- Email: [email protected]
The chemical composition of some stony meteorites
OeoehImlu
et c2cm!mcwa
ACta.
1956.
Vol.
9. PP. 279
to 289.
PcfeMon plarLtd..London
The chemical compodion of some
stonymeteoritea
H. B. WII~ Universityof Chicngo,Institutefor NucleerStudiee,Chicego (RUM& 20 sepktnber1966) Abhrcf-New em the
evidence ie pramted
for the existence of two main groupo among the chondritse. These Gum (1963). with 28 and 22 per oent total iron, respectively.
H and L groupaof UBFPand
Subdivirionof the H-groupinto nuhgroulm of differentchemicalcompoeition indiecussed.New enalyeea of twenty-onestony mete&tee, includingelevencnrbonsceoua ohondritee,are presented.
As early as 1878 NORDENSKI~~LD had noted great uniformity of chemical composition of a great number of chondrites. This uniformity is especially well illustrated when the composition is expressed on an oxygen-free basis as atomic percentages in the way suggested by WAHL in 1910. In recent years the uniformity has been observed to be even more pronounced than was earlier thought. This is mainly due to better analytical methods, which give more accurate figures for the minor elements. This uniform composition, varying only in the state of oxidation, was regarded as indicating the origin of stony meteorites from different layers of the same planet, and as suggesting a similar model for our own planet. In 1953 UREY and CRAW made a compilation of all available analysis on stony meteorites. They divided them into “superior analyses,” and others which on evidence gathered in recent years must be in error. Ninety-four analyses of chondrites were considered superior. Among those discarded were many old analyses and analyses in which composition differed very much from the average. From consideration of the superior analyses UREY and CRAIO made an interesting observation. The total iron content was found to be grouped around two distinct values, namely 28.68 per cent Fe and 22.33 per cent Fe, and these two groups could not be transferred into each other by means of oxidation or reduction. It seems then more likely that the chondrites have their origin in two planets rather than in one (UREY and CRAIG, op. cit., p. 78). The two groups were named the high (H) and low (L) groups after their high and low iron contents. The way in which UREY and CRAICJ made their choice of analyses has been criticized. To discard analyses, for example, because some components differ strongly from the mean, haa been regarded as inconclusive. However, it must be said that no single analysis was discarded on the basis of its iron content. Common reasons for rejection of analyses were, “No alkalis, Al,O, = 0” (Maziba), “MnO = 5.50, Cr,O, = 1.19” (Limerick), or “No alkalis, all Fe as Fe” (Otomi), etc.
NEW EVIDENCESCONCERNINNO THE H- AND L-~ROTJPS In spite of the above criticism, it is now evident that UREY and CRAI~‘S choice of “superior” analyses is in general correct, although the basis for discarding an analysis is in some cases unsound, and has resulted in rejection of good analyses. 279
H. B. WII~ Table 1. An
Fe
AI&yet CaItmmmma chundh TYP I 1. Tonk
(H) CHBISTIE (caBIs~& Author Author
“3. z*a
4. Nogoye
1914)
l?BIEDEEIM (&&IEDElUM. 1888)
