Phanerozoic subduction diamonds, Bingara area, New England Fold Belt,
679
Eastern Australia. Economic Geology 100, 1565–1582.
TE
D
677
Barth, M.G., Rudnick, R.L., Horn, I., McDonough, W.F., Spicuzza, M.J., Valley, J.W., Haggerty,
681
S.E., 2001. Geochemistry of xenolithic eclogites from West Africa, part I: A link between low
682
MgO eclogites and archean crust formation. Geochimica et Cosmochimica Acta 65, 1499–1527.
683
Barth, M.G., Rudnick, R.L., Horn, I., McDonough, W.F., Spicuzza, M.J., Valley, J.W., Haggerty,
684
S.E., 2002. Geochemistry of xenolithic eclogites from West Africa, part 2: origins of the high
685
MgO eclogites. Geochimica et Cosmochimica Acta 66, 4325–4345.
AC
CE P
680
686
Beard, B. L., Fraracci, K. N., Taylor, L. A., Snyder, G. A., Clayton, R. A., Mayeda, T. K., Sobolev,
687
N.V. 1996. Petrography and geochemistry of eclogites from the Mir kimberlite, Yakutia, Russia.
688
Contributions to Mineralogy and Petrology 125, 293–310.
689 690
Bishop, F. C., Smith, J. V., Dawson, J. B., 1976. Na, P, Ti and coordination of Si in garnet from peridotite and eclogite xenoliths. Nature 260, 696–697.
ACCEPTED MANUSCRIPT
29
Bobrievich, A.P., Ilupin, I.P., Kozlov, I.T., Lebedeva, L.I., Pankratov, A.A., Smirnov, G.I.,
692
Kharkiv, A.D., 1964. Petrography and Mineralogy of Kimberlitic Rocks of Yakutia, Nedra,
693
Moscow, 191 pp. (in Russian)
T
691
Bose, K., Ganguly, J., 1995. Quartz–coesite transition revisited: Reversed experimental
695
determination at 500-1200 °C and retrieved thermochemical properties. American Mineralogist
696
80, 231–238.
SC R
IP
694
Boyd, F.R., Pokhilenko, N.P., Pearson, D.G., Mertzman, S.A., Sobolev, N.V., Finger, L.W., 1997.
698
Composition of the Siberian cratonic mantle: evidence from Udachnaya peridotites xenoliths.
699
Contributions to Mineralogy and Petrology 128, 228–246.
MA
NU
697
Brey, G.P., Kohler, T., 1990.Geothermobarometry in four-phase lherzolites II: New
701
thermobarometers and practical assessment of existing thermobarometers. Journal of Petrology
702
31, 1353–1378.
705 706 707 708
TE
CE P
704
Brunet, F., Chazot, G., 2001.Partitioning of phosphorus between olivine, clinopyroxene and silicate glass in a spinel lherzolite xenolith from Yemen. Chemical Geology 176, 51–72. Caporuscio, F.A., Smyth, J.R., 1990. Trace element crystal chemistry of mantle eclogites. Contributions to Mineralogy and Petrology 105, 550–561.
AC
703
D
700
Coleman, R.G., Lee, D.E., Beatty, L.B., Brannock, W.W., 1965. Eclogites and eclogites: Their differences and similarities. Geological Society of America Bulletin, 76, 483–508.
709
Collerson, K.D., Williams, Q., Kamber, B.S., Omori, S., Arai, H., Ohtani, E., 2010.Majoritic
710
garnet: a new approach to pressure estimation of shock events in meteorites andthe encapsulation
711
of sub-lithospheric inclusions in diamond. Geochimica et Cosmochimica Acta 74, 5939–5957.
712
Davis, G.L., Sobolev, N.V., Khar’kiv, A.D., 1980. New data on the age of Yakutian kimberlites
713 714 715
obtained by the uranium-lead method on zircons. Doklady Earth Sciences 254, 53–57. Dawson, J.B., Smith, J.V., 1986. Relationships between eclogites and certain megacrysts from the Jagersfontein kimberlite, South Africa. Lithos 19, 325–330.
ACCEPTED MANUSCRIPT
30
Dawson, J.B., 1980. Kimberlites and their xenoliths. New York, Springer-Verlag.
717
Ellis, D.J., Green, D.H., 1979. An experimental study of the effect of Ca upon the garnet–
718
clinopyroxene Fe–Mg exchange equilibria. Contributions to Mineralogy and Petrology 71, 13–
719
22.
722 723
IP
SC R
721
Enami, M., Zhang, Q., 1990.Quartz pseudomorphs after coesite in eclogites from Shandong province, East China. American Mineralogist 75, 381–386.
Essene, E.J., Fyfe, W.S., 1967. Omphacite in California metamorphic rocks. Contributions to
NU
720
T
716
Mineralogy and Petrology 15, 1–23.
Fung, A.T., Haggerty, S.E., 1995. Petrography and mineral compositions of eclogites from the
725
Koidu Kimberlite Complex, Sierra Leone. Journal of Geophysical Research 100, 20451–20473.
726
Gasparik, T., 2000. An internally consistently thermodynamic model for the system CaO–MgO–
727
Al2O3–SiO2 derived primarily from phase equilibrium data. Journal of Geology 108, 103–119.
728
Gasparik, T., 2014. Phase diagrams for geoscientists. An atlas of the Earth’s interior. Second
D
TE
CE P
729
MA
724
edition. New York, Springer.
Gasparik, T., Lindsley, D.H., 1980. Phase equilibria at high pressure of pyroxenes containing
731
monovalent and trivalent ions. In: Prewitt CT (ed), Reviews in Mineralogy, 1, Pyroxenes.
732
Mineralogical Society of America, Washington DC, 309–339.
733 734 735 736
AC
730
Griffin, W.L., Jensen, B.B., Misra, S.N., 1971. Anomalously elongated rutile in eclogite-facies pyroxene and garnet. Norsk Geologisk Tidsskrift 51, 177–185. Griffin, W.L., O’Reilly, S.Y., 2007. Cratonic lithospheric mantle: is anything subducted?. Episodes 30, 43–53.
737
Gudfinnsson, G.H., Presnall, D.C., 1996. Melting relations of model lherzolite in the system CaO–
738
MgO–Al2O3–SiO2 at 2.4–3.4 GPa and the generation of komatiites. Journal of Geophysical
739
Research 101, 27701–27709.
ACCEPTED MANUSCRIPT
746 747 748 749 750 751 752 753
T
IP
SC R
745
Helmstedt, H.H., Gurney, J.J., 1995. Geotectonic controls of primary diamond deposits: implications for area selection. Journal of Geochemical Exploration 53, 125–144. Hemley, R.J., 1987. Pressure dependence of Raman spectra of SiO2 polymorphs: α-quartz, coesite,
NU
744
Roberts Victor kimberlite pipe, South Africa. Physics and Chemistry of the Earth 9, 367–387.
and stishovite. Terrapub. Tokyo-AGU, Washington, DC, 347–359. Hermann, J., Spandler, C.J., 2007. Sediment melts at sub-arc depth: an experimental study. Journal
MA
743
Harte, B., Gurney, J.J., 1975. Evolution of clinopyroxene and garnet in an eclogite nodule from the
of Petrology 49, 717–740.
Hills, D.V., Haggerty, S.E., 1989.Petrochemistry of eclogites from the Koidu Kimberlite Complex,
D
742
from the upper mantle. Geophysical Research Letters 21, 1699–1702.
Sierra Leone. Contributions to Mineralogy and Petrology 103, 397–422.
TE
741
Haggerty, S. E., Fung, A.T., Burt, D.M., 1994. Apatite, phosphorus and titanium in eclogitic garnet
Holland, T.J.B., 1980. The reaction albite=jadeite+quartz determined experimentally in the range
CE P
740
31
600–1200 °C. American Mineralogist 65, 129–134. Hwang, S.L., Yui, T.F., Chu, H.T., Shen, P., Schertl, H.P., Zhang, R.Y., Liou, J.G., 2007. On the
755
origin of oriented rutile needles in garnet from UHP eclogites. Journal of Metamorphic Geology
756
25, 349–362.
757 758
AC
754
Ireland, T.R., Rudnick, R.L., Spetsius, Z., 1994. Trace elements in diamond inclusions from eclogites reveal link to Archean granites. Earth and Planetary Science Letters 128, 199–213.
759
Jacob, D., Jagoutz, E., Lowry, D., Mattey, D., Kudrjavtseva, G., 1994. Diamondiferous eclogites
760
from Siberia: remnants of Archean oceanic crust. Geochimica et Cosmochimica Acta 58, 5191–
761
5207.
762
Jacob, D.E., 2004. Nature and origin of eclogite xenoliths from kimberlites. Lithos 77, 295–316.
763
Jacob, D.E., Foley, S.F., 1999. Evidence for Archean ocean crust with low high field strength
764
element signature from diamondiferous eclogite xenoliths. Lithos 48, 317–336.
ACCEPTED MANUSCRIPT
32
Jerde, E.A., Taylor, L.A., Crozaz, G., Sobolev, N.V., 1993. Exsolution of garnet within
766
clinopyroxene of mantle eclogites: major and trace element chemistry. Contributions to
767
Mineralogy and Petrology 114, 148–159.
IP
769
Joanny, V., van Roermund, H., Lardeaux, J.M., 1991. The clinopyroxene/plagioclase symplectite in retrograde eclogites: potential geothermobarometer. Geologische Rundschau 80, 303–320.
SC R
768
T
765
Katayama, I., Parkinson, C.D., Okamoto, K., Nakajima, Y., Maruyama, S., 2000. Supersilicic
771
clinopyroxene and silica exsolution in UHPM eclogite and pelitic gneiss from the Kokchetav
772
massif, Kazakhstan. American Mineralogist 85, 1368–1374.
774
Kennedy, C.S., Kennedy, G.C., 1976. The equilibrium boundary between graphite and
MA
773
NU
770
diamond.Journal of Geophysical Research 81, 2467–2470. Kinny, P.D., Griffin, B.J., Heaman, L.M., Brakhfogel, F.F., Spetsius, Z.V., 1997. SHRIMP U-Pb
776
ages of perovskite from Yakutian kimberlites. Proceedings of Sixth International Kimberlite
777
Conference, V. 1: Kimberlites, related rocks, and mantle xenoliths. Russian Geology and
778
Geophysics 38, 97–105.
TE
CE P
780
Kirkpatrick, R.J., 1977. Nucleation and growth of plagioclase, Makaopuhi and Alae lava lakes, Kilauea Volcano, Hawaii. Geological Society of America Bulletin 88, 78–84.
AC
779
D
775
781
Konzett, J., Frost, D.J., 2009. The high P–T stability of hydroxyl-apatite in natural andsimplified
782
MORB–an experimental study to 15 GPa with implications for transport andstorage of
783
phosphorus and halogens in subduction zones. Journal of Petrology 50, 2043–2062.
784
Korolyuk, V.N., Lavrent’ev, Yu G., Usova, L.V., Nigmatulina, E.N., 2008. JXA-8100
785
microanalyzer: Accuracy of analysis of rock-forming minerals. Russian Geology and Geophysics
786
49, 165–168.
787
Korsakov, A.V., Perraki, M., Zhukov, V.P., De Gussem, K., Vandenabeelee, P., Tomilenko, A.A.,
788
2009. Is quartz a potential indicator of ultrahigh-pressure metamorphism? Laser Raman
ACCEPTED MANUSCRIPT
33
789
spectroscopy of quartz inclusions in ultrahigh-pressure garnets. European Journal of Mineralogy
790
21, 1313–1323.
calibration. Journal of Metamorphic Geology 18, 211–219.
T
792
Krogh Ravna E., 2000. The garnet–clinopyroxene Fe2+– Mg geothermometer: an updated
IP
791
Krogh Ravna E., Terry, M.P., 2004. Geothermobarometry of UHP and HP eclogites and schists –
794
an evaluation of equilibria among garnet–clinopyroxene–kyanite–phengite–coesite/quartz.
795
Journal of Metamorphic Geology, 22, 579–592.
798 799
NU
existing experimental data. Contributions to Mineralogy and Petrology 99, 44–48.
MA
797
Krogh, E. J., 1988. The garnet–clinopyroxene Fe-Mg geothermometer – a reinterpretation of
Lavrent’ev, Yu. G., Usova, L.V., Kuznetsova, A.I., Letov, S.V., 1987. X-Ray spectral quantometric microanalysis of main kimberlite minerals. Soviet Geology and Geophysics 5, 53–58.
D
796
SC R
793
Locock, A., 2008. An Excel spreadsheet to recast analyses of garnet into end-member components,
801
and a synopsis of the crystal chemistry of natural silicate garnets. Computers and Geosciences 34,
802
1769–1780.
CE P
TE
800
MacGregor, I.D., Carter, J.L., 1970. The chemistry of clinopyroxenes and garnets of eclogite and
804
peridotite xenoliths from the Roberts Victor mine, South Africa. Physics of the Earth and
805
Planetary Interiors 3, 391–397.
806 807 808 809
AC
803
MacGregor, I.D., Manton, W.I., 1986. Roberts Victor eclogites: ancient oceanic crust. Journal of Geophysical Research 91, 14093–14079. McKenzie, D., Jackson, J., Priestley, K., 2005. Thermal structure of oceanic and continental lithosphere. Earth and Planetary Science Letters 233, 337– 49.
810
Misra, K., Anand, M., Taylor, L.A., Sobolev, N.V., 2004.Multi-stage metasomatism of
811
diamondiferous eclogite xenoliths from the Udachnaya kimberlite pipe, Yakutia, Siberia.
812
Contributions to Mineralogy and Petrology 146, 696-714.
ACCEPTED MANUSCRIPT
34
Mposkos, E.D., Kostopoulos, D.K., 2001. Diamond, former coesite and supersilicic garnet in
814
metasedimentary rocks from the Greek Rhodope: a new ultrahigh-pressure metamorphic province
815
established. Earth and Planetary Science Letters 192, 497–506.
820 821 822 823
IP
SC R
819
Patel, S.C., Ravi, S., Thakur, S.S., Rao, T.K., Subbarao, K.V., 2006.Eclogite xenoliths from Wajrakarur kimberlites, southern India. Mineralogy and Petrology 88, 363–380.
NU
818
In Lesotho Kimberlites (Nixon P.H., ed.). Lesotho National Development Corp., Maseru, 67–75.
Pearson, G.R., Shaw, D.M., 1960. Trace elements in kyanite, sillimanite and andalusite. American Mineralogist 45, 808–817.
MA
817
Nixon, P.H., Boyd, F.R., 1973. The discrete nodule association in kimberlites of northern Lesotho.
Pollack, H.N., Chapman, D.S., 1977.On the regional variation of heat flow, geotherms, and lithospheric thickness. Tectonophysics 38, 279–296.
D
816
T
813
Proyer, A., Habler, G., Abart, R., Wirth, R., Krenn, K., Hoinkes, G., 2013. TiO 2 exsolution from
825
garnet by open-system precipitation: evidence from crystallographic and shape preferred
826
orientation of rutile inclusions. Contributions to Mineralogy and Petrology 166, 211–234.
CE P
TE
824
Reid, A.M., Brown, R.W., Dawson, J.B., Whitfield, G.G., Siebert, J.C., 1976.Garnet and pyroxene
828
compositions in some diamondiferous eclogites. Contributions to Mineralogy and Petrology 58,
829
203–220.
830 831 832 833
AC
827
Ringwood, A. E, 1994. Role of the transition zone and 660 km discontinuity in mantle dynamics. Physics of the Earth and Planetary Interiors 86, 5–24. Ringwood, A.E., Major, A., 1971. Synthesis of majorite and other high pressure garnets and perovskites. Earth and Planetary Science Letters 12, 411–418.
834
Rosen, O.M., Manakov, A.V., Suvorov, V.D., 2005. The collisional system in the northeastern
835
Siberian Craton and a problem of diamond-bearing lithospheric keel. Geotectonics (English
836
Translation) 39, 456–479.
ACCEPTED MANUSCRIPT
35
Rosen, O.M., Levsky, L.K., Zhuravlev, D.Z., Spetsius, Z.V., Rotman, A.Y., Zinchouk, N.N.,
838
Manakov, A.V., Serenko, V.P., 2007. The Anabar collision system as an element of the
839
Columbia supercontinent: 600 Ma of compression (2.0–1.3 Ga). Doklady Earth Sciences 417,
840
1355–1358.
IP
T
837
Rosenthal, A., Yaxley, G.M., Green, D.H., Hermann, J., Kovacs, I., Spandler, C., 2014. Continuous
842
eclogite melting and variable refertilisation in upwelling heterogeneous mantle. Scientific
843
Reports 4, 6099.
NU
SC R
841
Ruiz-Cruz, M.D., Sanz de Galdeano, C., 2013 Coesite and diamond inclusions, exsolution
845
microstructures and chemical patterns in ultrahigh pressure garnet from Ceuta (Northern Rif,
846
Spain). Lithos 177, 184–206.
MA
844
Sautter, V., Harte, B., 1990. Diffusion gradients in an eclogite xenolith from the Roberts Victor
848
kimberlite pipe: (2) kinetics and implications for petrogenesis. Contributions to Mineralogy and
849
Petrology 105, 637–649.
CE P
TE
D
847
Schmickler, B., Jacob, D.E., Foley, S.F., 2004. Eclogite xenoliths from the Kuruman kimberlites,
851
South Africa: geochemical fingerprinting of deep subduction and cumulate processes. Lithos 75,
852
173–207.
AC
850
853
Shatsky, V.S., Buzlukova, L.V., Jagoutz, E., Koz'menko, O.A., Mityukhin, S.I., 2005. Structure and
854
evolution of the lower crust of the Daldyn-Alakit district in the Yakutian Diamond Province
855
(from data on xenoliths). Russian Geology and Geophysics 46, 1252–1270.
856
Shee, S.R., Gurney, J.J., 1979. The mineralogy of xenoliths from Orapa, Botswana, in: Boyd, F.R.,
857
Meyer, H.O.A. (Eds.), The mantle sample: Inclusions in kimberlites and other volcanics. American
858 859 860
Geophysical Union, Washington, D.C., pp. 37–49. Shervais, J.W., Taylor, L.A., Lugmair, G.W., Clayton, R.N., Mayeda, T.K., Korotev, R.L., 1988. Geological Society of America Bulletin 100, 411–423.
ACCEPTED MANUSCRIPT
36
Smelov, A.P., Gabyshev, V.D., Kovach V.P., Kotov, A.B., 2001. General structure of the basement
862
of the eastern part of the North Asian craton, in: Tectonics, geodynamics, and metallogeny of the
863
territory of the Sakha Republic (Yakutia), MAIK “Nauka/Interperiodika”, Moscow, pp. 108–112
864
[in Russian].
IP
T
861
Smith, D.C., 1988. A review of the peculiar mineralogy of the “Norwegian coesite-eclogite
866
province”, with crystal-chemical, petrological, geochemical and geodynamical notes and an
867
extensive bibliography, in: Smith, D.C. (Ed.), Eclogites and eclogite-facies rocks. Elsevier,
868
Amsterdam, pp. 1–206.
NU
SC R
865
Smyth, J.R., T.C., McCormick, T.C., Caporuscio F.A., 1984. Petrology of a suite of eclogite
870
inclusions from the Bobbejaan kimberlite, I. Two unusual corundum-bearing kyanite eclogites,
871
in: Kimberlites, II. The Mantle and Crust-Mantle Relationships, Elsevier, Amsterdam, pp. 109–
872
119.
TE
D
MA
869
Smyth, J.R., Caporuscio F.A., McCormick, T.C., 1989. Mantle eclogites, Udachnaya kimberlite
874
pipe, Yakutia, Siberia: evidence of differentiation in the early Earth?. Earth and Planetary
875
Science Letters 93, 133–141.
877 878 879 880 881 882 883 884 885
Snoeyenbos, D.R., Koziol, A.M., Exsolution phenomena of UHP type in garnets from Western New
AC
876
CE P
873
England, USA, 2008. American Geophysical Union, Abstract No.V31E-07. Snyder, G.A., Taylor, L.A., Crozaz, G., Halliday, A.N., Beard, B.L., Sobolev, V.N., Sobolev, N.V., 1997. The origins of Yakutian eclogite xenoliths. Journal of Petrology 38, 85–113. Sobolev, N.V., 1977. Deep-seated inclusions in kimberlites and the problem of the composition of the upper mantle. Publications of AGU, Washington, DC. Sobolev, N.V., Lavrent’ev, Y.G., 1971. Isomorphic sodium admixture in garnets formed at high pressures. Contributions to Mineralogy and Petrology 31, 1–12. Sobolev, N.V., Yefimova, E.S., 2000. Composition and petrogenesis of Ti-oxides associated with diamonds. International Geology Review 42, 758–767.
ACCEPTED MANUSCRIPT
888 889
the Zagadochnaya kimberlite pipe in Yakutia. Journal of Petrology 9, 253–280. Sobolev, V.N., Taylor, L.A., Snyder, G.A., Sobolev, N.V., 1994. Diamondiferous eclogites from
T
887
Sobolev, N.V., Kuznetsova, I.K., Zyuzin, N.I., 1968. The petrology of grospydite xenoliths from
Udachnaya kimberlite pipe, Yakutia. International Geology Review 36, 42–64.
IP
886
37
Sobolev, V.N., Taylor, L.A., Snyder, G.A., Jerde, E.A., Neal, C.R., Sobolev, N.V., 1999.
891
Quantifying the effects of metasomatism in mantle xenoliths: constraints from secondary
892
chemistry and mineralogy in Udachnaya eclogites, Yakutia. International Geology Review 41,
893
391–416.
NU
SC R
890
Spengler, D., van Roermund, H.L.M., Drury, M.R., Ottolini, L., Mason, P.R.D., Davies, G.R.,
895
2006. Deep origin and hot melting of an Archaean orogenic peridotite massif in Norway. Nature
896
440, 913–917.
899 900
D
TE
898
Spetsius, Z.V., Taylor, L.A., 2002. Partial melting in mantle eclogite xenoliths: connections with diamond paragenesis. International Geology Review 44, 973–987.
CE P
897
MA
894
Spetsius, Z.V., 2004. Petrology of highly aluminous xenoliths from kimberlites of Yakutia. Lithos 77, 525–538.
Sun, S.-s., McDonough, W.F., 1989. Chemical and isotopic systematic of oceanic basalts:
902
implications for mantle composition and processes, in: Sauders, A.D., Norry, M.J. (Eds.),
903
Magmatism in the Ocean Basins. Geological Society Special Publications, 42, pp. 313–345.
904 905
AC
901
Taylor, L.A., Anand, M., 2004. Diamonds: time capsules from the Siberian Mantle. Chemie der Erde Geochemistry 64, 1–74.