5. Cold Bokkeveld 6. 7. 8. 9.
Ni
Mighei Nawnpali Haripura Boriakino
10. Santa Cnlz 11. bblIT8)’
0.07
0.00 o*Oo
8::
;:g
0.00
0.00”’
040
Wo~~lea and HassIe (WC)=. 1859 end 1860) Author Author Author Author A&IUEEVA (Kvaahe, 1948) Author Author
0.00
Author zutk (Waa~,
15. Felix 16. Mokoie Chondti u& lb-19 per a? me& Fe(H) 17. Haineut 18. of&ley 19. Tromby 20. Aarhua 21. Colleecipoli
24. Indamh”’ 25. Seint-Seuveur ChonaXtea with 7-8 pcz met. Fe(L) 26. Monte dee Fortes 27. Linum 28. Varpaiejlirvi 29. MCKINKSY 30. Mern Aciwt&iU 31. Norton County (Bu)
Author (Wm. 1960 partial)“’ FlR.EB%AN (b&w, 1902) Author Author Author A;goy
bfE
22. Ochanek En&a&e &ondri&d 20-26 p cent me& Fe(H and HH) 23. Hvittia
1950)
1QbW
~OUBITZEN
Author (WA=, Author
19bOb)
Bosae~abr (Bows~aiiar, 1903) Wafirnus (l%sxww 1916) Author RAOULT (Lncmur,
-
0.33
FeS
SiO,
TiO,
16.11”’
22.42
0.09
1.92
0.15
15.07 18.38
22.66 22.71
0.07 0.07
1.65 1.62
0.19 0.23
8-97”’ 8.44
OXMI
o-00
0.00
O-00
8:; o*OO 1.16
8:: 040 0.03
0.00 o*OO
8::
9.04 7.67
0.72 4.02 2.19 4.72
1.43 1.60 1.36
0.09 0.07 0,07
2.69
l*lb”
0.00
164Q lb.16
* MnO r
27.18
-
2.36
28.09
-
1.87
8.16 27.33 10.06 / 27.81 7.67 27.08 14.93 j 26.39 2*79’d’126.73
0.08 0.08 0.09 0.08 0.16
2.29 2.15 E:E 3.11
0.19 0.21 0.17 0.19 0.16
129.36 ~28.69
0.12 0.09
2.19 2.19
0.19 0.21
6.43 5.12 6.49 5.48
33.62 34.82 33.23 33.96
OTS 0.13 0.10
2Y8 2.93 2.91
0.18 0.20 0.20 0.21
0.08
4.76
33.67
3.24
0.68
o-00
0.00
6.74
33.40
0.10
2.61
0.19
1.63 1.88
0.06 0.13
6.16 6.11
36.17 36.66
0.10 0.14
3.09 1.91
0.29 0.32
O-09
6.21 6.64 6.23
37.19 37.49 36.21
0.08 0.16 0.18
3.17 1.46 3.67
0.40 0.34 0.31
6.37
36.81
0.11
4.11
0.26
7.27
41.63
-
1.55
-
1.97
0.13
~2/pceI_(ornlulEites)
13: Warrenton 14. Lance
c
co
ises of stony
18.69 1.61 17.30 18.30
1.93 1.66
L9.14
1.58
i 0.10
!0*04
1.96
! 0.07
o
-
-
I
10.40
1.38
0.06
il 13.30
36.70
!4*13 !5*73
1.83 1.62
0.08 0.12
114.20 114.37
36.26 33.40
0.06 -
1.45 3.29
0.26 0.06
0.88 8.89 7.58
1.18 1.24 1.09
0%
6.14 7.31 6.97
39.77 39.41 39.28
0.06 0.14 0.17
3.30 3.73 4.32
0.32 0.31 0.14
7.81 8.09
0.79 1.09
0.04 -
6.47 6.24
39.77 41.38
0.14 0.17
3.42 1.26
0.31 0.17
0.06
0.61
0.16
1923)
cc1
Author Author Author (WAHL and WIIP, 1960) Author (WIIK, 1950) m
MOURXTZEN
Author
-
0.73 ~
11’Crnran reports9 u rulphidm0.13 per cent. free S 1.44 per ant. and SO, 6.90 per cent. All thin9 Is cilcuhted for the mke of cornp&eon with the other uulyeee-to FeS. M *OR per cept SO, here cslctiated to FeS. 111FBIBDHPY ‘8’ 1.61 peromt?? I + COO. “’ 1.02 per cent S md 2!3-78Fe,O, calculatedby author to Fe8 and Fe0 mpectlvely. I61The nut&al WUIdried at 120°C before umplu weretaken. In the drIesImaterial W&~R found 10.5 per cent water but he did not Indjcate it in the mulysla. beuwe he bellwed the water van of tarnstrial origin. Author hae.replacedIt and reclrlculatedthe m?Jyc.l#to 100~00per cent. 1“ 1.01 per cent NIO wu cstlculstedto NI.
280
The chemicd
caqpoaitimt of mome&my metemikw
Fe0
K,O”’
I
P,O, ( H,O+
H,O-
1Cr,O,
-I
NiO
COO
C
I 9.40
13.71
1.34
3.24
0.36
0.11
11.39 9.45
15.81 16.10
1.22 1.89
0.74 0.75
0.07 0.07
0.28 0.41
20.28
19*05
2.52
0.18
0.15
23.34
20.24
1.55
1.12
Tr.
20.17 IQ.13 xt.76 15.12 24.54
18.73 1946 17989 18*04 19.35
1.56
22.34 21-08
10.74
10.92 ! 0.12
19.89 18.68 10.85
3.43
10.5
0.36 0.33
0.86
2.70
1.23 1.34
3.10 4.83
0.35
2.04
1.62
::: -
t:
21.16 19.77
2.30 1-92
o-12 Qo4
0.32 0.32
9.23 9.98
1.10 2.44
0.39 044
1.64 1.50
008 0.08
2G4 24.80 22.84
23.87 23*57 23.54 23.74
1.99 2.17 2.64 2.20
0.55 0.69 0.58 0*59
017 0.23 0.14 oa
0.35 0.20 0.32 0.34
0.18 0.25 0.10 o*OO 1.40 0.18
0.50 0.58 0.49 0.44
26.22
19.74
5.45
062
0.14
-
0.80
25.43
23.98
2.56
0.51
0.04
0.38
Il.14 10.21
23.30 23.47
1.89 2.41
0.76 0.78
0.15 om
Om 0.30
1.79 1.69 1.18
0.72 1.12 l-31
0.11 0.23 0.24
@31 0.15 -
0.59 0.11 0.07
0.03 0.05 oa6
6.90
23.10
1.59
0.66
0.15
0.23
0.24
0.02
0.34
23.23
0.74
1.26
o-32
-
-
14.98
l&92
0.70
Tr.
@OO
P= 0.08 0.52
oal 0.21
17.48 17.00
0.95 1.12
1.01 0.96
0.11 0.21
0.52 0.17
2.80 1.17 O-09
-
2.23 0.36 2.03
::: 2.01 2.22
23.64 24.03 23.42
2 3
1.30 2.48 2.50 4*00 -
008 O-07
8.26 7.39 5.94
4:3 lOOa 101.02 0.23
1.49 1.53
0.00 0.06
1
1.52
O-42 0.36 O-38 a.45 0.30
8:: 040
0.08
0.30 0.52
-
0.45 0.43 OaO
-
0.62
O;Q
10&l 101.11 99.63
0.36
99.56
0.47
100.62
16
99.99 100.29
:i
-
0.15
-
100.24 99.52 99.38
:8
99.52
22
0.86
98.81
23
0.60
99.77
0.93 1.16
100.33 99.75
G
0.56
040 -
GO0
102-62 100@4
0.46 0.45
-
t3.6.
0.47 0.15
3;s
loo-16 99.19 101.83 99.97 97.22
-
oal
0.52
-
2.54 2.78
sum
94.59
!h.
15.17 12.66 16.41 13.70 8.72 2.96
0.87 0.15
-
1.50
8:; 826 0.23 -
2.07
bfign.