906
Taylor, L.A., Neal, C.R., 1989. Eclogites with oceanic crustal and mantle signatures from the
907
Bellsbank kimberlite, South Africa, Part I: Mineralogy, petrography, and whole rock chemistry.
908
Journal of Geology 97, 551–567.
ACCEPTED MANUSCRIPT
38
Taylor, L.A., Snyder, G.A., Keller, R., Remley, D.A., Anand, M., Wiesli, R., Valley, J., Sobolev,
910
N.V., 2003.Petrogenesis of group A eclogites and websterites: Evidence from the Obnazhennaya
911
kimberlite, Yakutia: Contributions to Mineralogy and Petrology 145, 424–443.
IP
913
Thompson, R.N., 1975. Is upper-mantle phosphorous contained in sodic garnet? Earth and Planetary Science Letters 26, 417-424.
SC R
912
T
909
Watson, E.B., 1980. Apatite and phosphorus in mantle source regions: an experimental study of
915
apatite/melt equilibria at pressures to 25kbar. Earth and Planetary Science Letters 51, 322–335.
916
Whitney, D.L., Evans, B.W., 2010. Abbreviations for names of rock-forming minerals. American
920 921
MA
and “non-kimberlitic” ilmenite. Lithos 77, 819-840.
D
919
Wyatt, B.A., Mike, B., Anckar, E., Grutter, H., 2004. Compositional classification of “kimberlitic”
Ye, K., Cong, B., Ye, D., 2000.The possible subduction of continental material to depths greater
TE
918
Mineralogist 95, 185–187.
than 200 km. Nature 407, 734–736.
CE P
917
NU
914
Zhang, R.Y., Zhai, S.M., Fei, Y.W., Liou, J.G., 2003. Titanium solubility in coexisting garnet and
923
clinopyroxene at very high pressure: the significance of exsolved rutile in garnet. Earth and
924
Planetary Science Letters 216, 591–601.
925
AC
922
ACCEPTED MANUSCRIPT
926
39
Figure captions
927
Fig. 1. Schematic map of the Siberian craton showing boundaries of the craton (1) and its terranes
929
(2), surface exposures of Precambrian rocks within Anabar shield (3), location of Mesozoic (4) and
930
Paleozoic (5) kimberlite fields. The locations of the Udachnaya, Zarnitsa and Obnazhennaya
931
kimberlite pipes (6), from which the studied xenoliths are derived, are also shown (modified after
932
Rosen et al., 2005 and Alifirova et al., 2012). The Anabar Province consists of the Daldyn, Markha
933
and Magan terranes, and the Olenyok Province consists of the Hapschan, Birekte and Aekit
934
terranes.
MA
NU
SC R
IP
T
928
935
Fig. 2. Petrographic features of quartz eclogites from Udachnaya. Primary garnet and clinopyroxene
937
(cpx-1) porhyroblasts surrounded by kelyphitic rims (Kel) and pyroxene-2 + feldspar symplectites
938
(Sym II), respectively, the irregular-shaped granular aggregates of quartz are shown with respect to
939
samples UV58/10 (A) and UV662/11 (B). Pockets with secondary minerals or melt pockets (MP; of
940
almost black color in pictures) are located both at grain boundaries and within quartz granular
941
aggregates.
TE
CE P
AC
942
D
936
943
Fig. 3. Scale and appearance of exsolution textures in garnets. A – quartz + rutile+apatite lamellae
944
in the garnet of eclogite LUV184/10 (Zarnitsa). B – precipitates of quartz and rutile in the garnet of
945
eclogite OLK1514 (Obnazhennaya). C and D – an aureole of small quartz and apatite oriented
946
inclusions surrounding phlogopite inclusion in the garnet of eclogite LUV184/10 (Zarnitsa).
947 948
Fig. 4. Precipitates in eclogitic garnet porhyroblasts. A – intergrown rutile and quartz lamellae in
949
the garnet of eclogite UV662/11 (Udachnaya). B – coesite lamella in the garnet of eclogite
950
UV662/11 (Udachnaya). C – intergrown apatite and rutile needles in a garnet of grospydite
ACCEPTED MANUSCRIPT
40
951
LUV134/10 (Udachnaya). D – intergrown quartz and apatite precipitates in a garnet of eclogite
952
LUV184/10 (Zarnitsa).
T
953
Fig. 5. Exsolution textures in clinopyroxenes. A – rutile + apatite lamellae hosted in clinopyroxene
955
of eclogite UV662/11 (Udachnaya). B – coarse orthopyroxene lamellae included into clinopyroxene
956
host from eclogite OLK1514 (Obnazhennaya). C – separate apatite and rutile in clinopyroxene of
957
eclogite UV662/11 (Udachnaya). D – intergrown apatite platelet and rutile inclusion in
958
clinopyroxene of eclogite LUV184/10 (Zarnitsa).
NU
SC R
IP
954
MA
959
Fig. 6. Inclusions in kyanite (A) and garnet (B, C) in studied eclogites. A – oriented rutile needles in
961
kyanite matrix in grospydite LUV134/10 (Udachnaya). B - large covered quartz inclusion with a
962
strong radial crack pattern around, eclogite UV58/10 (Udachnaya). C – quartz inclusion surrounded
963
by an optical halo, eclogite UV58/10 (Udachnaya).
TE
CE P
964
D
960
Fig. 7. BSE images showing two types of symplectites in the grospydite LUV134/10. A – large
966
subgraphic intergrowths of quartz and garnet. B –tiny clinopyroxene-plagioclase intergrowths after
967
sodic clinopyroxene surrounding resorbed rutile lamella with minor ilmenite.
AC
965
968 969
Fig. 8. Ternary diagram for garnet composition. Colored crosses indicate compositions from
970
eclogites of this study. Star – diamondiferous eclogite xenoliths from Mir kimberlite, Yakutia,
971
Russia (Korsakov et al., 2009), squares – low-MgO eclogitic xenoliths from Koidu kimberlite
972
complex, Africa (Fung and Haggerty, 1995), diamonds – eclogites from Yangkou, Sulu UHP
973
metamorphic belt, China (Ye et al., 2000), inverted triangle – sanidine-orthopyroxene eclogite from
974
Zero kimberlite, South Africa (Schmickler et al., 2004), circle – garnet-biotite-kyanite gneiss from
975
Kimi area, Rhodope, Greece (Mposkos and Kostopoulos, 2001), triangles – garnet-rich
ACCEPTED MANUSCRIPT
41
migmatitesfrom Ceuta, Northern Rif, Spain (Ruiz-Cruz and Sanz de Galdeano 2013). Dashed lines
977
divide eclogitic garnet compositions on A, B and C groups according to Coleman et al. (1965).
978
Shaded grey area shows variation of garnet composition in eclogite and grospydite xenoliths from
979
Yakutian kimberlites, data combined from Sobolev (1977), Sobolev et al. (1968; 1994), Beard et al.
980
(1996), Snyder et al. (1997), Taylor et al. (2003), Spetsius (2004).
SC R
IP
T
976
981
Fig. 9. Major-element composition of garnets from eclogites. Legend and references are the same as
983
on Fig. 8. Eclogitic garnets from Koidu kimberlite (West Africa) and from Yangkou (Sulu, China)
984
are shown for the comparison. Dotted lines round the points of the samples. The Mg# =
985
{Mg/(Mg+Fe)}×100.
MA
NU
982
D
986
Fig. 10. Ternary diagram for sodic clinopyroxene compositions. Colored crosses indicate
988
compositions from eclogites of this study. Square – low-MgO eclogitic xenolith from Koidu
989
kimberlite complex, Africa (Fung and Haggerty, 1995). Clinopyroxene from Koidu xenolith (KEC-
990
81-12) contains both rutile and apatite lamellae. Diagram subdivisions are after Essene and Fyfe
991
(1967). Aug = Di + Hd + En + Fs + CaTs + CaEs.
CE P
AC
992
TE
987
993
Fig. 11. Major-element compositional features of clinopyroxenes from eclogite xenoliths. Legend
994
and references are the same as on Fig. 10. Dashed lines divide eclogites of A, B and C groups
995
according to Taylor and Neal (1989). Shaded grey areas show variation of clinopyroxene
996
composition in eclogite and grospydite xenoliths from Yakutian kimberlites, data combined from
997
Sobolev (1977), Sobolev et al. (1968; 1994), Beard et al. (1996), Snyder et al. (1997), Taylor et al.
998
(2003), Spetsius (2004).
999
ACCEPTED MANUSCRIPT
42
Fig. 12. Representative Raman spectra of quartz (A) and coesite (B) lamellae in host garnet
1001
porphyroblasts of eclogite xenolith UV662/11. Characteristic modes of the quartz are typed by a
1002
violet font, modes of the coesite are light blue, and those of the host garnet are magenta.
T
1000
IP
1003
Fig. 13. Geothermobarometry results obtained for studied set of eclogitic xenoliths from Udachnaya
1005
(A-C), Zarnitsa (D) and Obnazhennaya (E). Abbreviations: K88 –geothermometer after Krogh
1006
(1988), EG79 –geothermometer after Ellis and Green (1979), KR00 –geothermometer after Krogh
1007
Ravna(2000),
1008
orthopyroxenegeobarometer after Brey and Kohler (1990), KRT04 – geobarometers according to
1009
equations (1)-(3) from Krogh Ravna and Terry (2004). Quartz-coesite equilibrium is after Bose and
1010
Ganguly(1995); graphite-diamond transition is according to Kennedy and Kennedy (1976).
1011
Continental geotherm of 40 mW/m2 heat flow is from Pollack and Chapman (1977).
–
two-pyroxene
geothermometer
in
combination
with
garnet-
TE
D
MA
BK90
NU
SC R
1004
CE P
1012
Fig. 14. P–T paths of Udachnaya and Zarnitsa (UZ; purple arrows and area) and Obnazhennaya
1014
(Ob; light blue arrows and area) eclogites. The stages I (semitransparent colored rectangles) are
1015
indicated for the presumable pressure-temperature parameters of pre-exsolution assemblage. The
1016
stages II (areas with double hatching) correspond to the geothermobarometric calculations. The
1017
stage III (hatched rectangle) marks the breakdown of omphacitic clinopyroxene and the formation
1018
of spongy-textured type II symplectites. Majorite stability field (dark grey gradient area) and phase
1019
relationships for the CMAS system were constructed from Gasparik (2014). The isentrope for TP =
1020
1315 °C is from McKenzie et al. (2005). The solidus of ‘dry’ (nominally anhydrous) coesite
1021
eclogite after extraction of potassic dacitic-rhyodacitic melt is according to Rosenthal et al. (2014).
1022
The curve labelled ‘Qz/Coe-out’ indicates the stability of quartz or coesite in eclogite below this
1023
curve. The solidus of ‘dry’ peridotite is based on Gudfinnsson and Presnall (1996). The quartz-
AC
1013
ACCEPTED MANUSCRIPT
43
1024
coesite (Bose and Ganguly, 1995) and graphite-diamond phase changes (Kennedy and Kennedy,
1025
1976) as well as continental geotherm (Pollack and Chapman, 1977) are also shown.
AC
CE P
TE
D
MA
NU
SC R
IP
T
1026
ACCEPTED MANUSCRIPT
1027
44
Table captions
1028
Table 1
1030
Summarized sample information on their locality, rock type and minerals in exsolution textures.
1031
Group subdivision is after Coleman et al. (1965). Mineral abbreviations here and below are after
1032
Whitney and Evans (2010).
SC R
IP
T
1029
NU
1033
Table 2
1035
Volumetric proportions (in vol.%) of exsolution features in silicate hosts of studied eclogitic
1036
xenoliths from Yakutian kimberlites.
D
1037
MA
1034
Table 3
1039
Average major-element compositions of garnets in eclogitic xenoliths from Udachnaya, Zarnitsa
1040
and Obnazhennaya kimberlite pipes.
1041
Note: CP – porphyroblast core, RP – rim of porphyroblasts, S – symplectitic grains, SG – small
1042
grains, CSG – core of small grains, RSG – rim of small grains, CS – core of symplectitic grains, RS
1043
– rim of symplectitic grains, NP – near phlogopite inclusion, NH – near halo of quartz-apatite
1044
inclusions.
1045
member calculations are from Locock (2008). Specific components: NaTi garnet (NaTi grt)
1046
Na2CaTi2Si3O12, Majorite (Maj) Mg3MgSiSi3O12.
1
AC
CE P
TE
1038
Total Fe as FeO. The number of analyses (N) is also shown. The cation and end-
1047 1048
Table 4
1049
Average major-element compositions of clinopyroxenes in eclogitic xenoliths from Udachnaya,
1050
Zarnitsa and Obnazhennaya kimberlite pipes.
ACCEPTED MANUSCRIPT
45
Note: CP – porphyroblast core, RP – rim of porphyroblasts, SII –grains in type II symplectites, OL
1052
– orthopyroxene lamellae. 1 Total Fe as FeO. The number of analyses (N) is also shown. The cation
1053
and end-member calculations are from Katayama et al. (2000). Specific component: NaTi pyroxene
1054
(NaTi cpx) Na(Mg,Fe)0.5Ti0.5Si2O6.
IP
T
1051
SC R
1055
Table 5
1057
Pressure-temperature estimates for the studied mantle xenoliths. Temperatures are in °C and
1058
pressures are in GPa.
1059
Note: TK88 –garnet-clinopyroxene geothermometer after Krogh (1988), TEG79 – garnet-
1060
clinopyroxene geothermometer after Ellis and Green (1979), TKR00 – garnet-clinopyroxene
1061
geothermometer after Krogh Ravna(2000), TBK90 – single orthopyroxene geothermometer (Brey and
1062
Kohler, 1990), PBK90 – garnet-orthopyroxene geobarometer (Brey and Kohler, 1990), PKRT04-1 –
1063
pressure estimation according to equation (1) from Krogh Ravna and Terry (2004), Pg40 – pressure
1064
estimation in intersection of temperature line with geotherm 40 mW/m2 (Pollack and Chapman,
1065
1977), Tav – average of TK88, TEG79 and TKR00, Pav – average of pressure estimations without PBK90.
1066
AC
CE P
TE
D
MA
NU
1056
1067
Table 6
1068
Reconstructed mineral major-element (wt%) compositions.
1069
Note:
1070
Collerson et al. (2010). The cation and end-member calculations are from Locock (2008) for garnet
1071
and from Katayama et al. (2000) for clinopyroxene. Specific components: Schorlomite-Al
1072
Ca3Ti2SiAl2O12, Morimotoite Ca3TiFe2+Si3O12, NaTi garnet (NaTi grt) Na2CaTi2Si3O12,
1073
Morimotoite-Mg Ca3TiMgSi3O12, NaTi pyroxene (NaTi cpx) Na(Mg,Fe)0.5Ti0.5Si2O6.
1074
1
Total Fe as FeO. The XcatMj in garnet were calculated in accordance with equations from
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
Figure 1
TE
1076
D
1075
AC
CE P
1077
46
SC R
IP
T
ACCEPTED MANUSCRIPT
1079
NU
1078
Figure 2
AC
CE P
TE
D
MA
1080
47
1082 1083
Figure 3
AC
1081
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
48
1085 1086
Figure 4
AC
1084
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
49
1088 1089
Figure 5
AC
1087
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
50
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
1090 1091 1092
Figure 6
51
1094 1095
Figure 7
AC
1093
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
52
1096 1097 1098
Figure 8
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
53
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
1099 1100 1101
Figure 9
54
1102 1103 1104
Figure 10
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
55
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
1105 1106 1107
Figure 11
56
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
1108 1109 1110
Figure 12
57
ACCEPTED MANUSCRIPT
AC
CE P
TE
D
MA
NU
SC R
IP
T
1111
1112 1113 1114
Figure 13
58
1115 1116 1117
Figure 14
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
59
ACCEPTED MANUSCRIPT
1118
60
Table 1 Host mineral Group
Symplectite Grt
Cpx
Ky
T
Rock type
Udachnaya-East
Quartz eclogite
C
Qz, Rt, Coe, Ap
Rt, Ap
–
I, II
UV58/10
Udachnaya-East
Quartz eclogite
B
Rt, Qz, Ap, Ilm
Rt, Ilm
–
II
LUV134/10
Udachnaya-East
Grospydite
C
Rt, Ap
Rt, Ilm, Ap
Rt
I, II
B
Qz, Rt, Ap, Ilm
Rt, Ap, Ilm
–
–
Qz, Rt
Opx, Rt
–
–
LUV184/10
Zarnitsa
OLK1514
Obnazhennaya
MA
Bimineralic eclogite
Orthopyroxene eclogite
D
1119
TE
1120
AC
CE P
1121
A
IP
UV662/11
SC R
Kimberlite
NU
Sample
ACCEPTED MANUSCRIPT
1122
61
Table 2 Grt
Cpx
Ky
Sample Coe
Ap
Ilm
Rt
Ap
Ilm
UV662/11
0.8
1.1
0.1
0.1
–
1.8
0.1
–
UV58/10
0.6
0.3
–
0.1
<0.1
0.8
–
LUV134/10
0.6
–
–
0.1
–
1.0
LUV184/10
0.6
0.7
–
0.1
<0.1
0.7
OLK1514
0.3
0.5
–
–
–
0.4
AC
CE P
TE
D
MA
1124
SC R
0.1
Rt
–
–
–
–
0.1
0.1
–
0.3
0.1
0.1
–
–
–
–
11.5
–
NU
1123
Opx
T
Qz
IP
Rt
ACCEPTED MANUSCRIPT
Table 3 UV662/11
1127
RS G N= 3 39. 94 0.2 2 21. 71 <0. 06 11. 82 0.1 6 4.2 9 21. 53 0.1 2 0.1 0 99. 80
3.0 28 0.0 14 1.9 37 <0. 004 0.7 26 0.0 48 0.0 10 0.4 66 1.7 51 0.0 14 0.0 05 8.0 01
3.0 25 0.0 15 1.9 45 <0. 004 0.7 33 0.0 39 0.0 12 0.4 56 1.7 54 0.0 11 0.0 05 7.9 97
3.0 20 0.0 13 1.9 44 <0. 004 0.7 25 0.0 42 0.0 10 0.4 75 1.7 60 0.0 10 0.0 05 8.0 05
SG
NP
NH
CP
RP
SG
CP
RP
N= N= N= N= 6 6 3 4 39. 39. 39. 39. SiO2 13 39 13 11 0.3 0.2 0.2 0.1 TiO2 1 6 2 4 Al2 20. 21. 21. 21. O3 86 01 05 28 Cr2 0.0 0.0 0.0 <0. O3 6 6 6 06 FeO 19. 19. 19. 20. 1 38 45 52 63 Mn 0.4 0.4 0.4 0.4 O 8 9 9 2 Mg 5.5 5.5 5.5 8.5 O 9 3 8 5 13. 13. 13. 8.9 CaO 63 58 51 3 Na2 0.1 0.0 0.0 0.0 O 0 8 7 8 0.0 0.0 0.0 0.0 P2O5 8 7 7 8 Tota 99. 99. 99. 99. l 64 93 69 24 Calculation on 12 Oxygen
N= 4 38. 95 0.1 0 21. 21 <0. 06 20. 62 0.4 1 8.6 8 8.9 0 0.0 6 0.0 6 99. 02
N= 3 39. 12 0.1 3 21. 22 <0. 06 21. 08 0.4 2 8.2 7 9.1 5 0.0 6 0.0 4 99. 52
N= 8 39. 30 0.1 0 21. 35 <0. 06 22. 33 0.4 8 11. 14 4.9 7 0.0 4 0.0 6 99. 82
N= 10 39. 31 0.0 6 21. 52 <0. 06 22. 18 0.4 8 11. 19 4.9 1 0.0 4 0.0 8 99. 80
N= 3 39. 10 0.0 7 21. 50 <0. 06 22. 73 0.4 7 10. 84 4.7 2 0.0 4 0.0 5 99. 55
N= 3 39. 39 0.0 4 21. 68 <0. 06 22. 05 0.4 6 11. 62 4.4 0 0.0 3 0.0 7 99. 78
N= 3 39. 34 0.0 9 21. 32 <0. 06 22. 20 0.4 9 11. 15 4.9 6 0.0 4 0.0 6 99. 68
N= 4 41. 17 0.0 4 22. 61 0.2 0 14. 15 0.3 5 17. 56 3.8 6 <0. 03 <0. 04 99. 97
N= 4 41. 07 0.0 4 22. 53 0.1 8 14. 25 0.3 5 17. 57 3.8 5 <0. 03 <0. 04 99. 86
N= 3 41. 18 <0. 04 22. 76 0.1 7 14. 49 0.3 6 17. 35 3.7 7 0.0 3 <0. 04 100 .11
N= 4 39. 85 0.2 5 21. 63 <0. 06 12. 18 0.1 6 4.1 2 21. 52 0.1 0 0.0 8 99. 82
3.0 20 0.0 Ti 18 1.8 Al 97 0.0 Cr 04 1.1 Fe2+ 70 0.0 Fe3+ 81 0.0 Mn 32 0.6 Mg 43 1.1 Ca 27 0.0 Na 16 0.0 P 05 Tota 8.0 l 12 End-members
3.0 00 0.0 06 1.9 25 <0. 004 1.2 60 0.0 68 0.0 27 0.9 95 0.7 34 0.0 09 0.0 04 8.0 30
3.0 04 0.0 08 1.9 21 <0. 004 1.2 84 0.0 69 0.0 27 0.9 46 0.7 53 0.0 09 0.0 03 8.0 26
2.9 90 0.0 06 1.9 15 <0. 004 1.3 44 0.0 77 0.0 31 1.2 63 0.4 05 0.0 06 0.0 04 8.0 43
2.9 86 0.0 02 1.9 37 <0. 004 1.3 40 0.0 58 0.0 30 1.3 13 0.3 57 0.0 05 0.0 05 8.0 36
2.9 95 0.0 05 1.9 13 <0. 004 1.3 34 0.0 79 0.0 32 1.2 64 0.4 05 0.0 06 0.0 04 8.0 39
2.9 93 0.0 02 1.9 37 0.0 11 0.8 10 0.0 49 0.0 22 1.9 02 0.3 01 <0. 004 <0. 003 8.0 31
2.9 91 0.0 02 1.9 33 0.0 10 0.8 13 0.0 54 0.0 22 1.9 06 0.3 00 <0. 004 <0. 003 8.0 35
2.9 91 <0. 002 1.9 49 0.0 10 0.8 39 0.0 41 0.0 22 1.8 78 0.2 93 0.0 04 <0. 003 8.0 28
3.0 04 0.0 08 1.9 26 <0. 004 1.2 61 0.0 64 0.0 27 0.9 79 0.7 35 0.0 11 0.0 05 8.0 22
2.9 87 0.0 03 1.9 27 <0. 004 1.3 43 0.0 67 0.0 31 1.2 67 0.4 00 0.0 06 0.0 05 8.0 39
2.9 87 0.0 04 1.9 35 <0. 004 1.3 93 0.0 59 0.0 30 1.2 33 0.3 86 0.0 05 0.0 03 8.0 39
IP
SC R
NU
MA
D
3.0 18 0.0 13 1.9 13 0.0 04 1.1 88 0.0 71 0.0 32 0.6 41 1.1 16 0.0 10 0.0 04 8.0 10
T
RP
CS
RS
N= 3 39. 86 0.2 2 21. 73 <0. 06 11. 53 0.1 4 4.3 1 21. 87 0.0 9 0.0 7 99. 77
N= 3 39. 94 0.2 1 21. 69 <0. 06 11. 51 0.1 4 4.2 8 21. 83 0.0 7 0.0 5 99. 65
3.0 30 0.0 12 1.9 41 <0. 004 0.7 04 0.0 46 0.0 10 0.4 84 1.7 49 0.0 17 0.0 06 8.0 02
3.0 24 0.0 13 1.9 43 <0. 004 0.6 87 0.0 44 0.0 09 0.4 87 1.7 77 0.0 14 0.0 05 8.0 04
3.0 31 0.0 12 1.9 40 <0. 004 0.6 84 0.0 47 0.0 09 0.4 84 1.7 75 0.0 05 0.0 03 7.9 92
NaT i grt
1
1
1
1
1
1
1
1
1
Maj
2
3
2
3
1
2
2
2
1
1
1
1
Sps
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Prp
19
17
19
33
33
31
42
42
41
44
42
63
63
62
13
14
13
14
14
15
Alm
40
41
40
41
41
42
43
43
44
42
43
25
25
26
26
26
25
25
24
24
Grs
35
36
35
21
21
21
8
9
9
8
9
6
6
7
57
57
58
57
59
58
Adr Othe r
2
1
2
3
3
4
5
4
4
4
4
3
3
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Uv
1126
N= 4 39. 87 0.2 6 21. 76 <0. 06 12. 17 0.1 8 4.0 4 21. 58 0.0 8 0.0 7 99. 96
CS G N= 3 39. 88 0.2 3 21. 79 <0. 06 12. 11 0.1 6 4.2 1 21. 69 0.0 7 0.0 7 100 .16
CP
TE
CP
LUV134/10
SG
3.0 28 0.0 15 1.9 04 0.0 04 1.1 73 0.0 77 0.0 32 0.6 34 1.1 19 0.0 11 0.0 05 8.0 02
S
OLK1514
RP
Si
RP
LUV184/10
AC
CP
UV58/10
CE P
1125
62
1
ACCEPTED MANUSCRIPT
Table 4 LUV134/10
UV58/10
LUV184/10
UV662/11
OLK1514
RP
SII
CP
RP
SII
CP
RP
CP
RP
SII
CP
RP
OL
SiO2
N=3 55.0 5
N=3 55.0 1
N=3 51.7 9
N=4 56.1 0
N=4 56.2 9
N=3 51.7 3
N=3 53.3 7
N=3 53.4 9
N=4 54.5 8
N=4 54.6 3
N=4 49.8 9
N=3 55.2 9
N=3 55.5 1
TiO2
0.32
0.30
0.20
0.21
0.24
0.38
0.56
0.51
0.22
0.26
0.39
0.15
0.13
N=4 56.9 1 <0.0 4
16.0 5 <0.0 6
11.3 9 <0.0 6
13.7 7 <0.0 6
13.2 7 <0.0 6
7.54
6.41
5.95
5.29
0.69
Cr2O3
16.0 4 <0.0 6
<0.0 6
0.10
0.20
0.23
<0.0 6
FeO1
2.76
2.80
3.27
4.13
4.06
6.21
7.52
3.10
2.93
9.35
MnO
<0.0 6
<0.0 6
<0.0 6
<0.0 6
MgO
6.42
6.33
<0.0 6 11.2 3 19.4 8 3.19 <0.0 3 100. 55
6.68
6.96
10.9 1 8.29 <0.0 3 100. 18
11.0 6 8.25 <0.0 3 100. 24
<0.0 6 12.3 9 18.3 2 1.94 <0.0 3 98.5 1
<0.0 6 13.4 7 17.9 4 3.87 <0.0 3 100. 03
<0.0 6 13.9 8 18.5 0 3.54 <0.0 3 100. 15
0.06 <0.0 3 99.8 5
1.85 6 0.00 5 0.48 1 <0.0 02 0.07 4 0.02 4 <0.0 02 0.60 0 0.74 8 0.22 2 <0.0 01 4.00 9
1.97 9 0.00 5 0.57 3 <0.0 02 0.09 2 0.02 9 <0.0 02 0.35 1 0.41 2 0.56 7 <0.0 01 4.01 2
1.98 5 0.00 6 0.55 2 <0.0 02 0.08 6 0.03 3 <0.0 02 0.36 6 0.41 8 0.56 4 <0.0 01 4.01 4
CE P
IP
9.16
8.64
6.56
0.09
<0.0 6
<0.0 6
7.25
5.26
5.17
NU
SC R 6.12
<0.0 6 10.0 3
<0.0 6
<0.0 6
0.07
11.0 7 17.5 4 3.96 <0.0 3 100. 60
11.6 8 17.3 9 4.03 <0.0 3 100. 62
9.37
9.92
16.0 8 5.17 <0.0 3 99.9 6
16.3 7 4.70
99.8 0
12.0 9 19.1 2 1.09 <0.0 3 99.4 17
1.91 0 0.01 1 0.32 8 <0.0 02 0.19 2 0.00 0 <0.0 02 0.68 2 0.72 5 0.13 9 <0.0 01 3.98 5
1.94 7 0.01 5 0.27 5 0.00 3 0.13 6 0.09 3 0.00 2 0.60 2 0.68 5 0.28 0 <0.0 01 4.03 9
1.94 8 0.01 4 0.26 3 0.00 3 0.11 2 0.10 9 0.00 2 0.63 4 0.67 9 0.28 4 <0.0 01 4.04 7
1.96 8 0.00 6 0.38 9 <0.0 02 0.13 0 0.02 8 <0.0 02 0.50 4 0.62 1 0.36 1 <0.0 01 4.01 1
1.97 2 0.00 7 0.36 7 <0.0 02 0.14 7 0.00 9 <0.0 02 0.53 3 0.63 3 0.32 9 0.00 1 4.00 1
1.86 9 0.01 1 0.29 0 <0.0 02 0.27 6 0.03 8 0.00 6 0.67 5 0.76 7 0.07 9 <0.0 01 4.01 4
1.98 4 0.00 4 0.25 2 0.00 6 0.05 2 0.04 1 <0.0 02 0.72 0 0.68 9 0.26 9 <0.0 01 4.01 8
1.99 0 0.00 3 0.22 3 0.00 6 0.05 4 0.03 4 <0.0 02 0.74 6 0.71 0 0.24 6 <0.0 01 4.01 5
1.98 9 <0.0 01 0.02 9 <0.0 02 0.27 3 0.00 0 0.00 3 1.69 1 0.00 8 0.00 4 <0.0 01 3.99 8
MA
0.07
D
12.9 13.0 8 7 Na2O 6.94 6.91 <0.0 <0.0 K2O 3 3 100. 100. Total 57 51 Calculation on 6 Oxygen 1.92 1.92 Si 6 6 0.00 0.00 Ti 8 8 0.66 0.66 Al 1 2 <0.0 <0.0 Cr 02 02 0.08 0.08 2+ Fe 1 2 0.00 0.00 3+ Fe 0 0 <0.0 <0.0 Mn 02 02 0.33 0.33 Mg 5 0 0.48 0.49 Ca 7 0 0.47 0.46 Na 1 9 <0.0 <0.0 K 01 01 3.97 3.96 Total 0 9 End-members CaO
TE
Al2O3
T
CP
AC
1128
63
0.03
0.20
0.09 32.4 7 0.22
CaEs
6
6
1
0
0
3
1
1
0
0
1
0
0
0
CaTs
8
8
16
2
2
10
5
5
3
3
14
1
1
1
48
47
20
53
52
12
16
15
33
31
2
22
21
0
0
0
2
4
3
0
10
11
3
1
4
4
3
0
32
33
49
37
39
56
58
58
56
59
54
66
69
0
Jd Aeg Di+Hd
ACCEPTED MANUSCRIPT
64
En+Fs NaTi cpx
5
5
11
3
3
18
8
8
4
5
24
6
5
99
1
1
1
1
1
1
2
2
1
1
1
0
0
0
Kos
0
0
0
0
0
0
0
0
0
0
0
1
1
0
AC
CE P
TE
D
MA
NU
SC R
IP
T
1129
ACCEPTED MANUSCRIPT
65
1130
Table 5 T K88 / P g40
T EG79 / P g40
T KR00 / P g40
T BK90 / P BK90
UV662/11
948
969
994
–
4.0
4.1
4.3
1032
1036
1147
4.6
4.6
5.4
966
1143
1104
4.1
5.4
5.1
961
1048
1230
4.1
4.7
779
913
3.1
3.8
LUV134/10
982
1133
(P KRT04-1)
4.6
5.0
1132 1133 1134
IP
SC R
NU
MA
OLK1514
–
–
970 4.1 1071 4.9 1071 4.9
–
6.1
D
LUV184/10
TE
LUV134/10
CE P
UV58/10
T av / P av
T
Sample No.
AC
1131
1080 4.9
749
813
813
2.9
3.0
3.2
1096
–
1070
4.9
4.9
ACCEPTED MANUSCRIPT
Table 6 LUV18 4/10
OLK1 514
LUV13 4/10
SiO2
39.30
38.96
39.33
41.26
39.55
TiO2
1.18
Al2O3
20.47
21.08
21.09
22.45
21.47
Cr2O3
0.06
0.04
0.04
0.20
0.02
FeO1
19.03
20.43
22.06
14.05
12.09
MnO
0.47
0.42
0.47
0.35
0.16
MgO
5.48
8.47
11.00
17.44
4.09
CaO
13.42
8.89
4.96
3.84
21.40
Na2O
0.10
0.07
0.04
0.02
0.09
SiO
0.79
0.74
0.37
0.92
55.19
54.25
1.27
1.49
0.63
1.63
8.95
13.62
6.34
5.34
15.80
0.04
0.04
0.10
0.18
0.02
5.15
4.14
7.50
3.78
2.78
0.04
0.03
0.07
0.05
0.02
9.15
6.61
10.95
15.51
6.33
15.76
10.78
17.39
15.88
12.85
5.05
8.20
3.91
3.43
6.84
0.02
0.02
0.00
0.00
0.02
0.05
0.00
0.05
0.00
0.05
Tota 100.1 99.96 100.59 l 7 Calculation on 6 Oxygen
100.0 0
100.57
TiO
Total
99.64
0.11 99.25
Calculation on 12 Oxygen
0.09
SC R
1
Mn O Mg O CaO Na2 O K2O P2O
NU
MA
0.00
Al2 O3 Cr2 O3 FeO
0.12
2.43
99.82
D
0.11
99.97
99.90
2.989
2.998
3.003
Si
1.928
1.960
1.929
1.975
1.903
TE
P 2O 5
LUV13 4/10
52.78
2
K2O
OLK1 514
55.47
2
53.32
LUV18 4/10
T
UV58 /10
Clinopyroxene UV66 UV58 2/11 /10
IP
Garnet UV66 2/11
5
3.026
2.991
Ti
0.068
0.045
0.043
0.020
0.052
Ti
0.066
0.034
0.041
0.017
0.043
Al
1.858
1.907
1.889
1.922
1.921
Al
0.382
0.567
0.273
0.225
0.653
Cr
0.004
0.002
0.003
0.011
0.001
Cr
0.001
0.001
0.003
0.005
0.000
Fe2+
1.155
1.266
1.336
0.807
0.742
Fe2+
0.107
0.082
0.126
0.073
0.082
3+
0.049
0.040
0.103
0.040
0.000
Fe
3+
CE P
Si
0.070
0.045
0.066
0.046
0.025
Fe
Mn
0.031
0.027
0.030
0.022
0.010
Mn
0.001
0.001
0.002
0.002
0.001
Mg
0.629
0.969
1.246
1.888
0.462
Mg
0.493
0.348
0.596
0.827
0.331
Ca
1.107
0.731
0.404
0.299
1.741
Ca
0.610
0.408
0.681
0.609
0.483
Na
0.015
0.011
0.006
0.003
0.014
Na
0.354
0.561
0.277
0.238
0.465
K
0.001
0.001
0.000
0.000
0.001
P
0.007
0.007
0.006
0.000
0.007
0.000
0.003
0.000
0.003
Total
7.971
8.003
8.016
8.016
7.979
P 0.003 Tota 3.995 l End-members CaE s 7 CaT s 8
4.003
4.034
4.011
3.963
3
4
1
8
4
8
3
11
19
48
10
17
42
6
4
11
4
0
48
33
55
56
27
5
4
8
17
7
AC
1135
66
K
End-members Schorlomit e-Al Morimotoi te
1 2
2
1
NaTi grt Morimotoi te-Mg
1
1
Sps
1
1
1
1
Prp
20
32
41
63
2
1
Jd
1
Aeg Di+ Hd En+ Fs
15
ACCEPTED MANUSCRIPT
41
42
44
26
26
Grs
31
20
7
6
55
1
3
2
1 0.063
1 0.054
1 0.030
XcatMj
4 0.144
2 0.081
SC R
1136
AC
CE P
TE
D
MA
NU
1137
4
IP
Adr Other
7
T
Alm
NaT i cpx
67
4
2
5
ACCEPTED MANUSCRIPT
1138
Highlights
1139
Apatite and quartz/coesite exsolutions were found in garnet and clinopyroxene hosts
1141
Eclogite and grospydite rocks were derived from depths about 200–260 km
1142
Original rocks were transformed during stepwise decompression and cooling
AC
CE P
TE
D
MA
NU
SC R
IP
T
1140
68
S0024-4937(15)00028-6 doi: 10.1016/j.lithos.2015.01.020 LITHOS 3506
To appear in:
LITHOS
Received date: Accepted date:
29 May 2014 28 January 2015
Please cite this article as: Alifirova, T.A., Pokhilenko, L.N., Korsakov, A.V., Apatite, SiO2 , rutile and orthopyroxene precipitates in minerals of eclogite xenoliths from Yakutian kimberlites, Russia, LITHOS (2015), doi: 10.1016/j.lithos.2015.01.020
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Apatite, SiO2, rutile and orthopyroxene precipitates in minerals of eclogite xenoliths from
2
Yakutian kimberlites, Russia
3
Alifirova T.A.1,*, Pokhilenko L.N.1, Korsakov A.V.1
T
1
V.S. Sobolev Institute of Geology and Mineralogy of Siberian Branch of Russian Academy of
6
SC R
1
IP
4 5
1
Sciences, Novosibirsk, 630090, Russian Federation
NU
7
* Corresponding author: V.S. Sobolev Institute of Geology and Mineralogy of Siberian Branch of
9
Russian Academy of Sciences, Academician Koptyug ave. 3, Novosibirsk, 630090, Russian
10
MA
8
Federation. E-mail: [email protected]. Phone:7(383)330 80 68
D
11
Abstract
13
Eclogite mantle xenoliths from the central part of Siberian craton (Udachnaya and Zarnitsa
14
kimberlite pipes) as well as from the northeastern edge of the craton (Obnazhennaya kimberlite)
15
were studied in detail. Garnet and clinopyroxene show evident exsolution textures. Garnet
16
comprises rutile, ilmenite, apatite, and quartz/coesite oriented inclusions. Clinopyroxene contains
17
rutile (± ilmenite) and apatite precipitates. Granular inclusions of quartz in kyanite and garnet
18
usually retain features of their high-pressure origin. According to thermobarometric calculations,
19
studied eclogitic suite was equilibrated within lithospheric mantle at 3.2–4.9 GPa and 813–1080 °C.
20
The precursor composition of garnets from Udachnaya and Zarnitsa eclogites suggests their stability
21
at depths 210–260 km. Apatite precipitation in clinopyroxenes of Udachnaya and Zarnitsa allows us
22
to declare that original pyroxenes could have been indicative of their high P–T stability. Raman
23
spectroscopic study of quartz and coesite precipitates in garnet porphyroblasts confirms our
24
hypothesis on the origin of the exsolution textures during pressure-temperature decrease. With
AC
CE P
TE
12
ACCEPTED MANUSCRIPT
2
25
respect to mineralogical data, we suppose the rocks to be subjected to stepwise decompression and
26
cooling within mantle reservoir.
Keywords: exsolution, eclogite, grospydite, coesite, mantle xenoliths, Siberian craton
IP
28
T
27
SC R
29
1. Introduction
31
Considering all the deep-seated mantle xenoliths from kimberlite pipes worldwide, eclogites and
32
grospydites take a special place of mantle rock types. Although eclogitic rocks are one the main
33
sources of diamonds from kimberlite pipes (e.g. Reid et al., 1976; Sobolev, 1977; Taylor and
34
Anand, 2004), they are less abundant among the mantle rocks transported to the surface by
35
kimberlite melts. A number of works was devoted to the investigation of these rocks found in
36
Yakutian kimberlites (e.g. Sobolev et al., 1968; Spetsius, 2004), including coesite- and diamond-
37
bearing varieties.
CE P
TE
D
MA
NU
30
Mantle xenoliths with minerals comprising exsolution features represent valuable source of
39
information on the composition and stability of precursor phases and their transformation in
40
dependence on environmental conditions (temperature, pressure, and oxygen fugacity). In a light of
41
special interest to eclogitic rocks as potential hosts of diamonds, the exsolution textures have a
42
genetic significance. Among the population of eclogite xenoliths, the exsolution textures in garnet
43
and clinopyroxene are more or less common, being described in kimberlites of Yakutia, Russia
44
(Jerde et al., 1993; Taylor et al., 2003), South Africa (Harte and Gurney, 1975; Sautter and Harte,
45
1990; Schmickler et al., 2004), India (Patel et al., 2006), and other localities. Similar textures were
46
described in eclogitic bodies from metamorphosed complexes under ultra-high pressure (UHP)
47
conditions (e.g. Smith, 1988). Garnet lamellae in clinopyroxenes are likely to be the most abundant
48
exsolution textures found in eclogite mantle xenoliths (e.g. Jerde et al., 1993). This fact in turn
AC
38
ACCEPTED MANUSCRIPT
3
49
becomes a reason to suggest the exsolution phenomenon as a process responsible for the formation
50
of some upper-mantle derived eclogites (e.g. Smyth et al., 1984). Garnet from mantle and UHP metamorphic eclogites commonly contain oriented inclusions of
52
rutile and/or clinopyroxene considered as a result of exsolution from the precursor high-Ti or high-
53
Si garnet (Griffin et al., 1971) or formed by alternative ways (Hwang et al., 2007). In a few cases,
54
the oriented rutile needles are described in some garnet grains from a diamondiferous eclogite
55
xenolith (Korsakov et al., 2009). Apatite was found to be exsolved in garnet grains and rarely in
56
clinopyroxene porphyroblasts from eclogites of Sulu terrain, China (Ye et al., 2000), and West
57
Africa (Fung and Haggerty, 1995; Haggerty et al., 1994). Exsolution of SiO2 polymorphs in form of
58
quartz or coesite was observed in clinopyroxenes (e.g. Katayama et al., 2000) and garnets (Mposkos
59
and Kostopoulos, 2001; Ague and Eckert, 2012; Ruiz-Cruz and Sanz de Galdeano, 2013) of UHP
60
metamorphic eclogites and pelitic rocks. Alpha-quartz inclusions together with rutile were
61
described in garnets of sanidine-orthopyroxene eclogite xenolith from South Africa (Schmickler et
62
al., 2004). However, silica precipitates in minerals of eclogite mantle xenoliths were not considered
63
as exsolution products earlier.
CE P
TE
D
MA
NU
SC R
IP
T
51
This contribution is focused on a thorough mineralogical and petrographic examination of rare
65
eclogite mantle xenoliths with exsolution textures in garnet and clinopyroxene porphyroblasts
66
collected from Yakutian kimberlite pipes (Siberian platform, Russia). Major-element composition
67
data are used to constrain pressure-temperature conditions attending these rocks on various stages
68
of their transformation before the entrainment to the surface by kimberlitic melt.
AC
64
69 70
2. Geological setting
71
Mantle xenoliths with eclogitic paragenesis from two diamondiferous kimberlite pipes Udachnaya
72
and Zarnitsa were taken for this study. These two pipes are situated at Daldyn kimberlite field,
73
Daldyn-Alakit region of Yakutian kimberlite province on Siberian platform. The kimberlites
ACCEPTED MANUSCRIPT
4
intrusion was taken place in Devonian time according to U-Pb dating (Udachnaya 367±5 Ma, Kinny
75
et al., 1997; Zarnitsa 360±4 Ma, Davis et al., 1980). In geotectonic point of view, these kimberlites
76
are located within Markha granite-greenstone terrane near the suture with Daldyn granulite-gneiss
77
terrane of Siberian craton (Fig. 1) and include crustal and mantle materials as xenoliths. These
78
terranes were collided to each other at Paleoproterozoic time (2.6–2.2 Ga, Rosen et al., 2005)
79
forming a part of Anabar province (Fig. 1) (Rosen et al., 2005).
SC R
IP
T
74
The eclogite mantle xenolith from diamond-free Obnazhennaya pipe (Kuoika kimberlite field,
81
Lower Olenyok region; 148±3 Ma; Davis et al., 1980) is characterized for the comparison.
82
Tectonically the pipe is located within Birekte granite-greenstone terrane of Olenyok province (Fig.
83
1) (Rosen et al., 2005). At mid-Proterozoic time (2.3–1.9 Ga) Anabar province began the
84
amalgamation with Tungus and Olenyok provinces and at Neoproterozoic (1.9–1.8 Ga) all these
85
parts were accreted to terranes of Aldan province (Fig. 1), finally forming Siberian craton (Rosen et
86
al., 2005).
MA
D
TE
CE P
87
NU
80
3. Analytical techniques
89
The xenoliths listed in Table 1 were examined in polished sections with 30 μm thickness. The
90
petrographical examination and analytics were performed at V.S. Sobolev Institute of Geology and
91
Mineralogy, Siberian Branch of Russian Academy of Sciences (IGM), Novosibirsk, Russia.