0.69
045 0*05 0.16 0.07 O-20
0.16
a
21
(WJ,
0;s
0.30 cl12 0.28
Ei 0.21
0.02 0.07 0.10
0.36 0.27 o-66
0.75 1.20
0.22 0.18
0.27 0.05
044 0.24
0.14 0.00
0.51 0.14
0.13
O-04
0.02
0.19
0.17 : 0.07 ! OaO
13.21 13.95 12.68
25.38 23-31 23.94
1.81 I *68 1.88
0.71 0.70 0.83
@13
12.82 11.57
23.82 25.83
1.79 2m
WI0
40.72
0.66
-
99.51 99.61
040
471A partlal~analysls of Fell%wu de by the author and pnbltehed by WAHL In 1950. It dIUmla mm detalle from the one now p-t&. Tlrc materl~l wu from a different anra. 181 Ioderch hu formerly been Usted u a cubo~oeo~ chondrlte. Prom the new analy~le It Is evldent that lodarch L aa emrutlte eh-ta clwiy related to ftaint-sauveur. I@*.some of the values for allullea have been detamlacd by Qlroxor EDWAWI and JBARNZ lrnnsol~ ulna the method of EDW~ and UKZY (1156). Tk are the vJua for the foilowtas atones: Oqtuetl, Ivune. Cold Bokkeveld. Yt&ei, tjulpiua. Murray. P&x. Hand Indarvh. the other carbormceom chondrttee arid -6y were made with Ilame photometer by the author. AU other of awe alk&en-and YR Wocrt~~?W+-hwe be811 determhted urlna the J. L. RWmi method. *I*’ Jrn ot lunltlon reducal With H,Q. C. md S. The o~khtboa of Fe. FeO. Nl. u&d CO t&en LDto cooaldentbn. Thb number b m i~ppfoxh~te e3aoaon of the wwmt of wganlc matter. C-MO
pp.)
281
Ii.
B.
Wna-
One example is the analysis of Orgueil by PISAXI. It was discarded because 13.~3 per cent FeS was reported. This very high number for FeS is now shown to be correct, and even somewhat too low (Table 1). It may be worth noting here that high sulphur contents are by no means rare among the carbonaceous chondrit,e group to which Orgueil belongs, as is shown below. The H- and L-groups seem in every case t,o be real and well grounded. In Table I is shown all complete meteorite analyses previously carried out by the author. In Table 2 the results are shown on a water-, sulphur-. and carbon-free basis. In Fig. 1 the iron contents are plotted in essentially the same way as that employed by UREY and CRAIG, except that atomic percentages are used here. while URET and CRAIG plotted their values in weight per cent. One ot,her variation has been introduced. The present data are plotted on a water-, sulphur-. and carbon-free basis. On this basis the carbonaceous ehondrites are directly comparable with the analyses of all the other groups of stones. This would not be so if the volatile constituents were included in the analyses. Only two analyses do not fall into the H- or L-groups, and no single one lies between them, as will be seen from Fig. 1. The two analyses which lie distinctly outside the high or low groups are Norton County and Indarch. Norton County is an achondrite consisting almost entirely of enstatite. The achondrites are extremely variable in chemical composition in accordance with their variation in mineralogical composition. Indarch has more iron than the meteorites of the H-group. It has been listed as a carbonaceous chondrite (MERRILL, 1915), but it is evident from the present analysis that it should be listed among the enstatite chondrites. That Indarch is closely chemically related to the enstatite chondrites was pointed out once formerly (WAI% and WINK, 1951). The analysis of Saint-Sauveur by RAOULT(LACROXX,1923) is analogous. These two enstatite chondrites alone form a group different in chemical composition from the other enstatite ohondrites. They might be termed the HH-group, because of their high iron content-the highest among the stony meteorites. Two D;, nish meteorites analysed by ME MOUR~TZEN have been plotted in Fig, 1. They are included beoause the method of analysis is exactly the same as that employed in the present analysis. The author is grateful to Miss ME MOUR~TZEN for permission to use these results. The advantage of comparing analyses made by the same analyst using the same method is that, if errors of absolute value occur, they probably apply to individual analyses in equal measure and direction. In Fig. 1 are plotted three carbonaceous chondrites not analysed by the author (Tonk, Nogoya, and Boriskino). The carbonaceous chondrltes are of special interest for this interpretation, and for this reason all complete analyses on carbonaceous chondrites were plotted. Some of the analyses carried out by the author have been made for private persons and institutions over a period since 1948. They have been made for purposes other than those of interest in this paper, and have not been selected in any way. Fig. 1 clearly shows that there are two well-defined main groups of stony meteorites which cannot be transferred into each other by changes in the state of oxidation. The 28-58 per cent total iron in the high group, as in UREY and CRAIG. is somewhat too high. 26 per cent is a more correct figure. From Tables 1 and 2 uniformity of chemical composition within these groups can be seen. Small 282
mea.Fe
ch*
21 collalci
is-la
4.07 2.22 4.76 0
26.72 26.97 26.17 24.82
20.62 22.23 21.44 21.79 20.63
24.16 34.04 36.63
6.76 6.8s 7.44 7,711 7.89
19.43 24.78 26.84
14.79 16.12 16.71 17.73 18.62
3.80 4.61 4+4 4.16 3.86
4.48 9.26 9.61
3.79 3.22 3.46 3.84 3.32
3.29 4.18 3.61 4.41
7.10 e-s3 7.87 6.20 12.05 2.16 6+6 6.97
14.20 16.82
14.82 3.21
8 0 8 0
0 0
8
26.68 26.28 26.18 26.76 27.00 2646 26*s6 26.13
26.63 26.32 26.68 26.76 26.03 27.16
Fe in FOB
0.46 14.91
mot.
Fe Ni
T
IO-07 IO.77 9.66 9.89 8.78
0.26 0.00 0.17
8.60 7-74 6.24 6.63 4.46 6.22
la-68 19.76 18.31 !O+vJ i4.96 13-30 IQ-Q6 10-16
Ti
1.10 1.17 1.01 OYO 0.76 0.04 1.01 -
Al
Mn
-
0.16 0.16 0.17 0.16
0.26 0.24 0.11 0.24 0.13
1.64 1.63 GO 1.28 o+s
0.03 3.66 0.12 4.06 0.16 0.12 5:: 0.16 1.36
37.43 33.68 055 32.40 -
27.72 32.48 32.14
K -.._
-.
P
ct -
Sum
1.36 1.37 1.26 1.96 2.28 1.16
0.18 0.23 0.13 0.26 0.28 0.17
0.27 0.17. 0.06 0.06
1.26 1a23 1.47 I! 1.77 1.34 i -94 2.11 1.77
0.22 0.37 o-33 0.30 0.43 0.11
100~00 lQO*OO 100~00 16Oxlo 100~00 1QOxMI
0.23 0.10 0.22 0.21 0.04
0.28 0.20 0.47 0.38 0.10
160*00
loOx)O 1OOM lOO*OO lOO*OO lOO*OO
0.14 0.30 100~00 0.42 0.27 lOO*OO 0.14 0.08 lOO*oo
0;7
oT3 0.24 0.12
lOO@O 1OOXKl ! 160*00 ig 100~00 n
P
f
% B g
% e
s
8
e
8.
0.16 0.43 0.26 0.36 0.27 0.33 0.31 0.39
I? &
100XlO 100*00 loO*OO lOOa 100-00 lOOMI lOQ*OO 160~00
O-32 0.39 0.33 @36 0.43 0.27 o-so 0.33 0.32 0.40
0.16 0.30 0.29 O-26 0.23
0.04 -0.01 -0.06
0.16 0.M) 0.26 0.26 0.21
0.71 2.20 0.37 0.96 1.87 0.14 1.17 1.81 0.26
::; 1.73 1.63 1.14 1.M
2.19 1-2s 2.8i 1.07 2.21 1.07 2.64 0.96
0.40 1.37 ::: D-07 ::: 0.24 0.10 ::: 0.29 0.17 i:E 0.05
I .QS 8.63 0.62 w13 0.13 lOO*OO lOOMI 1.81 1.97 0.12 0.33 2.71 1.95 0.11 0.47 E lCMM0
-
N8
-
61.69 -0.41 -0.21
34.60 32.08 32.M) 32.72 34.80
31.18 24.87 24.66
31.68 31.72 31.82 32.34 31.43 31.11
33.03 33.10 33.18 34.32
0.07 32.78 0.19 32.67 0.19 33.19 0.17 Sl*s6 0.19 31.76 0.14 32.73 0.17 33.69 0.19 33.w
3.32 0.22 0.26 X:: 0.30 1.66 0.26 0.24 0.20 :::
2.42 3.26 3.22 2.84
3.20 3.17 E 290 0.10 2.92 3.16 X:2 4.16 0.12 2.12 o-10 2.26
-
32.77 @14 31.36 0.11 31.86 32.08 8:;
36.28 36.41 36.80 36.67 37.63
L
0.11 3.07 0.17 2.68 0.22 !E 2.66 0.26
L
0.06 33.01 0.07 0.12 .33*17 0.10 0.08 33.61 0.06 33.91 0.14 32.62 0.12 OG 0.08 32.38 0.07
0.03 0.07 0.07 0.06
3140 32.02 t1*8s Ez 32.07 0.08 31.19 0.03 30.36 0.07 31.39 0.08 32.70
0;8
30.44 31.12 30.43
---
Si
r. carbon. and eulDhur-fiw bseie
1.81 0.06 1.79 0.08 1.61 0.12
1.62 1.74 1.49 1.79 144 1a46
1.36 1.46 1.31 1.28
1.89 1.41 1.41 1.47 1.63 1.34 1.41 1.38
::3”:
co
sonwatel
-
IO.67 IS.14 ~0-69 1.44
Fe aa xid. -_.
044 0.16 46.36 -0.04 -0.61 -0.11 0.28 0.00 -0.03 oao w Of the duplicate analysts listed in Tabk 1 only thoee made by the 8uthor am listed here.
Aelbndrirc 31. Norton County (Bu)
28. v 2Q. Me YWimney 30. Hem
ccw
PQ cent
chona* with 7-8 pm md. Fe 26. Monte dm Fortea 27. Linum
24. Indarch”’ 2s. hint fknweur
23. Hvittis
EMhtirscAodkke
22:OCJ
ha
Cold Bokkwrdd”’ Miglmi Nwapli HuipurS Borirtino &nticNs Yumy
17. Hainaut 18. Onkley .I$ p$$v
6. 6. 7. 9. a. 10. 11.
1: Nopya
Type II
2639 27.34 27.41
Fe total
Table 2. Atomic ~ercenta .
H. B. Wnx variations may very well be partly accounted for by errors in sampling and analysis. Imperfect sampling is the cause of many of the unexplained deviations from the mean. It ie clear that an analysis of, for example, a IO-gram fragment of a coarse and often brecciated stone, cannot be representative of the whole, and the rarity of the material frequently makes such analysis necessary. For many meteorites