92
Major-element compositions of minerals were determined by electron microprobe analysis using a
93
JEOL JXA-8100 electron microprobe at IGM. Analyses were conducted using an acceleration
94
voltage of 20 kV, a focused beam with a current of 10 nA, counting times of 20–30 s, and standard
95
PAP correction procedures (e.g. Lavrent’ev et al., 1987; Korolyuk et al., 2008). Precision and
96
accuracy were monitored using natural and synthetic standards that were measured at regular
97
intervals during each analytical session. Intra- and intergrain homogeneity within individual
98
samples was assessed by measuring 3–10 points in each grain. Detection limits are typically <0.04
AC
88
ACCEPTED MANUSCRIPT
5
wt% for SiO2, TiO2, Al2O3, MgO, CaO, Na2O, K2O, P2O5 and <0.05–0.07 wt% for FeO, MnO, and
100
Cr2O3.The Tescan scanning electron microscope was used to obtain back-scattered electron (BSE)
101
images and X-ray energy-dispersive system (EDS) for compositional data. Raman spectroscopic
102
study was performed on a Horiba Jobin Yvon LabRam HR800 confocal microspectrometer
103
equipped with an Olympus BX41 optical microscope. The spectroscopic technique was conducted
104
using 514 nm wavelength laser, grating 1800, hole 100 μm for the most of analyzed objects and 50
105
μm for inclusions smaller than 1 μm in thickness. The estimated spectral resolution is 0.5 cm–1. The
106
standard of pure silicon was used for the calibration.
NU
SC R
IP
T
99
Volume proportions of precipitates were estimated by following procedure. The host minerals in
108
thin sections were taken for the calculation. The areas of the interest were photographed in reflected
109
light and in back-scattered electrons to define minerals making up precipitates. Several shots from
110
optical microscope were taken to construct whole-grain composition. Analyzed areas were from 1.8
111
to 3 mm2 for the most of thin lamellae and about 30mm2 in case of coarse orthopyroxene lamellae
112
in eclogite OLK1514. The Plotcalc application (www.plotcalc.com) was used to obtain two-
113
dimensional proportions. Precipitates in garnet are composed of several minerals with different
114
morphology and commonly intergrown with each other. Thus, despite the high symmetry of garnet,
115
the volume proportions of lamellae might be underestimated, if assumed to be equal to surface ones.
116
Thus, to obtain volume proportions from the areal ones in garnet porphyroblasts, the correction
117
procedure was taken using the simplest reliable method (Kirkpatrick, 1977). The correction factor
118
was applied to the number of crystals to which the average surface squares were calculated. Surface
119
estimates of precipitates in clinopyroxene crystals are assumed to be equal to 3D proportions.
120
Calculated estimates for two to three host grains were averaged and shown in Table 2. The range of
121
volume proportions lies within 10% error for inclusions 3–5 μm wide and within about 20% for
122
smaller precipitates. The lowest range of volume estimates (<10%) are typical of coarse
123
orthopyroxene lamellae of eclogite OLK1514. To estimate chemical composition of precursor
AC
CE P
TE
D
MA
107
ACCEPTED MANUSCRIPT
6
minerals, the volume proportions of the host minerals and their lamellae were summarized after
125
conversion to mass percentage. The molar volumes of all chemical components were taken at
126
standard conditions to constrain chemical composition in weight percent.
T
124
IP
127
4. Xenolith petrography
129
On the basis of dominant primary mineralogy, the studied eclogites can be classified into four
130
groups: 1) quartz eclogites, 2) grospydite (kyanite eclogite with garnet of grossular composition), 3)
131
bimineralic eclogite and 4) orthopyroxene-bearing eclogite. Locality, rock type and mineral
132
assemblages of the samples are given in Table 1.
133
1) Quartz eclogites from Udachnaya (UV662/11 and UV58/10) are medium- to coarse-grained.
134
Garnets of saturated orange-red color compose subhedral porphyroblasts 3 to 7 mm in diameter.
135
Kelyphitic rims up to 0.2 mm in width are developed around garnets (Fig. 2). Clinopyroxenes
136
are dark green anhedral grains, varying from 2 to 10 mm in diameter. Secondary clinopyroxene-
137
feldspar symplectitic intergrowths are developed along the cracks and grain boundaries of
138
primary omphacitic clinopyroxenes, forming common “spongy” textures (Fig. 2). Straight grain
139
boundaries with typical triple junctions are well preserved in this group of eclogites. Quartz in
140
the eclogites is presented by irregular-shaped granular aggregates up to 4 mm in diameter with
141
separate grains of 0.5–1 mm in width (Fig. 2). Some of these aggregates contain needle-like
142
rutile inclusions. Coarse symplectitic intergrowths of quartz granular aggregates and garnet
143
were found in eclogite UV662/11. Areas with subrounded outlines up to 1–1.5 mm wide are
144
observed between primary minerals (Fig. 2A). They are composed of various secondary
145
products like oxides, sulfides, chlorite, amphibole, K-bearing minerals (feldspar, phlogopite),
146
carbonates, and spinels. Rare separate grains (<15 μm long) of apatite were found within these
147
pockets in the sample UV58/10.
AC
CE P
TE
D
MA
NU
SC R
128
ACCEPTED MANUSCRIPT
7
2) Grospydite xenolith from Udachnaya kimberlite (LUV134/10) shows complex fine- to medium-
149
grained texture. Kyanite grains up to 3 mm long are pale blue in color. They are mostly euhedral
150
and their simple {100} and/or {010} twinning is common. Garnet grains being from 0.5 to 2
151
mm in size have pale orange color. Two generations of garnet are observable. Older garnet-1 is
152
presented by subhedral to rounded individual grains. Younger garnet-2 is characterized by
153
elongated grains and shows vermicular morphology and is intergrown with quartz granular
154
aggregates, forming coarse symplectites up to 8-10 mm in width. Clinopyroxene grains are of
155
light green color with a light blue tint and up to 10 mm in diameter. They tend to be irregularly
156
shaped. Kyanite and garnet-1 grains are poikiloblastically included by the clinopyroxene
157
porphyroblasts. Despite the exceptional freshness of the sample, the primary clinopyroxene
158
(clinopyroxene-1) is nearly all penetrated by symplectites composed of spongy clinopyroxene-2
159
+ feldspar, with unreacted relics preserving in the symplectitic matrix. However, triple junctions
160
on grain boundaries are found between kyanite, garnet-1 and clinopyroxene-1 grains. Inclusions
161
of quartz are often found in kyanite grains. Pockets (usually <100 μm wide) with secondary
162
minerals (Ba-Sr-sulfates, sulfides, K-bearing minerals, oxides, amphibole) were also found in
163
this xenolith.
AC
CE P
TE
D
MA
NU
SC R
IP
T
148
164
3) Bimineralic eclogite from Zarnitsa kimberlite (LUV184/10) has fine- to medium-grained texture
165
with equigranular garnet and clinopyroxene porphyroblasts. Garnet grains are pale orange-red
166
colored and have a grain size ranging from 0.5–1 to 5 mm in diameter. Small garnet grains are
167
irregularly shaped, whereas larger ones tend to be euhedral. Pale green clinopyroxene of up to
168
3–4 mm long is patchy replaced by secondary alteration products (serpentine and chlorite).
169
Despite the abundant alteration, in some places the triple junctions between garnet and
170
clinopyroxene grains are preserved. Pockets with rounded outlines (up to 0.5 mm wide) filled
171
out by secondary minerals were also detected in the eclogite.
ACCEPTED MANUSCRIPT
8
4) Orthopyroxene-bearing eclogite from Obnazhennaya kimberlite (OLK1514) exhibits medium to
173
coarse grained texture alternating with the areas of lamellar texture. Pale orange-pink garnet
174
porphyroblasts are subhedral grains 3 to 5mm in diameter. Pale green anhedral clinopyroxene
175
porphyroblasts up to 8 mm long contain coarse orthopyroxene lamellae 30–100 μm wide and 1–
176
3 mm long. Grain boundaries between garnet and clinopyroxene are joined at 120° from place
177
to place. Individual grains of orthopyroxene are not typical of this sample. The eclogite is only
178
weakly altered, containing minor serpentine on grain boundaries contacting with kimberlite.
179
Primary assemblage minerals of studied eclogites include evident exsolution features considered in
180
detail separately.
MA
NU
SC R
IP
T
172
181
4.1. Exsolution textures
183
4.1.1. Garnet host
184
Coarse garnet porphyroblasts (up to 7 mm in diameter) from all studied xenoliths contain oriented
185
mineral inclusions considered as exsolution lamellae. Exsolved mineral assemblages for studied
186
samples are listed in Table 1. Precipitates are usually concentrated at the cores of large garnet
187
crystals and characterized by varying density of distribution in host garnets from sample to sample
188
(Table 2). Numerically garnets from Udachnaya and Zarnitsa xenoliths comprise 0.7–2.1 vol.% of
189
oriented inclusions, and garnet from Obnazhennaya sample holds about 1 vol.% of them.
AC
CE P
TE
D
182
190
It is commonly observed that oriented inclusions are more or less uniformly distributed within
191
host garnets (Fig. 3 A–B). However, a large inclusion of phlogopite in garnet of Zarnitsa xenolith
192
was found to be surrounded by a halo of smaller faceted inclusions of quartz and apatite look like
193
the same as precipitates in garnet of this sample (Fig. 3 C–D). The typical feature of garnet
194
exsolution textures is to contain both monomineralic and polymineralic (or intergrown) lamellae.
195
Close up photos of several examples are shown in figure 4.
ACCEPTED MANUSCRIPT
9
Garnet porphyroblasts contain lamellae of rutile, quartz (and coesite), apatite, and ilmenite.
197
Light brown to yellowish in color rutile usually forms elongated needles or prisms 1–5 μm in
198
diameter and 10–200 μm long. It rarely has a bluish tint due to a strong interference color. Lamellae
199
of quartz, coesite and apatite are colorless. Quartz lamellae in garnet typically have more isometric
200
morphology, up to 5 μm in width and 30 μm in length, nevertheless long prisms of quartz were also
201
found (Fig. 4A). Coesite lamellae in garnet visually have no difference with quartz ones (Fig. 4B),
202
but coesite exsolutions are slightly smaller in size – no more than 20 μm long and 2-3 μm wide.
203
Apatite precipitates are characterized by prismatic morphology, up to 5 μm in width and 50 μm long
204
(Fig. 4 C–D). They differ from other colorless precipitates by a lower optical contrast. Ilmenite
205
forms no individual lamellae in garnets of studied samples, presenting only in intergrowths with
206
rutile precipitates. Most quartz and apatite precipitates are surrounded by tiny black or colorless
207
dots less than 1 μm in size, which likely represent the residues of decrepitated fluid inclusions.
TE
D
MA
NU
SC R
IP
T
196
CE P
208
4.1.2. Clinopyroxene host
210
Clinopyroxene occurs in form of large unaltered grains (up to 8mm long) or relics mounted into
211
pyroxene-feldspar symplectites. Both of them contain exsolution lamellae. Minerals exsolved from
212
clinopyroxene grains include rutile, apatite, ilmenite and orthopyroxene (only in Obnazhennaya
213
sample) (Fig. 5). They form: (i) thin elongated needles or plates from 0.5 to 10 μm wide and 50–
214
200 μm long; (ii) spindly oriented inclusions about 30–50 μm long and 3–10 μm thick; (iii)
215
thickened near-tabular plates up to 100 μm thick and several hundred microns long. The first type is
216
common for all the minerals composing lamellae in the clinopyroxenes, whereas the third one
217
corresponds only to the orthopyroxene lamellae in clinopyroxene of Obnazhennaya sample
218
(OLK1514). Udachnaya and Zarnitsa eclogitic clinopyroxenes generally contain about 0.9–1.9
219
vol.% of exsolution lamellae; clinopyroxene from the Obnazhennayaxenolith comprises almost 12
220
vol.% of exsolved minerals (Table 2).
AC
209
ACCEPTED MANUSCRIPT
10
Rutile lamellae forming needles, prisms or spindle-shaped grains up to 10 μm wide and 200 μm
222
long are brown in color, usually with a purple or green interference tint (Fig. 5A). Some of them
223
found in spongy-textured symplectites after clinopyroxene are with resorbed edges and surrounded
224
by ilmenite. Apatite exsolutions are presented as thin elongated needles (<1 μm wide and 10–25 μm
225
long) or plates (3–5 μm wide and up to 10 μm long) (Fig. 5 C–D). They form both individual and
226
intergrown lamellae. Ilmenite in clinopyroxenes has a minor distribution compared to other
227
exsolved minerals. It was identified only together with abundant rutile lamellae. Orthopyroxene
228
lamellae show morphologically various forms from small prism-like inclusions (2–5 μm wide and
229
20–50 μm long) to coarse well-defined extended plates up to 100 μm wide and several hundred
230
microns long (Fig. 5B). Orthopyroxene lamellae are usually intergrown with rutile ones.
MA
NU
SC R
IP
T
221
D
231
4.1.3. Kyanite host
233
Grospydite xenolith LUV134/10 contains kyanite crystals with rutile oriented inclusions occupying
234
about 0.2–0.4 % by volume. Rutile forms elongated needles with 2–4 μm thick and up to 200 μm
235
long (Fig. 6A).
CE P
AC
236
TE
232
237
4.2. Granular mineral inclusions
238
Contrary to UHP metamorphic rocks, which contain abundant single and multiphase mineral
239
inclusions, the rock-forming minerals are almost inclusions free, but in some case contain
240
inclusions of each other, testifying for their contemporary crystallization. Rounded and/or subhedral
241
granular SiO2 inclusions are more often included into garnet and kyanite grains in samples
242
LUV134/10 and UV58/10 from Udachnaya kimberlite. Being partially or slightly exposed, they
243
seem to be monocrystalline quartz with no evident palisade texture or polycrystalline shell. Larger
244
ones are frequently surrounded by medium to distinct radial crack patterns (Fig. 6B), whereas
245
smaller subhedral inclusions when unexposed demonstrate an obvious birefringent halo (Fig. 6C).
ACCEPTED MANUSCRIPT
11
246
4.3. Symplectite intergrowths
248
Xenoliths from Udachnaya kimberlite pipe include two types of symplectite (Table 1): 1) type I
249
represents subgraphic intergrowths of vermicular garnet and granular quartz aggregates with clear
250
outlines and whole size up to 10 mm (Fig. 7A); 2) type II looks like irregular aggregates composed
251
of feldspar and less sodic clinopyroxene (Cpx-2) (Fig. 7B), they are without abrupt margins, and a
252
grain size of composing minerals varies from the first microns to about 100 μm.
NU
SC R
IP
T
247
Coarse type I quartz-garnet symplectite was found in two Udachnaya xenoliths (UV662/11 and
254
LUV134/10). Type II feldspar-pyroxene symplectite replaces a part (samples UV662/11 and
255
UV58/10) or nearly all the clinopyroxene (sample LUV134/10). Feldspar from type II symplectite
256
belongs to plagioclase in xenoliths UV662/11 and LUV134/10, and to K-feldspar in UV58/10
257
eclogite. Both types of symplectite occur in quartz eclogites (Table 1).
TE
D
MA
253
CE P
258
5. Results
260
5.1. Major-element chemistry
261
5.1.1. Garnet composition
262
Garnets from studied xenoliths exhibit various composition range in Prp-Alm-Grs system (Fig. 8).
263
The end-member calculations were from Locock (2008). Two of studied xenoliths from Udachnaya
264
(LUV134/10 and UV662/11) contain pyrope-poor garnets (Prp<30) with Prp 13–19Alm24–41Grs35–59.
265
With respect to classification of Coleman et al. (1965), a pair of samples from Udachnaya and
266
Zarnitsa belongs to group B eclogites (UV58/10 and LUV184/10 respectively) having Prp31–
267
44Alm41–44Grs8–21,
268
eclogite (OLK1514) (Table 1). A wide range of garnet compositions is typical of mantle eclogites
269
worldwide (e.g. Aulbach et al., 2007; Caporuscio and Smyth, 1990; Hills and Haggerty, 1989;
270
Shervais et al., 1988; Sobolev, 1977; Taylor et al., 2003).
AC
259
and a single sample from Obnazhennaya with Prp62–63Alm25–26Grs6–7 is group A
ACCEPTED MANUSCRIPT
12
Individual garnet porphyroblasts are nearly homogeneous in their main components (Table 3);
272
the composition slightly varies in minor elements like Na, Ti, and P. In garnet composition the
273
interdependence between Na2O and TiO2+P2O5 and between Mg# {=100×Mg/(Mg+Fetotal)} and
274
TiO2+P2O5 was traced (Fig. 9). It sorts with the data from Koidu eclogitic garnets and from garnets
275
of other localities worldwide (Fung and Haggerty, 1995). The positive correlation between Na and
276
Ti (and P) contents in the garnets was also found in eclogites from Mir kimberlite (Yakutia, Russia)
277
(Beard et al., 1996). An excess Na content relative to Ti is considered to result from a substitution
278
of sixfold coordinated cations by Si (Beard et al., 1996), what was firstly supposed by Sobolev and
279
Lavrent'ev (1971).
MA
NU
SC R
IP
T
271
Eclogitic garnets containing apatite + rutile exsolution lamellae from Koidu kimberlite (Sierra
281
Leone; Fung and Haggerty, 1995) and Yangkou (Sulu terrane, China; Ye et al., 2000) have major-
282
element compositions akin to those for garnets with the same exsolution assemblage of this study
283
(Figs. 8 and 9). Composition of garnet containing rutile lamellae and quartz inclusions from
284
diamondiferous eclogite (Mir kimberlite pipe, Yakutia; Korsakov et al., 2009) resembles that of
285
studied grospydite xenolith LUV134/10 from Udachnaya. The composition of garnet with quartz
286
and rutile inclusions from sanidine-orthopyroxene eclogite of Zero kimberlite (South Africa;
287
Schmickler et al., 2004) is markedly close to that of garnet from studied Obnazhennaya
288
orthopyroxene-bearing eclogite OLK1514.
AC
CE P
TE
D
280
289
UHP crustal garnets including apatite precipitates like those from Kimi area, Rhodope, Greece
290
(Mposkos and Kostopoulos, 2001), from Ceuta, Northern Rif, Spain (Ruiz-Cruz and Sanz de
291
Galdeano 2013), Western New England, USA (Snoeyenbos and Koziol, 2008) and Australian
292
Bingara-Copeton alluvial garnets (Barron et al., 2005; not plotted on Fig. 8) have compositions
293
different from those in studied samples being richer in almandine and spessartine components (Fig.
294
8).
ACCEPTED MANUSCRIPT
13
Garnets from Udachnaya eclogites have higher TiO2 and Na2O (0.10–0.31 and 0.06–0.10 wt %,
296
respectively) contents as opposed to eclogites of Zarnitsa and Obnazhennaya, where TiO2 and Na2O
297
are 0.02–0.10 and 0.02–0.04 wt %, respectively. Low Na2O contents in garnet of OLK1514
298
correspond to data of Taylor et al. (2003) considering them as a typical feature of eclogites and
299
websterites from diamond-free Obnazhennaya kimberlite pipe. Na2O contents in garnets of studied
300
Udachnaya eclogite xenoliths fall into the range of those in the diamondiferous eclogites from the
301
same pipe (0.05–0.24 wt %; Sobolev and Lavrent’ev, 1971; Sobolev et al., 1994).
NU
SC R
IP
T
295
Using calculation scheme for garnet composition of Locock (2008), garnets from group C
303
eclogites UV662/11 and LUV134/10 contain up to 3 mol. % of majorite component (Table 3),
304
while Si contents lower 3.03 are considered as uncertainties within microprobe analyses.
MA
302
D
305
5.1.2. Clinopyroxene composition
307
Clinopyroxene compositions cover a wide range between omphacite and diopside (Fig. 10). On the
308
diagram of Essene and Fyfe (1967), they correspond to omphacite in Udachnaya xenoliths (Aug43–
309
67Jd31–53Aeg0–4)
310
11)
311
CaEs. The end-member calculations were from Katayama et al. (2000). Individual grains are
312
slightly inhomogeneous in major-element contents, especially in MgO and Al2O3 (Table 4). Using
313
scheme of Taylor and Neal (1989), clinopyroxene compositions of the sample UV58/10 lie in a
314
field of group C eclogites, and those of the UV662/11 belong to group B eclogites (Fig. 11). Garnet
315
compositions of these two samples demonstrate an inverse pertaining (Fig. 8).
CE P
TE
306
and to sodium-rich diopside-augites in samples from Zarnitsa (Aug72Jd15–16Aeg10–
AC
and Obnazhennaya (Aug73–75Jd21–22Aeg3–4) (Fig. 10), where Aug = Di + Hd + En + Fs + CaTs +
316
Composition of the clinopyroxenes containing apatite lamellae differs from that of eclogitic
317
clinopyroxene with the same lamellae from Koidu kimberlite (Fung and Haggerty, 1995) as shown
318
on figures 10 and 11. Clinopyroxene of the primary assemblage (cpx-1) in grospydite LUV134/10
319
exhibits concentrations of Ca-Eskola component as high as 6 mol. % opposed to other
ACCEPTED MANUSCRIPT
14
320
clinopyroxenes containing no Ca-Eskola molecule (Table 4). Primary clinopyroxenes of all studied
321
xenoliths contain Ca-Tschermak molecule, but the content ranges from 1 to 8 mol. % (Table 4). Secondary symplectitic clinopyroxenes have sodium-rich augitic composition with Aug77–93Jd2–
T
322 323
20Aeg0–4
324
mol.%) content compared to clinopyroxenes of primary assemblage (CaTs< 8 mol.%).
SC R
IP
(Table 4). A distinctive feature of these pyroxenes is relatively high Ca-Tschermak (10–16
325
6.1.3. Orthopyroxene composition
327
Orthopyroxene lamellae observed in clinopyroxene of OLK1514 have En85Fs14 and minor other
328
components (CaTs about 1 mol.%). Orthopyroxene contains about 0.7 wt % of Al2O3 and 0.22 wt
329
% of CaO (Table 4). The contents of CaO and Al2O3 are lower than those in orthopyroxenes from
330
group A eclogites from Obnazhennaya (Taylor et al., 2003) and comparable with orthopyroxene
331
compositions from Obnazhennaya websterite and clinopyroxenite xenoliths (Alifirova et al., 2012;
332
Taylor et al., 2003).
MA
D
TE
CE P
333
NU
326
6.1.4. Kyanite composition
335
Kyanite composition is characterized by SiO2 and Al2O3 contents 61.6 and 37.2 wt %, respectively.
336
Among the minor elements, Fe and Ti are found (FeOtotal about 0.3 wt % and TiO2 up to 0.06 wt
337
%), other elements are below the detection limit. Al2O3/SiO2 ratio is slightly lower than an ideal one
338
(1.65 versus 1.7). It is supposed to be reasonable (Pearson and Shaw, 1960) if the substitution of
339
small amounts of Fe, Ti, Mg and trace elements for Al is allowed.
AC
334
340 341
6.1.5. Rutile composition
342
Rutile composition has minor variations from sample to sample and among the different
343
morphologies (precipitates in garnet and clinopyroxene or individual grains). TiO2 ranges from 98.1
344
to 99.7wt % with slight amounts of FeO (0.29–0.67 wt %), CaO (up to 0.33 wt %) and Al2O3 (up
ACCEPTED MANUSCRIPT
15
0.23 wt %). Rutile lamellae in garnets from grospydite LUV134/10 contain ZrO2 as high as 0.20 wt
346
%, what is comparable with ZrO2 contents in rutiles from diamond inclusions (0.03–0.19 wt %;
347
Sobolev and Yefimova, 2000). Rutile composition is close to that in diamond-bearing eclogite from
348
Koidu kimberlite (Hills and Haggerty, 1989). Concentrations of Mg, Cr, and Nb oxides are below
349
the detection limit.
SC R
IP
T
345
350
6.1.6. Ilmenite composition
352
Ilmenite from studied Udachnaya and Zarnitsa eclogites is almost uniform in composition within
353
individual rock either in form of lamellae or separate grains and rims around rutile grains. It has
354
TiO2 52.00–56.10 wt % and FeO 39.35–44.62 wt %. Content of MgO is relatively low (<3.60 wt
355
%). Ilmenites contain MnO from 0.58 to 3.25 wt % and CaO no more than 0.73 wt %. According to
356
formula calculation, the ilmenites contain all iron in divalent form with no Fe3+. Compositions of
357
ilmenites lie into “non-kimberlitic” field according to Wyatt et al. (2004). However, statistically
358
kimberlitic ilmenites may also fall into this field (Wyatt et al., 2004).
MA
D
TE
CE P
359
NU
351
6.1.7. Feldspar composition
361
Feldspars composing in type II symplectites cover a range of anorthite-albite-orthoclase contents.
362
Plagioclase with An45–53Ab46–55 is observed in symplectites of xenoliths UV662/11 and
363
LUV134/10. Alkali feldspar with Or98Ab2 (orthoclase or sanidine) composes symplectites after
364
omphacitic clinopyroxene in sample UV58/10.
AC
360
365 366
5.2. Raman analyses
367
5.2.1. Oriented inclusions
368
All of studied samples except for grospydite LUV134/10 contain garnets with oriented quartz
369
inclusions (precipitates). Raman spectra of the precipitates demonstrate frequency shifts of normal
ACCEPTED MANUSCRIPT
16
α-quartz peaks; it is more obvious when the strongest quartz mode of 464 cm–1 is considered. The
371
highest shifts up to 476 cm–1 were fixed in small unexposed individual lamellae of quartz in garnets
372
of UV662/11 and UV58/10 (Fig. 12A). Slightly lower shifts up to 471 cm–1 were measured in the
373
same type of lamellae in the sample from OLK1514 (Obnazhennaya). The shift to no more than 466
374
cm–1 was obtained for quartz lamellae in garnets of Zarnitsa sample LUV184/10. For all the
375
samples, the following features were observed: 1) Raman shift is higher for smaller inclusions of
376
several microns wide; 2) exposed lamellae demonstrate lower values of the main quartz band shift;
377
3) discrete quartz lamellae have shifts higher than those in complex (intergrown with rutile or
378
apatite) ones; 4) inclusions surrounded by cracks have the lowest or no shifts of quartz bands.
MA
NU
SC R
IP
T
370
Coesite precipitates in garnet of UV662/11 were identified using Raman technique (Fig. 12B).
380
A typical coesite band of 521 cm–1 is shifted to 525 cm–1. At the other samples the coesite was not
381
found yet.
TE
D
379
Raman analysis was helpful in identification of minerals composing small colorless precipitates
383
in garnet and clinopyroxene hosts, especially in the case when they are not exposed. Apatite
384
lamellae were found in garnets of four samples from Udachnaya and Zarnitsa kimberlite pipes, and
385
in clinopyroxenes of three samples (UV662/11, UV134/10 and LUV184/10). Apatite spectra both in
386
garnet and clinopyroxene hosts demonstrate normal bands on 960–964 cm–1. According to EDS
387
data, apatites are likely to contain F together with minor Cl, S and OH–.
AC
CE P
382
388 389
5.2.2. Quartz granular inclusions and aggregates
390
Quartz inclusions in garnet and kyanite from two samples LUV134/10 and UV58/10 were studied.
391
Raman spectroscopic study reveals a common quartz band of 464 cm–1 for partially or slightly
392
exposed SiO2 inclusions in kyanite, and up to 466 cm–1 for them in garnet. Whereas an obvious
393
frequency shift of quartz band to 469 cm–1 in small uncovered SiO2 inclusions is observed.
394
Inclusions with crack patterns and large inclusions have lower or no frequency shifts, and those
ACCEPTED MANUSCRIPT
17
with birefringent halo demonstrate higher values for the common quartz band shift. Quartz grains
396
from type I symplectite and granular aggregate show a clear 464 cm–1 mode without any frequency
397
shift.
T
395
IP
398
5.3. Geothermobarometry
400
During several decades, the geothermobarometry for the rocks with eclogitic paragenesis remains as
401
a complex challenge. There is no universal way for the pressure-temperature calculation suitable for
402
all the known types of eclogites. In this paper we use different approaches for the P–T estimation
403
with respect to the type of each studied eclogite.
MA
NU
SC R
399
Temperature estimates for studied eclogite xenoliths were performed using garnet-
405
clinopyroxene Mg-Fe exchange reaction geothermometry of several calibrations (Ai, 1994; Ellis
406
and Green, 1979; Krogh, 1988; Krogh Ravna, 2000) (Fig. 13). To apply Fe–Mg exchange
407
geothermometry, the calculation of Fe3+ was assumed to be equal Na excess over Al + Cr for
408
clinopyroxenes. The ratios of Fe3+/Fetotal in studied garnets are low (0.04–0.06) according to charge
409
balance. The next step was to find the pressure on a geotherm that corresponds to the calculated
410
temperature (Table 5). The geotherm with a heat flow of 40 mW/m2 was taken, because of the best
411
suitability to the geothermal gradient of the lithospheric mantle under Udachnaya kimberlite pipe
412
(Boyd et al., 1997). Then, the average of estimated P–T parameters was counted. For the calculation
413
of average temperatures, the data obtained with the equation of Ai (1994) were excluded from the
414
computation due to their overstating. The average P–T values are represented in Table 5. According
415
to the calculations, studied eclogites from Udachnaya and Zarnitsa kimberlite pipes were
416
equilibrated at T=970–1080 °C and P=4.1–4.9 GPa. Obnazhennaya eclogite is likely to be
417
equilibrated at T=813 °C and P=3.2 GPa.
AC
CE P
TE
D
404
418
The eclogite xenolith from Obnazhennaya kimberlite pipe contains both orthorhombic and
419
monoclinic pyroxenes. Additionally, for this sample a Ca-in-orthopyroxene geothermometer in pair
ACCEPTED MANUSCRIPT
18
420
with garnet-orthopyroxene geobarometer was used (Brey and Kohler, 1990). Obtained P–T
421
estimates of 813 °C and 3.0 GPa are remarkably close to those computed by the former way. For the comparison with obtained data, the net transfer reactions geobarometry results according
423
to equations of Krogh Ravna and Terry (2004) were also shown on P–T plot (Fig. 13). Strictly
424
following to recommendations of Krogh Ravna and Terry (2004), it is better to use the equations for
425
the rocks with the full or minimally permissible mineral assemblage; otherwise the errors will be
426
great. Grospydite xenolith LUV134/10 from Udachnaya pipe fits to minimal criteria for the
427
evaluation. Using the geobarometer (equation 1 from the work of Krogh Ravna and Terry, 2004) in
428
combination with exchange thermometers discussed before the P–T parameters were calculated.
429
The average of them is comparable with that yielded by the firstly described method (Table 5).
MA
NU
SC R
IP
T
422
Transformation of the eclogites recorded in a presence of symplectites and exsolution textures
431
reveals the change of pressure and temperature parameters in the history of studied rocks. To
432
evaluate pressures of the type II symplectites formation, the clinopyroxene-feldspar geobarometer
433
was used (Holland, 1980). The geothermometer of Krogh Ravna (2000) was taken for the
434
combination. According to the calculations the type II symplectites were formed at 810–880 °C and
435
2.0–2.1 GPa in the quartz stability field. However, it should be noted, that symplectitic
436
clinopyroxenes are not in equilibrium with the garnet what is required when using classical
437
geothermometers.
AC
CE P
TE
D
430
438
Using the terminology of Joanny et al. (1991), studied type II feldspar-clinopyroxene
439
symplectites were preserved on globularization stage. The drop of pressure is responsible for the
440
globularization occurrence. Thus, the lamellar width is no more representative of temperature;
441
dependence on temperature according to the growth law during discontinuous precipitation is not
442
applicable (Joanny et al., 1991). However, we may estimate pressure at which type II symplectites
443
were stable. The jadeite contents ≤ 20 mol. % in secondary clinopyroxenes are attributed to those
444
less than 2.0 GPa (Gasparik and Lindsley, 1980). Symplectitic pyroxenes contain higher Ca-
ACCEPTED MANUSCRIPT
19
Tschermak content (>10 mol. %) compared to primary clinopyroxenes (CaTs < 8 mol. %).
446
According to the data for CMAS system (Gasparik, 2000) secondary pyroxenes should be stable at
447
pressures about 1.7–1.9 GPa at temperatures <1000 °C. It is more or less consistent with
448
thermobarometric results described before. Alternatively, pressures and temperatures were
449
estimated by applying clinopyroxene-2 compositions to the NCMAS dataset (Gasparik, 2014). The
450
contents of Ca, Al and Na in clinopyroxenes from type II symplectites suggest the temperatures and
451
pressures of about 1050–1070 °C and 2.6–3.0 GPa for the quartz eclogites from Udachnaya
452
(UV662/11 and UV58/10), and <800 °C and 1.6 GPa for the grospydite LUV134/10. Application of
453
data for NCMAS system (Gasparik, 2014) assumes slightly higher pressures and temperatures of
454
the type II symplectites formation, especially in quartz eclogites from Udachnaya.
MA
NU
SC R
IP
T
445
D
455
6. Discussion
457
6.1. Evolution of eclogite mantle xenoliths and constraints on their P–T history
CE P
TE
456
Mantle xenoliths in kimberlites worldwide are commonly presented by peridotites with fewer
459
amounts of other rock varieties including pyroxenites and eclogites (e.g. Dawson, 1980; Nixon and
460
Boyd, 1973). Nevertheless, several kimberlites contain eclogite nodules prevailing over other ones:
461
Zagadochnaya (Yakutia, Russia; Bobrievich et al., 1964; Sobolev et al., 1968); Roberts Victor and
462
Bobbejaan (South Africa; MacGregor and Carter, 1970; Smyth et al., 1984); Orapa (Botswana;
463
Shee and Gurney, 1979); Koidu (Sierra Leone; Hills and Haggerty, 1989). Taking into account the
464
common genetic links between mantle eclogites and diamonds, there is no doubt the significance of
465
a diversified examination of eclogites from different localities.
AC
458
466
The origin of the mantle eclogites is controversial (e.g. Jacob, 2004; Griffin and O’Reilly,
467
2007), with no exception for Yakutian ones (Sobolev et al., 1994; Snyder et al., 1997; Taylor et al.,
468
2003). The debates focused around two end-member hypotheses describing eclogite mantle
469
xenoliths as relics of subducted oceanic crust (“crustal” hypothesis; e.g. MacGregor and Manton,
ACCEPTED MANUSCRIPT
20
1986; Ireland et al., 1994; Jacob et al., 1994) or as products of high-pressure crystallization from
471
magmas with a purely mantle source (“mantle” hypothesis; e.g. Smyth et al., 1989; Caporuscio and
472
Smyth, 1990). In this contribution we lack stable isotope and trace element data in order to argue
473
the origin of eclogite xenoliths in Yakutian kimberlites either from crustal or mantle material.
474
However, several aspects regarding the origination and subsequent evolution of considered eclogitic
475
suite should be mentioned.
SC R
IP
T
470
Garnet grains of Udachnaya and Zarnitsa eclogites contain about 0.1 vol.% of apatite
477
precipitates, what corresponds to 0.09–0.12 wt % of P2O5 in recalculated garnet compositions and
478
to 0.06–0.07 wt % of P2O5 in whole-rock compositions. The value is comparable with an average
479
P2O5 content in the upper mantle (0.03–0.05 wt %) as estimated by Baker and Wyllie (1992) and is
480
lower than in N-MORB (0.17 wt %) (Sun and McDonough, 1989). To cover an entire budget of
481
P2O5 content in MORB, a free apatite is required in the rocks. However, apatite crystals are found to
482
be extremely rare in studied eclogites. Following the observations of Haggerty et al. (1994) and
483
experimental results of Watson (1980) the low whole-rock P2O5 contents in studied eclogites might
484
be explained by: 1) low P2O5 content in the eclogite protolith or source melt composition like
485
komatiites (about 0.08 wt % of P2O5) or melts formed in equilibrium with peridotite; 2)
486
redistribution of the phosphorus from mineral repository (garnet and clinopyroxene) to the
487
coexisting melt in accordance with the high compatible behavior of the P in the liquid; 3)
488
dissolution of the apatite during subsequent melting of the eclogites and extraction of the liquid
489
accompanied by a general decrease of phosphorus concentration in the rock.
AC
CE P
TE
D
MA
NU
476
490
With regard to other locations, eclogitic rocks containing garnets and clinopyroxenes with the
491
similar exsolution assemblages, as those from Koidu kimberlite (Sierra Leone; Haggerty et al.,
492
1994; Fung and Haggerty, 1995), are suggested to be of ‘mantle’ origin, whereas eclogites from
493
Yangkou (Sulu terrane, China; Ye et al., 2000) and Zero kimberlite (South Africa; Schmickler et al.,
494
2004) are considered to represent remnants of subducted oceanic crust. However, lately the origin
ACCEPTED MANUSCRIPT
21
of Koidu eclogitic xenoliths was reconsidered with respect to oxygen isotope and trace element data
496
(Barth et al., 2001, 2002). It was suggested that low-MgO eclogites (with the exsolutions like those
497
in Udachnaya and Zarnitsa samples) represent fragments of processed oceanic crust, subducted and
498
partially melted to produce TTG suites, i.e. they are related to residual eclogites, which were
499
subsequently emplaced into the lithospheric environment (Barth et al., 2001, 2002). Returning to
500
Udachnaya and Zarnitsa case, the protoliths of studied group B/C eclogites from these localities are
501
assumed to undergo nearly analogous geological processing during Archean-Proterozoic time
502
(Jacob and Foley, 1999) when the tectonic provinces of Siberian craton were formed (Rosen et al.,
503
2005) and intensive growth of the crust had taken place (Smelov et al., 2001; Shatsky et al., 2005).
504
In contrast, the protolith of the group A eclogite from Obnazhennaya kimberlite may have a hybrid
505
crust/mantle origin (Taylor et al., 2003) or originate from the lower cumulate parts of oceanic crust,
506
the subduction of which resulted to the formation of high-MgO metapyroxenitic (or metagabbroic)
507
eclogites (Barth et al., 2002). The latter case may well explain the formation and preservation of
508
exsolution textures of different scale in garnet (thin rutile + quartz needles) and clinopyroxene
509
(coarse orthopyroxene lamellae and thin rutile rods) hosts if the protolith of the eclogite was
510
subjected to long-term recycling and transformation long before the entrainment of the kimberlite.
AC
CE P
TE
D
MA
NU
SC R
IP
T
495
511
To constrain the subsolidus (or near-subsolidus) history of studied eclogites predating
512
exsolution processes, reconstructed major-element compositions of garnet and clinopyroxene have
513
been calculated (Table 6). Recalculated garnet compositions have higher TiO2 contents, ranging
514
from 0.74 to 1.18 wt % in Udachnaya and Zarnitsa eclogites and being equal to 0.37 wt % in
515
Obnazhennaya eclogite. Taking into account experimental data (e.g. Zhang et al., 2003) high
516
titanium contents in mantle garnets (so-called Ti-majoritic garnets) are indicative of their high-
517
temperature and high-pressure stability. It should be noted that reconstructed garnet compositions
518
are characterized by minor disproportion of tetravalent and divalent cations inconsistent with
519
classical majorite substitution. Thus, it may indicate a fundamentally different mechanism of cation
ACCEPTED MANUSCRIPT
22
substitution in the studied garnets involving coupled NaTiVI-R2+AlVI and NaPIV-R2+SiIV
521
substitutions (Na2CaTi2Si3O12, NaCa2(AlTi)Si3O12, Na3Al2P3O12, Na3Ti2(Si2P)O12) (Ringwood and
522
Major, 1971; Haggerty et al., 1994). To estimate the stability conditions of the studied high-Ti
523
garnets, the average majorite component XcatMj was calculated for reconstructed garnet
524
compositions using the equations suggested by Collerson et al. (2010) (Table 6). The Fe2+ and Fe3+
525
contents were treated in accordance with charge balance (Locock, 2008). The highest value XcatMj =
526
0.144 in the garnet of group C eclogite from Udachnaya (UV662/11) is observed. Reconstructed
527
garnet composition from grospydite LUV134/10 has XcatMj = 0.081, whereas those from group B
528
eclogites UV58/10 (Udachnaya) and LUV184/10 (Zarnitsa) exhibit XcatMj equal to 0.063 and 0.054
529
respectively. The value XcatMj in reconstructed garnet from Obnazhennaya is only 0.030. According
530
to empirical barometer for majoritic garnets (Collerson et al., 2010) calculated XcatMj values
531
coincide to 6.8–8.4 GPa for the Udachnaya and Zarnitsa eclogites and to 6.3 GPa for the
532
Obnazhennaya eclogite.
CE P
TE
D
MA
NU
SC R
IP
T
520
Considering substitutions of Si and Ti in garnets (and clinopyroxenes), it should take into
534
account that their solubility depends not only on pressure but on temperature too (e.g. Zhang et al.,
535
2003; Collerson et al., 2010). The temperatures of stability for precursor minerals should be high
536
enough to accommodate all the components that were decomposed during exsolution process.
537
Nonetheless, it is fairly difficult to estimate the contribution of temperature while using only
538
experimental data. However, the projection of our pressure estimates for reconstructed garnet
539
compositions to cratonic geotherm provides temperature values as high as 1300–1400 °C for
540
Udachnaya and Zarnitsa samples and about 1250 °C for Obnazhennaya eclogite (Fig. 14).
AC
533
541
Among the mantle silicates, garnet is considered to represent the major repository for
542
phosphorus (Hermann and Spandler, 2007; Thompson, 1975). Incorporation of P into garnet is
543
strongly coupled with Na substitution (Bishop et al., 1976; Haggerty et al., 1994; Reid et al., 1976).
544
Thus, the precipitation of apatite from garnet is predictable. In our case, the ratio of Na, P and Ti in
ACCEPTED MANUSCRIPT
23
garnets was considered in detail. As shown in figure 9, the contents of Na2O and TiO2+P2O5 of
546
garnets are in a positive correlation. It is consistent with natural data for mantle xenoliths.
547
Considering MORB system as a bulk composition closest to eclogitic rocks, it was shown
548
experimentally that with increasing temperature and/or pressure, the Ti+P and Na contents in garnet
549
still align to positive trend line, and the ratio (Ti+P):Na varies with changing bulk composition and
550
physical parameters (Konzett and Frost, 2009). The sample from Obnazhennaya kimberlite exhibits
551
Ti+P and Na contents in reconstructed garnets, that overlap experimental data from bulk
552
composition II (Mg-basalt) of Konzett and Frost (2009) and data points correspond to 850–1125°C
553
and 3–8 GPa. In reconstructed garnet compositions of Udachnaya and Zarnitsa xenoliths, the Ti+P
554
values correspond to data points for the experiments at 950–1200°C and 7–8 GPa from bulk
555
composition I (MORB) (Konzett and Frost, 2009). However, the Na contents in the reconstructed
556
garnets of Udachnaya and Zarnitsa samples are unusually low in respect to tetravalent cations.
557
When arguing the origin of these eclogites from relic oceanic crust (in particular, from MORB
558
source), the explanation of low Na2O contents in garnet is required. The one of the reasons is that
559
low Na versus (Ti+P) contents in garnet might result from presence of a fluid/melt in the system
560
prior to or during exsolution. The latter may correspond to a precipitation of minerals in an open
561
system (Proyer et al., 2013). Petrographic examination of the eclogites from Udachnaya and
562
Zarnitsa reveal the findings of textures (pockets with secondary minerals, spongy-textures
563
symplectites after primary clinopyroxene and kelyphitic rims around garnets) that are likely
564
attributed to metasomatic treatment and/or partial melting (Fung and Haggerty, 1995; Misra et al.,
565
2004; Sobolev et al., 1999; Spetsius and Taylor, 2002). Moreover, studied eclogites contain rare
566
accessory apatite, what may be caused by the dissolution of apatite during the infiltration of fluid or
567
melt extraction. Thus, the metasomatic overprinting to the eclogitic assemblage is not unreasonable.
568
Experimentally it was shown that phosphorus in silicates substitutes Si on T-sites with a strong
569
preference for isolated SiO4 tetrahedra in orthosilicates rather than linked tetrahedral in chain
AC
CE P
TE
D
MA
NU
SC R
IP
T
545
ACCEPTED MANUSCRIPT
24
silicates (e.g. Brunet and Chazot, 2001). However, some phosphorus content in clinopyroxenes is
571
detectable (Konzett and Frost, 2009). Apatite precipitation in primary clinopyroxenes from studied
572
eclogites allows us to declare original pyroxenes could have had no less than 0.05 wt% of P2O5.
573
Considering experimental data, precursor pyroxenes are believed to be stable at temperatures 900–
574
1200 °C and pressures about 4–8 GPa (bulk composition I+II; Konzett and Frost, 2009). Further
575
findings of apatite lamellae in similar eclogitic pyroxenes may serve as complementary indicator of
576
ultra-high pressure stage in rock history.
NU
SC R
IP
T
570
Petrographic study of garnet and kyanite grains reveals that granular quartz inclusions in them
578
are usually monocrystalline, and the small subhedral unexposed ones tend to be surrounded by an
579
obvious birefringent halo. As shown by Korsakov et al. (2009), these inclusions are indicative of
580
their high-pressure origin. Since Raman frequency shifts are considered to be dependent on pressure
581
and temperature, the data for the SiO2 polymorphs (Hemley, 1987) were used to calculate residual
582
pressure (Pi) in the quartz and coesite inclusions. The quartz inclusions retain the pressure as high
583
as 1.5–2.6 GPa in the samples UV662/11 and UV58/10, whereas in the sample OLK1514 Pi ranges
584
within 0.9–1.4 GPa, and the lowest Pi (0.5 GPa) is calculated in LUV184/10. Coesite inclusions in
585
UV662/11 show residual pressure up to 0.9–1.4 GPa.