1INDARCH
’
-
Fig. 1. Ii-on content in stony meteorites. Graphic repreeentation of data in Table 2. The f3gurw a-e etomic percentage43on volstile free b&e.
the sample should be even larger than for analysis of igneous and metamorphic rocks, as the minerals are extremely unevenly distributed. The achondrite, Norton County, is a suitable example. Due to to the generosity of Professor LXNCOLN LAPAZ, one half-kilogram of the stone was made available for chemical analysis. In the course of crushing and grinding the whole sample, only three small rounded 284
fragmenta of metallic nickel-iron were found. The metal amounted to O-73per cent by weight, of the whole. In an analyai~ of a IO-gram sample, thb metallic Fe would very probably never have been detected. Analytical errors, eien in much
leea compliceted siiicete analyaee than thoee of meteoxites, are still surprisingly great, a8 ie ahown by the inveetigation of FAIBBAIM and co-workers (1953). OB mu C!ABB~NA~E~~~ CEOND~UTES, TlmCil -01 SUBDIWSIONS OB TEE “HIQH” GBOUP The fact that the carbonaceous chondritea all belong to the high group is of special interest. They are therefore con&&red at mrne length here. The carbonaceous chondritee have more free carbon and usually more water and sulphur than the ordinary chondritee. The nature and amount of carbon compounds ie of great interet3t. The &ate of oxidation is high. The stones very easily dhdntegrate into a looee powder. This occum BOeasily that it is almost impoeaible to make thin sections for mineralogical investigation. BEBZEIJUS, who made the iirst complete general analof a carbonaceous chondrite in 1834 (Al&, fallen in 1806) thought at fir& that the specimen WBB not meteoritic. The 17 per cent water reported earlier by TEEXAED W(LBdoubted by B~BZELIIJS. However, water in amounts of this magnitude ia not at all unwmal in carbonaceow chondritee. In all reported analyaeq including thoee recently conducted by the author and recorded in this paper, the water in d&tilled out in the presence of an oxidizing agent. The water reported ie therefore the total oxidized hydrogen, involving the water bound aa (OH)- in minerals and the water formed by comb&ion of organic compounds. It is remarkable that hydrated mine&~ occur in the carbonaoeow chondritee. The first hydrated mineral (chlorite) found in a meteorite was in the carbonaceous chondrite Staroje Boriakino (KVASEA, 1948). Knowledge of the chemical and mineralogical compoeition of thisgroup of meteorites is still imperfect. In fact, of the twenty known carbonaceous chondrites, seventeen have been ahemically investigated. Complete analyeee are reported for only six. Theee are