AC
CE P
TE
D
MA
577
586
The symplectitic intergrowths found in Udachnaya eclogites provide additional information for
587
the subsolidus reactions in the rocks. Type II feldspar-clinopyroxene symplectites were found only
588
in quartz eclogites. This observation coincides to data of Enami and Zhang (1990) attributed their
589
formation to retrograde reaction between primary omphacitic clinopyroxene and quartz.
590
Thermobarometric results assume the formation of these symplectites at pressure interval
591
corresponding to quartz stability field. Data applied for NCMAS system (Gasparik, 2014) suggest
592
temperatures of the type II symplectites formation (about 1000 °C) as high as those
593
geothermobarometrically estimated for re-equilibrated garnet-clinopyroxene assemblage. These P–
ACCEPTED MANUSCRIPT
25
594
T parameters are suggestive of near-isothermal decompression of the rocks probably during the
595
kimberlite eruption. From the combination of considered aspects including mineral chemistry, petrography and
597
spectroscopic facts with respect to the results of experimental petrology, the P–T history shown in
598
figure 14 can be constructed. The eclogitic rocks from diamondiferous kimberlite pipes Udachnaya
599
and Zarnitsa are supposed to be derived from the depths 210–260 km (stage UZ I; Fig. 14) to the
600
levels about 130–150 km near the graphite-diamond equilibrium (Kennedy and Kennedy, 1976).
601
The eclogite from diamond-free Obnazhennaya kimberlite may be derived from the lower depth
602
(Ob I; Fig. 14). According to geothermobarometric calculations, studied eclogites from Udachnaya
603
and Zarnitsa were re-equilibrated at 970–1080 °C and 4.1–4.9 GPa (stage UZ II; Fig. 14). The
604
Obnazhennaya group A eclogite was equilibrated at about 813 °C and 3.0 GPa under significantly
605
lower P–T conditions (stage Ob II; Fig. 14). Symplectite formation (omphacite breakdown) in
606
Udachnaya eclogites within quartz stability field (60–65 km) is related to stage UZ III on figure 14.
607
Presumable pressure-temperature paths of studied eclogites are also depicted (Fig. 14). Constraints
608
on the P–T history show that the vertical displacement of the rocks from depths of up to 260 km
609
was not a momentary.
AC
CE P
TE
D
MA
NU
SC R
IP
T
596
610
6.2. Implications for geodynamic environment
611
In geodynamic context, considered transformation history of the eclogites and their protoliths is
612
likely attributed to the Precambrian time of cratonic amalgamation when several terranes were
613
accreted to each other, and, on one hand, the lithospheric keel of the Siberian craton was originated,
614
while, on other hand, the continental crust was formed and thickened (e.g. Smelov et al., 2001;
615
Rosen et al., 2005).
616
Geotectonically kimberlites of Daldyn (Udachnaya and Zarnitsa pipes) and Kuoika
617
(Obnazhennaya pipe) kimberlite fields are located within granite-greenstone terranes and near the
618
ancient suture zones, i.e. near the former convergent plate boundaries. The collision within Anabar
ACCEPTED MANUSCRIPT
26
tectonic province (including Daldyn and Markha terranes) (Rosen et al., 2007) may have displaced
620
protoliths of Udachnaya and Zarnitsa eclogites to the depth of 210–260 km at the stage UZ I of the
621
P–T history (Fig.14). Subsequent upwelling may have led to the uplift of the mantle portions to the
622
levels of 130–150 km, where the eclogites were re-equilibrated in accordance with the ambient
623
mantle conditions. Considering the case of Obnazhennaya sample, the subduction of the Aekit
624
orogen under Birekte terrane probably has moved mafic protolith of Obnazhennaya eclogite to the
625
depth of about 200 km (stage Ob I on Fig. 14). Further upwelling in the lithosphere under
626
Obnazhennaya kimberlite pipe resulted in an ascent of the eclogitic protolith from depths of about
627
200 km to the levels of 90–100 km indicated by the geothermobarometric estimates. The
628
transportation of the rocks was accompanied by the pressure-temperature drop what account for the
629
abundant exsolution textures observed in studied eclogites.
D
MA
NU
SC R
IP
T
619
The reconstructed mantle P–T paths of eclogitic protoliths with the proposed geodynamical
631
environment are more or less consistent with the geodynamic model 2 of Spengler et al. (2006), that
632
explains the occurrence of peridotites derived from the Mantle Transition Zone at Otrøy (western
633
Norway). This model supposes the majorite formation in subcontinental lithospheric mantle
634
(SCLM) after hot upwelling, deep melting and accretion in the Archaean, when part of the lower
635
lithosphere was subducted, or delaminated, sinking to the Mantle Transition Zone. After subsequent
636
thermal equilibration the peridotite residue became buoyant (e.g. Ringwood, 1994), rising in a
637
subsolidus upwelling to underplate existing SCLM in the mid-Proterozoic, accompanied by
638
majorite exsolution (Spengler et al., 2006). The emplacement of eclogites into SCLM may be
639
related to the direct adding of subducted ocean floor (Helmstedt and Gurney, 1995) to SCLM or to
640
the intrusion of magmas derived from more deeply-subducted protoliths (Griffin and O’Reilly,
641
2007).
AC
CE P
TE
630
642 643
7. Conclusions
ACCEPTED MANUSCRIPT
27
A number of P–T indicative textures are presented in the studied set of mantle eclogites from
645
Yakutian kimberlite pipes. The Udachnaya and Zarnitsa eclogitic rocks were derived firstly from
646
depths 210–260 km to the level 130–150 km near the graphite-diamond boundary, where the
647
eclogites were re-equilibrated with relation to heat flow corresponding to the lithospheric mantle of
648
the central part of Siberian craton. The following decompression and cooling likely results in the
649
formation of exsolution textures with rutile + apatite + coesite in garnet and clinopyroxene hosts.
650
The rocks were lately uplifted to depths 60–65 km, where nearly all coesite was transformed into
651
quartz retaining high-pressure origin. The feldspar-pyroxene symplectites after primary omphacitic
652
clinopyroxenes were formed. Eclogite from Obnazhennaya kimberlite is supposed to undergo
653
pressure-temperature decrease of smaller scale as compared to Udachnaya and Zarnitsa eclogites.
MA
NU
SC R
IP
T
644
D
654
Acknowledgements
656
The research was supported by Russian Foundation of Basic Research (grant Nos. 12-05-31411 and
657
12-05-00508), by the grant of President of Russia (MD-1260.2013.5) and by the Ministry of
658
education and science of Russian Federation (project No. 14.B25.31.0032). We are grateful to L.V.
659
Usova, V.N. Korolyuk, N.S. Karmanov, M.V. Khlestov, A.T. Titov, S.Z. Smirnov to their
660
assistance with analytical work and A.S. Alifirov to the comprehensive support in writing of the
661
paper. We would like to thank D. Spengler and I. Katayama for their constructive reviews and T.
662
Hirajima for valuable comments during the preparation of the paper.
AC
CE P
TE
655
663 664
References
665
Ague, J.J., Eckert, J.O. Jr., 2012. Precipitation of rutile and ilmenite needles in garnet: implications
666
for extreme metamorphic conditions in the Acadian Orogen, U.S.A. American Mineralogist 79,
667
840–855.
ACCEPTED MANUSCRIPT
668 669
28
Ai, Y., 1994. A revision of the garnet–clinopyroxene Fe2+ – Mg exchange geothermometer. Contributions to Mineralogy and Petrology 115, 467–473. Alifirova, T.A., Pokhilenko, L.N., Ovchinnikov, Y.I., Donnelly, C.L., Riches, A.J.V., Taylor, L.A.,
671
2012. Petrologic origin of exsolution textures in mantle minerals: evidence in pyroxenitic
672
xenoliths from Yakutia kimberlites. International Geology Review 54, 1071–1092.
675 676
IP
SC R
pyroxenites from the Central Slave Craton, Canada. Journal of Petrology 48, 1843–1873.
NU
674
Aulbach, S., Pearson, N.J., O’Reilly, S.Y., Doyle, B.J., 2007.Origins of xenolithic eclogites and
Baker, B.M., Wyllie, P.J., 1992. High-pressure apatite solubility in carbonate-rich liquids: Implications for mantle metasomatism. Geochimica et Cosmochimica Acta 56, 3409–3422.
MA
673
T
670
Barron, B.J., Barron, L.M., Duncan, G., 2005. Eclogitic and ultra high pressure crustal garnets and
678
their relationship to Phanerozoic subduction diamonds, Bingara area, New England Fold Belt,
679
Eastern Australia. Economic Geology 100, 1565–1582.
TE
D
677
Barth, M.G., Rudnick, R.L., Horn, I., McDonough, W.F., Spicuzza, M.J., Valley, J.W., Haggerty,
681
S.E., 2001. Geochemistry of xenolithic eclogites from West Africa, part I: A link between low
682
MgO eclogites and archean crust formation. Geochimica et Cosmochimica Acta 65, 1499–1527.
683
Barth, M.G., Rudnick, R.L., Horn, I., McDonough, W.F., Spicuzza, M.J., Valley, J.W., Haggerty,
684
S.E., 2002. Geochemistry of xenolithic eclogites from West Africa, part 2: origins of the high
685
MgO eclogites. Geochimica et Cosmochimica Acta 66, 4325–4345.
AC
CE P
680
686
Beard, B. L., Fraracci, K. N., Taylor, L. A., Snyder, G. A., Clayton, R. A., Mayeda, T. K., Sobolev,
687
N.V. 1996. Petrography and geochemistry of eclogites from the Mir kimberlite, Yakutia, Russia.
688
Contributions to Mineralogy and Petrology 125, 293–310.
689 690
Bishop, F. C., Smith, J. V., Dawson, J. B., 1976. Na, P, Ti and coordination of Si in garnet from peridotite and eclogite xenoliths. Nature 260, 696–697.
ACCEPTED MANUSCRIPT
29
Bobrievich, A.P., Ilupin, I.P., Kozlov, I.T., Lebedeva, L.I., Pankratov, A.A., Smirnov, G.I.,
692
Kharkiv, A.D., 1964. Petrography and Mineralogy of Kimberlitic Rocks of Yakutia, Nedra,
693
Moscow, 191 pp. (in Russian)
T
691
Bose, K., Ganguly, J., 1995. Quartz–coesite transition revisited: Reversed experimental
695
determination at 500-1200 °C and retrieved thermochemical properties. American Mineralogist
696
80, 231–238.
SC R
IP
694
Boyd, F.R., Pokhilenko, N.P., Pearson, D.G., Mertzman, S.A., Sobolev, N.V., Finger, L.W., 1997.
698
Composition of the Siberian cratonic mantle: evidence from Udachnaya peridotites xenoliths.
699
Contributions to Mineralogy and Petrology 128, 228–246.
MA
NU
697
Brey, G.P., Kohler, T., 1990.Geothermobarometry in four-phase lherzolites II: New
701
thermobarometers and practical assessment of existing thermobarometers. Journal of Petrology
702
31, 1353–1378.
705 706 707 708
TE
CE P
704
Brunet, F., Chazot, G., 2001.Partitioning of phosphorus between olivine, clinopyroxene and silicate glass in a spinel lherzolite xenolith from Yemen. Chemical Geology 176, 51–72. Caporuscio, F.A., Smyth, J.R., 1990. Trace element crystal chemistry of mantle eclogites. Contributions to Mineralogy and Petrology 105, 550–561.
AC
703
D
700
Coleman, R.G., Lee, D.E., Beatty, L.B., Brannock, W.W., 1965. Eclogites and eclogites: Their differences and similarities. Geological Society of America Bulletin, 76, 483–508.
709
Collerson, K.D., Williams, Q., Kamber, B.S., Omori, S., Arai, H., Ohtani, E., 2010.Majoritic
710
garnet: a new approach to pressure estimation of shock events in meteorites andthe encapsulation
711
of sub-lithospheric inclusions in diamond. Geochimica et Cosmochimica Acta 74, 5939–5957.
712
Davis, G.L., Sobolev, N.V., Khar’kiv, A.D., 1980. New data on the age of Yakutian kimberlites
713 714 715
obtained by the uranium-lead method on zircons. Doklady Earth Sciences 254, 53–57. Dawson, J.B., Smith, J.V., 1986. Relationships between eclogites and certain megacrysts from the Jagersfontein kimberlite, South Africa. Lithos 19, 325–330.
ACCEPTED MANUSCRIPT
30
Dawson, J.B., 1980. Kimberlites and their xenoliths. New York, Springer-Verlag.
717
Ellis, D.J., Green, D.H., 1979. An experimental study of the effect of Ca upon the garnet–
718
clinopyroxene Fe–Mg exchange equilibria. Contributions to Mineralogy and Petrology 71, 13–
719
22.
722 723
IP
SC R
721
Enami, M., Zhang, Q., 1990.Quartz pseudomorphs after coesite in eclogites from Shandong province, East China. American Mineralogist 75, 381–386.
Essene, E.J., Fyfe, W.S., 1967. Omphacite in California metamorphic rocks. Contributions to
NU
720
T
716
Mineralogy and Petrology 15, 1–23.
Fung, A.T., Haggerty, S.E., 1995. Petrography and mineral compositions of eclogites from the
725
Koidu Kimberlite Complex, Sierra Leone. Journal of Geophysical Research 100, 20451–20473.
726
Gasparik, T., 2000. An internally consistently thermodynamic model for the system CaO–MgO–
727
Al2O3–SiO2 derived primarily from phase equilibrium data. Journal of Geology 108, 103–119.
728
Gasparik, T., 2014. Phase diagrams for geoscientists. An atlas of the Earth’s interior. Second
D
TE
CE P
729
MA
724
edition. New York, Springer.
Gasparik, T., Lindsley, D.H., 1980. Phase equilibria at high pressure of pyroxenes containing
731
monovalent and trivalent ions. In: Prewitt CT (ed), Reviews in Mineralogy, 1, Pyroxenes.
732
Mineralogical Society of America, Washington DC, 309–339.
733 734 735 736
AC
730
Griffin, W.L., Jensen, B.B., Misra, S.N., 1971. Anomalously elongated rutile in eclogite-facies pyroxene and garnet. Norsk Geologisk Tidsskrift 51, 177–185. Griffin, W.L., O’Reilly, S.Y., 2007. Cratonic lithospheric mantle: is anything subducted?. Episodes 30, 43–53.
737
Gudfinnsson, G.H., Presnall, D.C., 1996. Melting relations of model lherzolite in the system CaO–
738
MgO–Al2O3–SiO2 at 2.4–3.4 GPa and the generation of komatiites. Journal of Geophysical
739
Research 101, 27701–27709.
ACCEPTED MANUSCRIPT
746 747 748 749 750 751 752 753
T
IP
SC R
745
Helmstedt, H.H., Gurney, J.J., 1995. Geotectonic controls of primary diamond deposits: implications for area selection. Journal of Geochemical Exploration 53, 125–144. Hemley, R.J., 1987. Pressure dependence of Raman spectra of SiO2 polymorphs: α-quartz, coesite,
NU
744
Roberts Victor kimberlite pipe, South Africa. Physics and Chemistry of the Earth 9, 367–387.
and stishovite. Terrapub. Tokyo-AGU, Washington, DC, 347–359. Hermann, J., Spandler, C.J., 2007. Sediment melts at sub-arc depth: an experimental study. Journal
MA
743
Harte, B., Gurney, J.J., 1975. Evolution of clinopyroxene and garnet in an eclogite nodule from the
of Petrology 49, 717–740.
Hills, D.V., Haggerty, S.E., 1989.Petrochemistry of eclogites from the Koidu Kimberlite Complex,
D
742
from the upper mantle. Geophysical Research Letters 21, 1699–1702.
Sierra Leone. Contributions to Mineralogy and Petrology 103, 397–422.
TE
741
Haggerty, S. E., Fung, A.T., Burt, D.M., 1994. Apatite, phosphorus and titanium in eclogitic garnet
Holland, T.J.B., 1980. The reaction albite=jadeite+quartz determined experimentally in the range
CE P
740
31
600–1200 °C. American Mineralogist 65, 129–134. Hwang, S.L., Yui, T.F., Chu, H.T., Shen, P., Schertl, H.P., Zhang, R.Y., Liou, J.G., 2007. On the
755
origin of oriented rutile needles in garnet from UHP eclogites. Journal of Metamorphic Geology
756
25, 349–362.
757 758
AC
754
Ireland, T.R., Rudnick, R.L., Spetsius, Z., 1994. Trace elements in diamond inclusions from eclogites reveal link to Archean granites. Earth and Planetary Science Letters 128, 199–213.
759
Jacob, D., Jagoutz, E., Lowry, D., Mattey, D., Kudrjavtseva, G., 1994. Diamondiferous eclogites
760
from Siberia: remnants of Archean oceanic crust. Geochimica et Cosmochimica Acta 58, 5191–
761
5207.
762
Jacob, D.E., 2004. Nature and origin of eclogite xenoliths from kimberlites. Lithos 77, 295–316.
763
Jacob, D.E., Foley, S.F., 1999. Evidence for Archean ocean crust with low high field strength
764
element signature from diamondiferous eclogite xenoliths. Lithos 48, 317–336.
ACCEPTED MANUSCRIPT
32
Jerde, E.A., Taylor, L.A., Crozaz, G., Sobolev, N.V., 1993. Exsolution of garnet within
766
clinopyroxene of mantle eclogites: major and trace element chemistry. Contributions to
767
Mineralogy and Petrology 114, 148–159.
IP
769
Joanny, V., van Roermund, H., Lardeaux, J.M., 1991. The clinopyroxene/plagioclase symplectite in retrograde eclogites: potential geothermobarometer. Geologische Rundschau 80, 303–320.
SC R
768
T
765
Katayama, I., Parkinson, C.D., Okamoto, K., Nakajima, Y., Maruyama, S., 2000. Supersilicic
771
clinopyroxene and silica exsolution in UHPM eclogite and pelitic gneiss from the Kokchetav
772
massif, Kazakhstan. American Mineralogist 85, 1368–1374.
774
Kennedy, C.S., Kennedy, G.C., 1976. The equilibrium boundary between graphite and
MA
773
NU
770
diamond.Journal of Geophysical Research 81, 2467–2470. Kinny, P.D., Griffin, B.J., Heaman, L.M., Brakhfogel, F.F., Spetsius, Z.V., 1997. SHRIMP U-Pb
776
ages of perovskite from Yakutian kimberlites. Proceedings of Sixth International Kimberlite
777
Conference, V. 1: Kimberlites, related rocks, and mantle xenoliths. Russian Geology and
778
Geophysics 38, 97–105.
TE
CE P
780
Kirkpatrick, R.J., 1977. Nucleation and growth of plagioclase, Makaopuhi and Alae lava lakes, Kilauea Volcano, Hawaii. Geological Society of America Bulletin 88, 78–84.
AC
779
D
775
781
Konzett, J., Frost, D.J., 2009. The high P–T stability of hydroxyl-apatite in natural andsimplified
782
MORB–an experimental study to 15 GPa with implications for transport andstorage of
783
phosphorus and halogens in subduction zones. Journal of Petrology 50, 2043–2062.
784
Korolyuk, V.N., Lavrent’ev, Yu G., Usova, L.V., Nigmatulina, E.N., 2008. JXA-8100
785
microanalyzer: Accuracy of analysis of rock-forming minerals. Russian Geology and Geophysics
786
49, 165–168.
787
Korsakov, A.V., Perraki, M., Zhukov, V.P., De Gussem, K., Vandenabeelee, P., Tomilenko, A.A.,
788
2009. Is quartz a potential indicator of ultrahigh-pressure metamorphism? Laser Raman
ACCEPTED MANUSCRIPT
33
789
spectroscopy of quartz inclusions in ultrahigh-pressure garnets. European Journal of Mineralogy
790
21, 1313–1323.
calibration. Journal of Metamorphic Geology 18, 211–219.
T
792
Krogh Ravna E., 2000. The garnet–clinopyroxene Fe2+– Mg geothermometer: an updated
IP
791
Krogh Ravna E., Terry, M.P., 2004. Geothermobarometry of UHP and HP eclogites and schists –
794
an evaluation of equilibria among garnet–clinopyroxene–kyanite–phengite–coesite/quartz.
795
Journal of Metamorphic Geology, 22, 579–592.
798 799
NU
existing experimental data. Contributions to Mineralogy and Petrology 99, 44–48.
MA
797
Krogh, E. J., 1988. The garnet–clinopyroxene Fe-Mg geothermometer – a reinterpretation of
Lavrent’ev, Yu. G., Usova, L.V., Kuznetsova, A.I., Letov, S.V., 1987. X-Ray spectral quantometric microanalysis of main kimberlite minerals. Soviet Geology and Geophysics 5, 53–58.
D
796
SC R
793
Locock, A., 2008. An Excel spreadsheet to recast analyses of garnet into end-member components,
801
and a synopsis of the crystal chemistry of natural silicate garnets. Computers and Geosciences 34,
802
1769–1780.
CE P
TE
800
MacGregor, I.D., Carter, J.L., 1970. The chemistry of clinopyroxenes and garnets of eclogite and
804
peridotite xenoliths from the Roberts Victor mine, South Africa. Physics of the Earth and
805
Planetary Interiors 3, 391–397.
806 807 808 809
AC
803
MacGregor, I.D., Manton, W.I., 1986. Roberts Victor eclogites: ancient oceanic crust. Journal of Geophysical Research 91, 14093–14079. McKenzie, D., Jackson, J., Priestley, K., 2005. Thermal structure of oceanic and continental lithosphere. Earth and Planetary Science Letters 233, 337– 49.
810
Misra, K., Anand, M., Taylor, L.A., Sobolev, N.V., 2004.Multi-stage metasomatism of
811
diamondiferous eclogite xenoliths from the Udachnaya kimberlite pipe, Yakutia, Siberia.
812
Contributions to Mineralogy and Petrology 146, 696-714.
ACCEPTED MANUSCRIPT
34
Mposkos, E.D., Kostopoulos, D.K., 2001. Diamond, former coesite and supersilicic garnet in
814
metasedimentary rocks from the Greek Rhodope: a new ultrahigh-pressure metamorphic province
815
established. Earth and Planetary Science Letters 192, 497–506.
820 821 822 823
IP
SC R
819
Patel, S.C., Ravi, S., Thakur, S.S., Rao, T.K., Subbarao, K.V., 2006.Eclogite xenoliths from Wajrakarur kimberlites, southern India. Mineralogy and Petrology 88, 363–380.
NU
818
In Lesotho Kimberlites (Nixon P.H., ed.). Lesotho National Development Corp., Maseru, 67–75.
Pearson, G.R., Shaw, D.M., 1960. Trace elements in kyanite, sillimanite and andalusite. American Mineralogist 45, 808–817.
MA
817
Nixon, P.H., Boyd, F.R., 1973. The discrete nodule association in kimberlites of northern Lesotho.
Pollack, H.N., Chapman, D.S., 1977.On the regional variation of heat flow, geotherms, and lithospheric thickness. Tectonophysics 38, 279–296.
D
816
T
813
Proyer, A., Habler, G., Abart, R., Wirth, R., Krenn, K., Hoinkes, G., 2013. TiO 2 exsolution from
825
garnet by open-system precipitation: evidence from crystallographic and shape preferred
826
orientation of rutile inclusions. Contributions to Mineralogy and Petrology 166, 211–234.
CE P
TE
824
Reid, A.M., Brown, R.W., Dawson, J.B., Whitfield, G.G., Siebert, J.C., 1976.Garnet and pyroxene
828
compositions in some diamondiferous eclogites. Contributions to Mineralogy and Petrology 58,
829
203–220.
830 831 832 833
AC
827
Ringwood, A. E, 1994. Role of the transition zone and 660 km discontinuity in mantle dynamics. Physics of the Earth and Planetary Interiors 86, 5–24. Ringwood, A.E., Major, A., 1971. Synthesis of majorite and other high pressure garnets and perovskites. Earth and Planetary Science Letters 12, 411–418.
834
Rosen, O.M., Manakov, A.V., Suvorov, V.D., 2005. The collisional system in the northeastern
835
Siberian Craton and a problem of diamond-bearing lithospheric keel. Geotectonics (English
836
Translation) 39, 456–479.
ACCEPTED MANUSCRIPT
35
Rosen, O.M., Levsky, L.K., Zhuravlev, D.Z., Spetsius, Z.V., Rotman, A.Y., Zinchouk, N.N.,
838
Manakov, A.V., Serenko, V.P., 2007. The Anabar collision system as an element of the
839
Columbia supercontinent: 600 Ma of compression (2.0–1.3 Ga). Doklady Earth Sciences 417,
840
1355–1358.
IP
T
837
Rosenthal, A., Yaxley, G.M., Green, D.H., Hermann, J., Kovacs, I., Spandler, C., 2014. Continuous
842
eclogite melting and variable refertilisation in upwelling heterogeneous mantle. Scientific
843
Reports 4, 6099.
NU
SC R
841
Ruiz-Cruz, M.D., Sanz de Galdeano, C., 2013 Coesite and diamond inclusions, exsolution
845
microstructures and chemical patterns in ultrahigh pressure garnet from Ceuta (Northern Rif,
846
Spain). Lithos 177, 184–206.
MA
844
Sautter, V., Harte, B., 1990. Diffusion gradients in an eclogite xenolith from the Roberts Victor
848
kimberlite pipe: (2) kinetics and implications for petrogenesis. Contributions to Mineralogy and
849
Petrology 105, 637–649.
CE P
TE
D
847
Schmickler, B., Jacob, D.E., Foley, S.F., 2004. Eclogite xenoliths from the Kuruman kimberlites,
851
South Africa: geochemical fingerprinting of deep subduction and cumulate processes. Lithos 75,
852
173–207.
AC
850
853
Shatsky, V.S., Buzlukova, L.V., Jagoutz, E., Koz'menko, O.A., Mityukhin, S.I., 2005. Structure and
854
evolution of the lower crust of the Daldyn-Alakit district in the Yakutian Diamond Province
855
(from data on xenoliths). Russian Geology and Geophysics 46, 1252–1270.
856
Shee, S.R., Gurney, J.J., 1979. The mineralogy of xenoliths from Orapa, Botswana, in: Boyd, F.R.,
857
Meyer, H.O.A. (Eds.), The mantle sample: Inclusions in kimberlites and other volcanics. American
858 859 860
Geophysical Union, Washington, D.C., pp. 37–49. Shervais, J.W., Taylor, L.A., Lugmair, G.W., Clayton, R.N., Mayeda, T.K., Korotev, R.L., 1988. Geological Society of America Bulletin 100, 411–423.
ACCEPTED MANUSCRIPT
36
Smelov, A.P., Gabyshev, V.D., Kovach V.P., Kotov, A.B., 2001. General structure of the basement
862
of the eastern part of the North Asian craton, in: Tectonics, geodynamics, and metallogeny of the
863
territory of the Sakha Republic (Yakutia), MAIK “Nauka/Interperiodika”, Moscow, pp. 108–112
864
[in Russian].
IP
T
861
Smith, D.C., 1988. A review of the peculiar mineralogy of the “Norwegian coesite-eclogite
866
province”, with crystal-chemical, petrological, geochemical and geodynamical notes and an
867
extensive bibliography, in: Smith, D.C. (Ed.), Eclogites and eclogite-facies rocks. Elsevier,
868
Amsterdam, pp. 1–206.
NU
SC R
865
Smyth, J.R., T.C., McCormick, T.C., Caporuscio F.A., 1984. Petrology of a suite of eclogite
870
inclusions from the Bobbejaan kimberlite, I. Two unusual corundum-bearing kyanite eclogites,
871
in: Kimberlites, II. The Mantle and Crust-Mantle Relationships, Elsevier, Amsterdam, pp. 109–
872
119.
TE
D
MA
869
Smyth, J.R., Caporuscio F.A., McCormick, T.C., 1989. Mantle eclogites, Udachnaya kimberlite
874
pipe, Yakutia, Siberia: evidence of differentiation in the early Earth?. Earth and Planetary
875
Science Letters 93, 133–141.
877 878 879 880 881 882 883 884 885
Snoeyenbos, D.R., Koziol, A.M., Exsolution phenomena of UHP type in garnets from Western New
AC
876
CE P
873
England, USA, 2008. American Geophysical Union, Abstract No.V31E-07. Snyder, G.A., Taylor, L.A., Crozaz, G., Halliday, A.N., Beard, B.L., Sobolev, V.N., Sobolev, N.V., 1997. The origins of Yakutian eclogite xenoliths. Journal of Petrology 38, 85–113. Sobolev, N.V., 1977. Deep-seated inclusions in kimberlites and the problem of the composition of the upper mantle. Publications of AGU, Washington, DC. Sobolev, N.V., Lavrent’ev, Y.G., 1971. Isomorphic sodium admixture in garnets formed at high pressures. Contributions to Mineralogy and Petrology 31, 1–12. Sobolev, N.V., Yefimova, E.S., 2000. Composition and petrogenesis of Ti-oxides associated with diamonds. International Geology Review 42, 758–767.
ACCEPTED MANUSCRIPT
888 889
the Zagadochnaya kimberlite pipe in Yakutia. Journal of Petrology 9, 253–280. Sobolev, V.N., Taylor, L.A., Snyder, G.A., Sobolev, N.V., 1994. Diamondiferous eclogites from
T
887
Sobolev, N.V., Kuznetsova, I.K., Zyuzin, N.I., 1968. The petrology of grospydite xenoliths from
Udachnaya kimberlite pipe, Yakutia. International Geology Review 36, 42–64.
IP
886
37
Sobolev, V.N., Taylor, L.A., Snyder, G.A., Jerde, E.A., Neal, C.R., Sobolev, N.V., 1999.
891
Quantifying the effects of metasomatism in mantle xenoliths: constraints from secondary
892
chemistry and mineralogy in Udachnaya eclogites, Yakutia. International Geology Review 41,
893
391–416.
NU
SC R
890
Spengler, D., van Roermund, H.L.M., Drury, M.R., Ottolini, L., Mason, P.R.D., Davies, G.R.,
895
2006. Deep origin and hot melting of an Archaean orogenic peridotite massif in Norway. Nature
896
440, 913–917.
899 900
D
TE
898
Spetsius, Z.V., Taylor, L.A., 2002. Partial melting in mantle eclogite xenoliths: connections with diamond paragenesis. International Geology Review 44, 973–987.
CE P
897
MA
894
Spetsius, Z.V., 2004. Petrology of highly aluminous xenoliths from kimberlites of Yakutia. Lithos 77, 525–538.
Sun, S.-s., McDonough, W.F., 1989. Chemical and isotopic systematic of oceanic basalts:
902
implications for mantle composition and processes, in: Sauders, A.D., Norry, M.J. (Eds.),
903
Magmatism in the Ocean Basins. Geological Society Special Publications, 42, pp. 313–345.
904 905
AC
901
Taylor, L.A., Anand, M., 2004. Diamonds: time capsules from the Siberian Mantle. Chemie der Erde Geochemistry 64, 1–74.
906
Taylor, L.A., Neal, C.R., 1989. Eclogites with oceanic crustal and mantle signatures from the
907
Bellsbank kimberlite, South Africa, Part I: Mineralogy, petrography, and whole rock chemistry.
908
Journal of Geology 97, 551–567.
ACCEPTED MANUSCRIPT
38
Taylor, L.A., Snyder, G.A., Keller, R., Remley, D.A., Anand, M., Wiesli, R., Valley, J., Sobolev,
910
N.V., 2003.Petrogenesis of group A eclogites and websterites: Evidence from the Obnazhennaya
911
kimberlite, Yakutia: Contributions to Mineralogy and Petrology 145, 424–443.
IP
913
Thompson, R.N., 1975. Is upper-mantle phosphorous contained in sodic garnet? Earth and Planetary Science Letters 26, 417-424.
SC R
912
T
909
Watson, E.B., 1980. Apatite and phosphorus in mantle source regions: an experimental study of
915
apatite/melt equilibria at pressures to 25kbar. Earth and Planetary Science Letters 51, 322–335.
916
Whitney, D.L., Evans, B.W., 2010. Abbreviations for names of rock-forming minerals. American
920 921
MA
and “non-kimberlitic” ilmenite. Lithos 77, 819-840.
D
919
Wyatt, B.A., Mike, B., Anckar, E., Grutter, H., 2004. Compositional classification of “kimberlitic”
Ye, K., Cong, B., Ye, D., 2000.The possible subduction of continental material to depths greater
TE
918
Mineralogist 95, 185–187.
than 200 km. Nature 407, 734–736.
CE P
917
NU
914
Zhang, R.Y., Zhai, S.M., Fei, Y.W., Liou, J.G., 2003. Titanium solubility in coexisting garnet and
923
clinopyroxene at very high pressure: the significance of exsolved rutile in garnet. Earth and
924
Planetary Science Letters 216, 591–601.
925
AC
922
ACCEPTED MANUSCRIPT
926
39
Figure captions
927
Fig. 1. Schematic map of the Siberian craton showing boundaries of the craton (1) and its terranes
929
(2), surface exposures of Precambrian rocks within Anabar shield (3), location of Mesozoic (4) and
930
Paleozoic (5) kimberlite fields. The locations of the Udachnaya, Zarnitsa and Obnazhennaya
931
kimberlite pipes (6), from which the studied xenoliths are derived, are also shown (modified after
932
Rosen et al., 2005 and Alifirova et al., 2012). The Anabar Province consists of the Daldyn, Markha
933
and Magan terranes, and the Olenyok Province consists of the Hapschan, Birekte and Aekit
934
terranes.
MA
NU
SC R
IP
T
928
935
Fig. 2. Petrographic features of quartz eclogites from Udachnaya. Primary garnet and clinopyroxene
937
(cpx-1) porhyroblasts surrounded by kelyphitic rims (Kel) and pyroxene-2 + feldspar symplectites
938
(Sym II), respectively, the irregular-shaped granular aggregates of quartz are shown with respect to
939
samples UV58/10 (A) and UV662/11 (B). Pockets with secondary minerals or melt pockets (MP; of
940
almost black color in pictures) are located both at grain boundaries and within quartz granular
941
aggregates.
TE
CE P
AC
942
D
936
943
Fig. 3. Scale and appearance of exsolution textures in garnets. A – quartz + rutile+apatite lamellae
944
in the garnet of eclogite LUV184/10 (Zarnitsa). B – precipitates of quartz and rutile in the garnet of
945
eclogite OLK1514 (Obnazhennaya). C and D – an aureole of small quartz and apatite oriented
946
inclusions surrounding phlogopite inclusion in the garnet of eclogite LUV184/10 (Zarnitsa).
947 948
Fig. 4. Precipitates in eclogitic garnet porhyroblasts. A – intergrown rutile and quartz lamellae in
949
the garnet of eclogite UV662/11 (Udachnaya). B – coesite lamella in the garnet of eclogite
950
UV662/11 (Udachnaya). C – intergrown apatite and rutile needles in a garnet of grospydite
ACCEPTED MANUSCRIPT
40
951
LUV134/10 (Udachnaya). D – intergrown quartz and apatite precipitates in a garnet of eclogite
952
LUV184/10 (Zarnitsa).
T
953
Fig. 5. Exsolution textures in clinopyroxenes. A – rutile + apatite lamellae hosted in clinopyroxene
955
of eclogite UV662/11 (Udachnaya). B – coarse orthopyroxene lamellae included into clinopyroxene
956
host from eclogite OLK1514 (Obnazhennaya). C – separate apatite and rutile in clinopyroxene of
957
eclogite UV662/11 (Udachnaya). D – intergrown apatite platelet and rutile inclusion in
958
clinopyroxene of eclogite LUV184/10 (Zarnitsa).
NU
SC R
IP
954
MA
959
Fig. 6. Inclusions in kyanite (A) and garnet (B, C) in studied eclogites. A – oriented rutile needles in
961
kyanite matrix in grospydite LUV134/10 (Udachnaya). B - large covered quartz inclusion with a
962
strong radial crack pattern around, eclogite UV58/10 (Udachnaya). C – quartz inclusion surrounded
963
by an optical halo, eclogite UV58/10 (Udachnaya).
TE
CE P
964
D
960
Fig. 7. BSE images showing two types of symplectites in the grospydite LUV134/10. A – large
966
subgraphic intergrowths of quartz and garnet. B –tiny clinopyroxene-plagioclase intergrowths after
967
sodic clinopyroxene surrounding resorbed rutile lamella with minor ilmenite.
AC
965
968 969
Fig. 8. Ternary diagram for garnet composition. Colored crosses indicate compositions from
970
eclogites of this study. Star – diamondiferous eclogite xenoliths from Mir kimberlite, Yakutia,
971
Russia (Korsakov et al., 2009), squares – low-MgO eclogitic xenoliths from Koidu kimberlite
972
complex, Africa (Fung and Haggerty, 1995), diamonds – eclogites from Yangkou, Sulu UHP
973
metamorphic belt, China (Ye et al., 2000), inverted triangle – sanidine-orthopyroxene eclogite from
974
Zero kimberlite, South Africa (Schmickler et al., 2004), circle – garnet-biotite-kyanite gneiss from
975
Kimi area, Rhodope, Greece (Mposkos and Kostopoulos, 2001), triangles – garnet-rich
ACCEPTED MANUSCRIPT
41
migmatitesfrom Ceuta, Northern Rif, Spain (Ruiz-Cruz and Sanz de Galdeano 2013). Dashed lines
977
divide eclogitic garnet compositions on A, B and C groups according to Coleman et al. (1965).
978
Shaded grey area shows variation of garnet composition in eclogite and grospydite xenoliths from
979
Yakutian kimberlites, data combined from Sobolev (1977), Sobolev et al. (1968; 1994), Beard et al.
980
(1996), Snyder et al. (1997), Taylor et al. (2003), Spetsius (2004).
SC R
IP
T
976
981
Fig. 9. Major-element composition of garnets from eclogites. Legend and references are the same as
983
on Fig. 8. Eclogitic garnets from Koidu kimberlite (West Africa) and from Yangkou (Sulu, China)
984
are shown for the comparison. Dotted lines round the points of the samples. The Mg# =
985
{Mg/(Mg+Fe)}×100.
MA
NU
982
D
986
Fig. 10. Ternary diagram for sodic clinopyroxene compositions. Colored crosses indicate
988
compositions from eclogites of this study. Square – low-MgO eclogitic xenolith from Koidu
989
kimberlite complex, Africa (Fung and Haggerty, 1995). Clinopyroxene from Koidu xenolith (KEC-
990
81-12) contains both rutile and apatite lamellae. Diagram subdivisions are after Essene and Fyfe
991
(1967). Aug = Di + Hd + En + Fs + CaTs + CaEs.
CE P
AC
992
TE
987
993
Fig. 11. Major-element compositional features of clinopyroxenes from eclogite xenoliths. Legend
994
and references are the same as on Fig. 10. Dashed lines divide eclogites of A, B and C groups
995
according to Taylor and Neal (1989). Shaded grey areas show variation of clinopyroxene
996
composition in eclogite and grospydite xenoliths from Yakutian kimberlites, data combined from
997
Sobolev (1977), Sobolev et al. (1968; 1994), Beard et al. (1996), Snyder et al. (1997), Taylor et al.
998
(2003), Spetsius (2004).
999
ACCEPTED MANUSCRIPT
42
Fig. 12. Representative Raman spectra of quartz (A) and coesite (B) lamellae in host garnet
1001
porphyroblasts of eclogite xenolith UV662/11. Characteristic modes of the quartz are typed by a
1002
violet font, modes of the coesite are light blue, and those of the host garnet are magenta.
T
1000
IP
1003
Fig. 13. Geothermobarometry results obtained for studied set of eclogitic xenoliths from Udachnaya
1005
(A-C), Zarnitsa (D) and Obnazhennaya (E). Abbreviations: K88 –geothermometer after Krogh
1006
(1988), EG79 –geothermometer after Ellis and Green (1979), KR00 –geothermometer after Krogh
1007
Ravna(2000),
1008
orthopyroxenegeobarometer after Brey and Kohler (1990), KRT04 – geobarometers according to
1009
equations (1)-(3) from Krogh Ravna and Terry (2004). Quartz-coesite equilibrium is after Bose and
1010
Ganguly(1995); graphite-diamond transition is according to Kennedy and Kennedy (1976).
1011
Continental geotherm of 40 mW/m2 heat flow is from Pollack and Chapman (1977).
–
two-pyroxene
geothermometer
in
combination
with
garnet-
TE
D
MA
BK90
NU
SC R
1004
CE P
1012
Fig. 14. P–T paths of Udachnaya and Zarnitsa (UZ; purple arrows and area) and Obnazhennaya
1014
(Ob; light blue arrows and area) eclogites. The stages I (semitransparent colored rectangles) are
1015
indicated for the presumable pressure-temperature parameters of pre-exsolution assemblage. The
1016
stages II (areas with double hatching) correspond to the geothermobarometric calculations. The
1017
stage III (hatched rectangle) marks the breakdown of omphacitic clinopyroxene and the formation
1018
of spongy-textured type II symplectites. Majorite stability field (dark grey gradient area) and phase
1019
relationships for the CMAS system were constructed from Gasparik (2014). The isentrope for TP =
1020
1315 °C is from McKenzie et al. (2005). The solidus of ‘dry’ (nominally anhydrous) coesite
1021
eclogite after extraction of potassic dacitic-rhyodacitic melt is according to Rosenthal et al. (2014).
1022
The curve labelled ‘Qz/Coe-out’ indicates the stability of quartz or coesite in eclogite below this
1023
curve. The solidus of ‘dry’ peridotite is based on Gudfinnsson and Presnall (1996). The quartz-
AC
1013
ACCEPTED MANUSCRIPT
43
1024
coesite (Bose and Ganguly, 1995) and graphite-diamond phase changes (Kennedy and Kennedy,
1025
1976) as well as continental geotherm (Pollack and Chapman, 1977) are also shown.
AC
CE P
TE
D
MA
NU
SC R
IP
T
1026
ACCEPTED MANUSCRIPT
1027
44
Table captions
1028
Table 1
1030
Summarized sample information on their locality, rock type and minerals in exsolution textures.
1031
Group subdivision is after Coleman et al. (1965). Mineral abbreviations here and below are after
1032
Whitney and Evans (2010).
SC R
IP
T
1029
NU
1033
Table 2
1035
Volumetric proportions (in vol.%) of exsolution features in silicate hosts of studied eclogitic
1036
xenoliths from Yakutian kimberlites.
D
1037
MA
1034
Table 3
1039
Average major-element compositions of garnets in eclogitic xenoliths from Udachnaya, Zarnitsa
1040
and Obnazhennaya kimberlite pipes.
1041
Note: CP – porphyroblast core, RP – rim of porphyroblasts, S – symplectitic grains, SG – small
1042
grains, CSG – core of small grains, RSG – rim of small grains, CS – core of symplectitic grains, RS
1043
– rim of symplectitic grains, NP – near phlogopite inclusion, NH – near halo of quartz-apatite
1044
inclusions.
1045
member calculations are from Locock (2008). Specific components: NaTi garnet (NaTi grt)
1046
Na2CaTi2Si3O12, Majorite (Maj) Mg3MgSiSi3O12.
1
AC
CE P
TE
1038
Total Fe as FeO. The number of analyses (N) is also shown. The cation and end-
1047 1048
Table 4
1049
Average major-element compositions of clinopyroxenes in eclogitic xenoliths from Udachnaya,
1050
Zarnitsa and Obnazhennaya kimberlite pipes.
ACCEPTED MANUSCRIPT
45
Note: CP – porphyroblast core, RP – rim of porphyroblasts, SII –grains in type II symplectites, OL
1052
– orthopyroxene lamellae. 1 Total Fe as FeO. The number of analyses (N) is also shown. The cation
1053
and end-member calculations are from Katayama et al. (2000). Specific component: NaTi pyroxene
1054
(NaTi cpx) Na(Mg,Fe)0.5Ti0.5Si2O6.
IP
T
1051
SC R
1055
Table 5
1057
Pressure-temperature estimates for the studied mantle xenoliths. Temperatures are in °C and
1058
pressures are in GPa.
1059
Note: TK88 –garnet-clinopyroxene geothermometer after Krogh (1988), TEG79 – garnet-
1060
clinopyroxene geothermometer after Ellis and Green (1979), TKR00 – garnet-clinopyroxene
1061
geothermometer after Krogh Ravna(2000), TBK90 – single orthopyroxene geothermometer (Brey and
1062
Kohler, 1990), PBK90 – garnet-orthopyroxene geobarometer (Brey and Kohler, 1990), PKRT04-1 –
1063
pressure estimation according to equation (1) from Krogh Ravna and Terry (2004), Pg40 – pressure
1064
estimation in intersection of temperature line with geotherm 40 mW/m2 (Pollack and Chapman,
1065
1977), Tav – average of TK88, TEG79 and TKR00, Pav – average of pressure estimations without PBK90.
1066
AC
CE P
TE
D
MA
NU
1056
1067
Table 6
1068
Reconstructed mineral major-element (wt%) compositions.
1069
Note:
1070
Collerson et al. (2010). The cation and end-member calculations are from Locock (2008) for garnet
1071
and from Katayama et al. (2000) for clinopyroxene. Specific components: Schorlomite-Al
1072
Ca3Ti2SiAl2O12, Morimotoite Ca3TiFe2+Si3O12, NaTi garnet (NaTi grt) Na2CaTi2Si3O12,
1073
Morimotoite-Mg Ca3TiMgSi3O12, NaTi pyroxene (NaTi cpx) Na(Mg,Fe)0.5Ti0.5Si2O6.
1074
1
Total Fe as FeO. The XcatMj in garnet were calculated in accordance with equations from
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
Figure 1
TE
1076
D
1075
AC
CE P
1077
46
SC R
IP
T
ACCEPTED MANUSCRIPT
1079
NU
1078
Figure 2
AC
CE P
TE
D
MA
1080
47
1082 1083
Figure 3
AC
1081
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
48
1085 1086
Figure 4
AC
1084
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
49
1088 1089
Figure 5
AC
1087
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
50
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
1090 1091 1092
Figure 6
51
1094 1095
Figure 7
AC
1093
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
52
1096 1097 1098
Figure 8
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
53
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
1099 1100 1101
Figure 9
54
1102 1103 1104
Figure 10
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
55
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
1105 1106 1107
Figure 11
56
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
1108 1109 1110
Figure 12
57
ACCEPTED MANUSCRIPT
AC
CE P
TE
D
MA
NU
SC R
IP
T
1111
1112 1113 1114
Figure 13
58
1115 1116 1117
Figure 14
AC
CE P
TE
D
MA
NU
SC R
IP
T
ACCEPTED MANUSCRIPT
59
ACCEPTED MANUSCRIPT
1118
60
Table 1 Host mineral Group
Symplectite Grt
Cpx
Ky
T
Rock type
Udachnaya-East
Quartz eclogite
C
Qz, Rt, Coe, Ap
Rt, Ap
–
I, II
UV58/10
Udachnaya-East
Quartz eclogite
B
Rt, Qz, Ap, Ilm
Rt, Ilm
–
II
LUV134/10
Udachnaya-East
Grospydite
C
Rt, Ap
Rt, Ilm, Ap
Rt
I, II
B
Qz, Rt, Ap, Ilm
Rt, Ap, Ilm
–
–
Qz, Rt
Opx, Rt
–
–
LUV184/10
Zarnitsa
OLK1514
Obnazhennaya
MA
Bimineralic eclogite
Orthopyroxene eclogite
D
1119
TE
1120
AC
CE P
1121
A
IP
UV662/11
SC R
Kimberlite
NU
Sample
ACCEPTED MANUSCRIPT
1122
61
Table 2 Grt
Cpx
Ky
Sample Coe
Ap
Ilm
Rt
Ap
Ilm
UV662/11
0.8
1.1
0.1
0.1
–
1.8
0.1
–
UV58/10
0.6
0.3
–
0.1
<0.1
0.8
–
LUV134/10
0.6
–
–
0.1
–
1.0
LUV184/10
0.6
0.7
–
0.1
<0.1
0.7
OLK1514
0.3
0.5
–
–
–
0.4
AC
CE P
TE
D
MA
1124
SC R
0.1
Rt
–
–
–
–
0.1
0.1
–
0.3
0.1
0.1
–
–
–
–
11.5
–
NU
1123
Opx
T
Qz
IP
Rt
ACCEPTED MANUSCRIPT
Table 3 UV662/11
1127
RS G N= 3 39. 94 0.2 2 21. 71 <0. 06 11. 82 0.1 6 4.2 9 21. 53 0.1 2 0.1 0 99. 80
3.0 28 0.0 14 1.9 37 <0. 004 0.7 26 0.0 48 0.0 10 0.4 66 1.7 51 0.0 14 0.0 05 8.0 01
3.0 25 0.0 15 1.9 45 <0. 004 0.7 33 0.0 39 0.0 12 0.4 56 1.7 54 0.0 11 0.0 05 7.9 97
3.0 20 0.0 13 1.9 44 <0. 004 0.7 25 0.0 42 0.0 10 0.4 75 1.7 60 0.0 10 0.0 05 8.0 05
SG
NP
NH
CP
RP
SG
CP
RP
N= N= N= N= 6 6 3 4 39. 39. 39. 39. SiO2 13 39 13 11 0.3 0.2 0.2 0.1 TiO2 1 6 2 4 Al2 20. 21. 21. 21. O3 86 01 05 28 Cr2 0.0 0.0 0.0 <0. O3 6 6 6 06 FeO 19. 19. 19. 20. 1 38 45 52 63 Mn 0.4 0.4 0.4 0.4 O 8 9 9 2 Mg 5.5 5.5 5.5 8.5 O 9 3 8 5 13. 13. 13. 8.9 CaO 63 58 51 3 Na2 0.1 0.0 0.0 0.0 O 0 8 7 8 0.0 0.0 0.0 0.0 P2O5 8 7 7 8 Tota 99. 99. 99. 99. l 64 93 69 24 Calculation on 12 Oxygen
N= 4 38. 95 0.1 0 21. 21 <0. 06 20. 62 0.4 1 8.6 8 8.9 0 0.0 6 0.0 6 99. 02
N= 3 39. 12 0.1 3 21. 22 <0. 06 21. 08 0.4 2 8.2 7 9.1 5 0.0 6 0.0 4 99. 52
N= 8 39. 30 0.1 0 21. 35 <0. 06 22. 33 0.4 8 11. 14 4.9 7 0.0 4 0.0 6 99. 82
N= 10 39. 31 0.0 6 21. 52 <0. 06 22. 18 0.4 8 11. 19 4.9 1 0.0 4 0.0 8 99. 80
N= 3 39. 10 0.0 7 21. 50 <0. 06 22. 73 0.4 7 10. 84 4.7 2 0.0 4 0.0 5 99. 55
N= 3 39. 39 0.0 4 21. 68 <0. 06 22. 05 0.4 6 11. 62 4.4 0 0.0 3 0.0 7 99. 78
N= 3 39. 34 0.0 9 21. 32 <0. 06 22. 20 0.4 9 11. 15 4.9 6 0.0 4 0.0 6 99. 68
N= 4 41. 17 0.0 4 22. 61 0.2 0 14. 15 0.3 5 17. 56 3.8 6 <0. 03 <0. 04 99. 97
N= 4 41. 07 0.0 4 22. 53 0.1 8 14. 25 0.3 5 17. 57 3.8 5 <0. 03 <0. 04 99. 86
N= 3 41. 18 <0. 04 22. 76 0.1 7 14. 49 0.3 6 17. 35 3.7 7 0.0 3 <0. 04 100 .11
N= 4 39. 85 0.2 5 21. 63 <0. 06 12. 18 0.1 6 4.1 2 21. 52 0.1 0 0.0 8 99. 82
3.0 20 0.0 Ti 18 1.8 Al 97 0.0 Cr 04 1.1 Fe2+ 70 0.0 Fe3+ 81 0.0 Mn 32 0.6 Mg 43 1.1 Ca 27 0.0 Na 16 0.0 P 05 Tota 8.0 l 12 End-members
3.0 00 0.0 06 1.9 25 <0. 004 1.2 60 0.0 68 0.0 27 0.9 95 0.7 34 0.0 09 0.0 04 8.0 30
3.0 04 0.0 08 1.9 21 <0. 004 1.2 84 0.0 69 0.0 27 0.9 46 0.7 53 0.0 09 0.0 03 8.0 26
2.9 90 0.0 06 1.9 15 <0. 004 1.3 44 0.0 77 0.0 31 1.2 63 0.4 05 0.0 06 0.0 04 8.0 43
2.9 86 0.0 02 1.9 37 <0. 004 1.3 40 0.0 58 0.0 30 1.3 13 0.3 57 0.0 05 0.0 05 8.0 36
2.9 95 0.0 05 1.9 13 <0. 004 1.3 34 0.0 79 0.0 32 1.2 64 0.4 05 0.0 06 0.0 04 8.0 39
2.9 93 0.0 02 1.9 37 0.0 11 0.8 10 0.0 49 0.0 22 1.9 02 0.3 01 <0. 004 <0. 003 8.0 31
2.9 91 0.0 02 1.9 33 0.0 10 0.8 13 0.0 54 0.0 22 1.9 06 0.3 00 <0. 004 <0. 003 8.0 35
2.9 91 <0. 002 1.9 49 0.0 10 0.8 39 0.0 41 0.0 22 1.8 78 0.2 93 0.0 04 <0. 003 8.0 28
3.0 04 0.0 08 1.9 26 <0. 004 1.2 61 0.0 64 0.0 27 0.9 79 0.7 35 0.0 11 0.0 05 8.0 22
2.9 87 0.0 03 1.9 27 <0. 004 1.3 43 0.0 67 0.0 31 1.2 67 0.4 00 0.0 06 0.0 05 8.0 39
2.9 87 0.0 04 1.9 35 <0. 004 1.3 93 0.0 59 0.0 30 1.2 33 0.3 86 0.0 05 0.0 03 8.0 39
IP
SC R
NU
MA
D
3.0 18 0.0 13 1.9 13 0.0 04 1.1 88 0.0 71 0.0 32 0.6 41 1.1 16 0.0 10 0.0 04 8.0 10
T
RP
CS
RS
N= 3 39. 86 0.2 2 21. 73 <0. 06 11. 53 0.1 4 4.3 1 21. 87 0.0 9 0.0 7 99. 77
N= 3 39. 94 0.2 1 21. 69 <0. 06 11. 51 0.1 4 4.2 8 21. 83 0.0 7 0.0 5 99. 65
3.0 30 0.0 12 1.9 41 <0. 004 0.7 04 0.0 46 0.0 10 0.4 84 1.7 49 0.0 17 0.0 06 8.0 02
3.0 24 0.0 13 1.9 43 <0. 004 0.6 87 0.0 44 0.0 09 0.4 87 1.7 77 0.0 14 0.0 05 8.0 04
3.0 31 0.0 12 1.9 40 <0. 004 0.6 84 0.0 47 0.0 09 0.4 84 1.7 75 0.0 05 0.0 03 7.9 92
NaT i grt
1
1
1
1
1
1
1
1
1
Maj
2
3
2
3
1
2
2
2
1
1
1
1
Sps
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Prp
19
17
19
33
33
31
42
42
41
44
42
63
63
62
13
14
13
14
14
15
Alm
40
41
40
41
41
42
43
43
44
42
43
25
25
26
26
26
25
25
24
24
Grs
35
36
35
21
21
21
8
9
9
8
9
6
6
7
57
57
58
57
59
58
Adr Othe r
2
1
2
3
3
4
5
4
4
4
4
3
3
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Uv
1126
N= 4 39. 87 0.2 6 21. 76 <0. 06 12. 17 0.1 8 4.0 4 21. 58 0.0 8 0.0 7 99. 96
CS G N= 3 39. 88 0.2 3 21. 79 <0. 06 12. 11 0.1 6 4.2 1 21. 69 0.0 7 0.0 7 100 .16
CP
TE
CP
LUV134/10
SG
3.0 28 0.0 15 1.9 04 0.0 04 1.1 73 0.0 77 0.0 32 0.6 34 1.1 19 0.0 11 0.0 05 8.0 02
S
OLK1514
RP
Si
RP
LUV184/10
AC
CP
UV58/10
CE P
1125
62
1
ACCEPTED MANUSCRIPT
Table 4 LUV134/10
UV58/10
LUV184/10
UV662/11
OLK1514
RP
SII
CP
RP
SII
CP
RP
CP
RP
SII
CP
RP
OL
SiO2
N=3 55.0 5
N=3 55.0 1
N=3 51.7 9
N=4 56.1 0
N=4 56.2 9
N=3 51.7 3
N=3 53.3 7
N=3 53.4 9
N=4 54.5 8
N=4 54.6 3
N=4 49.8 9
N=3 55.2 9
N=3 55.5 1
TiO2
0.32
0.30
0.20
0.21
0.24
0.38
0.56
0.51
0.22
0.26
0.39
0.15
0.13
N=4 56.9 1 <0.0 4
16.0 5 <0.0 6
11.3 9 <0.0 6
13.7 7 <0.0 6
13.2 7 <0.0 6
7.54
6.41
5.95
5.29
0.69
Cr2O3
16.0 4 <0.0 6
<0.0 6
0.10
0.20
0.23
<0.0 6
FeO1
2.76
2.80
3.27
4.13
4.06
6.21
7.52
3.10
2.93
9.35
MnO
<0.0 6
<0.0 6
<0.0 6
<0.0 6
MgO
6.42
6.33
<0.0 6 11.2 3 19.4 8 3.19 <0.0 3 100. 55
6.68
6.96
10.9 1 8.29 <0.0 3 100. 18
11.0 6 8.25 <0.0 3 100. 24
<0.0 6 12.3 9 18.3 2 1.94 <0.0 3 98.5 1
<0.0 6 13.4 7 17.9 4 3.87 <0.0 3 100. 03
<0.0 6 13.9 8 18.5 0 3.54 <0.0 3 100. 15
0.06 <0.0 3 99.8 5
1.85 6 0.00 5 0.48 1 <0.0 02 0.07 4 0.02 4 <0.0 02 0.60 0 0.74 8 0.22 2 <0.0 01 4.00 9
1.97 9 0.00 5 0.57 3 <0.0 02 0.09 2 0.02 9 <0.0 02 0.35 1 0.41 2 0.56 7 <0.0 01 4.01 2
1.98 5 0.00 6 0.55 2 <0.0 02 0.08 6 0.03 3 <0.0 02 0.36 6 0.41 8 0.56 4 <0.0 01 4.01 4
CE P
IP
9.16
8.64
6.56
0.09
<0.0 6
<0.0 6
7.25
5.26
5.17
NU
SC R 6.12
<0.0 6 10.0 3
<0.0 6
<0.0 6
0.07
11.0 7 17.5 4 3.96 <0.0 3 100. 60
11.6 8 17.3 9 4.03 <0.0 3 100. 62
9.37
9.92
16.0 8 5.17 <0.0 3 99.9 6
16.3 7 4.70
99.8 0
12.0 9 19.1 2 1.09 <0.0 3 99.4 17
1.91 0 0.01 1 0.32 8 <0.0 02 0.19 2 0.00 0 <0.0 02 0.68 2 0.72 5 0.13 9 <0.0 01 3.98 5
1.94 7 0.01 5 0.27 5 0.00 3 0.13 6 0.09 3 0.00 2 0.60 2 0.68 5 0.28 0 <0.0 01 4.03 9
1.94 8 0.01 4 0.26 3 0.00 3 0.11 2 0.10 9 0.00 2 0.63 4 0.67 9 0.28 4 <0.0 01 4.04 7
1.96 8 0.00 6 0.38 9 <0.0 02 0.13 0 0.02 8 <0.0 02 0.50 4 0.62 1 0.36 1 <0.0 01 4.01 1
1.97 2 0.00 7 0.36 7 <0.0 02 0.14 7 0.00 9 <0.0 02 0.53 3 0.63 3 0.32 9 0.00 1 4.00 1
1.86 9 0.01 1 0.29 0 <0.0 02 0.27 6 0.03 8 0.00 6 0.67 5 0.76 7 0.07 9 <0.0 01 4.01 4
1.98 4 0.00 4 0.25 2 0.00 6 0.05 2 0.04 1 <0.0 02 0.72 0 0.68 9 0.26 9 <0.0 01 4.01 8
1.99 0 0.00 3 0.22 3 0.00 6 0.05 4 0.03 4 <0.0 02 0.74 6 0.71 0 0.24 6 <0.0 01 4.01 5
1.98 9 <0.0 01 0.02 9 <0.0 02 0.27 3 0.00 0 0.00 3 1.69 1 0.00 8 0.00 4 <0.0 01 3.99 8
MA
0.07
D
12.9 13.0 8 7 Na2O 6.94 6.91 <0.0 <0.0 K2O 3 3 100. 100. Total 57 51 Calculation on 6 Oxygen 1.92 1.92 Si 6 6 0.00 0.00 Ti 8 8 0.66 0.66 Al 1 2 <0.0 <0.0 Cr 02 02 0.08 0.08 2+ Fe 1 2 0.00 0.00 3+ Fe 0 0 <0.0 <0.0 Mn 02 02 0.33 0.33 Mg 5 0 0.48 0.49 Ca 7 0 0.47 0.46 Na 1 9 <0.0 <0.0 K 01 01 3.97 3.96 Total 0 9 End-members CaO
TE
Al2O3
T
CP
AC
1128
63
0.03
0.20
0.09 32.4 7 0.22
CaEs
6
6
1
0
0
3
1
1
0
0
1
0
0
0
CaTs
8
8
16
2
2
10
5
5
3
3
14
1
1
1
48
47
20
53
52
12
16
15
33
31
2
22
21
0
0
0
2
4
3
0
10
11
3
1
4
4
3
0
32
33
49
37
39
56
58
58
56
59
54
66
69
0
Jd Aeg Di+Hd
ACCEPTED MANUSCRIPT
64
En+Fs NaTi cpx
5
5
11
3
3
18
8
8
4
5
24
6
5
99
1
1
1
1
1
1
2
2
1
1
1
0
0
0
Kos
0
0
0
0
0
0
0
0
0
0
0
1
1
0
AC
CE P
TE
D
MA
NU
SC R
IP
T
1129
ACCEPTED MANUSCRIPT
65
1130
Table 5 T K88 / P g40
T EG79 / P g40
T KR00 / P g40
T BK90 / P BK90
UV662/11
948
969
994
–
4.0
4.1
4.3
1032
1036
1147
4.6
4.6
5.4
966
1143
1104
4.1
5.4
5.1
961
1048
1230
4.1
4.7
779
913
3.1
3.8
LUV134/10
982
1133
(P KRT04-1)
4.6
5.0
1132 1133 1134
IP
SC R
NU
MA
OLK1514
–
–
970 4.1 1071 4.9 1071 4.9
–
6.1
D
LUV184/10
TE
LUV134/10
CE P
UV58/10
T av / P av
T
Sample No.
AC
1131
1080 4.9
749
813
813
2.9
3.0
3.2
1096
–
1070
4.9
4.9
ACCEPTED MANUSCRIPT
Table 6 LUV18 4/10
OLK1 514
LUV13 4/10
SiO2
39.30
38.96
39.33
41.26
39.55
TiO2
1.18
Al2O3
20.47
21.08
21.09
22.45
21.47
Cr2O3
0.06
0.04
0.04
0.20
0.02
FeO1
19.03
20.43
22.06
14.05
12.09
MnO
0.47
0.42
0.47
0.35
0.16
MgO
5.48
8.47
11.00
17.44
4.09
CaO
13.42
8.89
4.96
3.84
21.40
Na2O
0.10
0.07
0.04
0.02
0.09
SiO
0.79
0.74
0.37
0.92
55.19
54.25
1.27
1.49
0.63
1.63
8.95
13.62
6.34
5.34
15.80
0.04
0.04
0.10
0.18
0.02
5.15
4.14
7.50
3.78
2.78
0.04
0.03
0.07
0.05
0.02
9.15
6.61
10.95
15.51
6.33
15.76
10.78
17.39
15.88
12.85
5.05
8.20
3.91
3.43
6.84
0.02
0.02
0.00
0.00
0.02
0.05
0.00
0.05
0.00
0.05
Tota 100.1 99.96 100.59 l 7 Calculation on 6 Oxygen
100.0 0
100.57
TiO
Total
99.64
0.11 99.25
Calculation on 12 Oxygen
0.09
SC R
1
Mn O Mg O CaO Na2 O K2O P2O
NU
MA
0.00
Al2 O3 Cr2 O3 FeO
0.12
2.43
99.82
D
0.11
99.97
99.90
2.989
2.998
3.003
Si
1.928
1.960
1.929
1.975
1.903
TE
P 2O 5
LUV13 4/10
52.78
2
K2O
OLK1 514
55.47
2
53.32
LUV18 4/10
T
UV58 /10
Clinopyroxene UV66 UV58 2/11 /10
IP
Garnet UV66 2/11
5
3.026
2.991
Ti
0.068
0.045
0.043
0.020
0.052
Ti
0.066
0.034
0.041
0.017
0.043
Al
1.858
1.907
1.889
1.922
1.921
Al
0.382
0.567
0.273
0.225
0.653
Cr
0.004
0.002
0.003
0.011
0.001
Cr
0.001
0.001
0.003
0.005
0.000
Fe2+
1.155
1.266
1.336
0.807
0.742
Fe2+
0.107
0.082
0.126
0.073
0.082
3+
0.049
0.040
0.103
0.040
0.000
Fe
3+
CE P
Si
0.070
0.045
0.066
0.046
0.025
Fe
Mn
0.031
0.027
0.030
0.022
0.010
Mn
0.001
0.001
0.002
0.002
0.001
Mg
0.629
0.969
1.246
1.888
0.462
Mg
0.493
0.348
0.596
0.827
0.331
Ca
1.107
0.731
0.404
0.299
1.741
Ca
0.610
0.408
0.681
0.609
0.483
Na
0.015
0.011
0.006
0.003
0.014
Na
0.354
0.561
0.277
0.238
0.465
K
0.001
0.001
0.000
0.000
0.001
P
0.007
0.007
0.006
0.000
0.007
0.000
0.003
0.000
0.003
Total
7.971
8.003
8.016
8.016
7.979
P 0.003 Tota 3.995 l End-members CaE s 7 CaT s 8
4.003
4.034
4.011
3.963
3
4
1
8
4
8
3
11
19
48
10
17
42
6
4
11
4
0
48
33
55
56
27
5
4
8
17
7
AC
1135
66
K
End-members Schorlomit e-Al Morimotoi te
1 2
2
1
NaTi grt Morimotoi te-Mg
1
1
Sps
1
1
1
1
Prp
20
32
41
63
2
1
Jd
1
Aeg Di+ Hd En+ Fs
15
ACCEPTED MANUSCRIPT
41
42
44
26
26
Grs
31
20
7
6
55
1
3
2
1 0.063
1 0.054
1 0.030
XcatMj
4 0.144
2 0.081
SC R
1136
AC
CE P
TE
D
MA
NU
1137
4
IP
Adr Other
7
T
Alm
NaT i cpx
67
4
2
5
ACCEPTED MANUSCRIPT
1138
Highlights
1139
Apatite and quartz/coesite exsolutions were found in garnet and clinopyroxene hosts
1141
Eclogite and grospydite rocks were derived from depths about 200–260 km
1142
Original rocks were transformed during stepwise decompression and cooling
AC
CE P
TE
D
MA
NU
SC R
IP
T
1140
68