Gold Bokkeveld, Felix, Indarch, Nogoya, Staroje Bori&ino, and Tonk. All of these are reproduced along with the present reeults in Table 1. There are in addition incomplete analy~ of the seven stones, Alais, Kaba, Land, Grgueil, Mighei, Mokoia, and Murray. BOATO (1954), in the course of isotopic analysis of carbon and hydrogen in twelve carbonaceous chondritxc, determined total carbon and hydrogen (reference is made to hi8 recult8 below). Among theee &ones were Haripura, Ivun8, Nawapali, and Santa Crux, not previouely subjected to any chemical meaeuremente. The true nature of some of these etonec listed as carbonaceous chondritea is doubtful. Grazac, originally deaaribed as a txdomcmua chondrite by DAUBBE& and ST. MEUNIEB, haa been re-investigated by LACEOIX, who doubte ita meteoritic origin. The meteoritic origin of Simonod is eimilarly doubted. Crasoent haa not been invetrtigated at all, but it ia listed as carbon~ua (PBIOI+-HIY’Saatalogue, 1953). A careful investigation of the organic compounde in Gold Bokkeveld has been published by G. lKum.,~sm (1952). All other d&oumea concerning the organic compounde in carbonaceous chondritea con&t of vague remarks such as: “A 295
H. B.
WIIK
spice-smelling compound was obtained” or “a white sublimate without smell was obtained” or “a grmy substance was left after extraction with ether and tre&ment on steambath.” In fact, the organic compoundsare the lea&-well-knownsubstances in the carbonaceous chondrites. This is partly due to the fact that only very small amounts of these rare materials are obtainable by extra&ion. The author conducted some new analyses of the carbonaceous chondrites. Attention was directed mainly towards the major elements. These new analyses are listed in Tables 1 and 2. The material wm that left over from BOATO’Swork (op. cit.), and the original sources of the meteorites are listed in his publication. It is evident that there are three types of carbonaceous chondrites, and they have been grouped in this way in Table 1. The first type, of which Orgueil, Ivuna, and Tonk are examples, have nearly 20 per cent water (all H as H,O), 22 per cent SiO,, and 15-18 per cent FeS. All S is calculated as FeS, although it is evident that smell amounts of S are bound in organic compounds. In fact, some sulphur occurs as SO,. They have no metallic nickel-iron. It is very probable that Alais also belongs to this sub-group. The results of analysis by THENARDand BERZELIUSare indicative of this, though it is difficult to express theirs in the modern form. It is unfortunate that only a few grams of the first obgerved fall of a carbonaceous chondrite is preserved. Cold Bokkeveld is representative of the second sub-group. The group includes Cold Bokkeveld, Nogoya, Mighei, Nawapali, Haripura, Santa Cruz, Murray, and Boriskino. Sub-group II is characterized by about 13 per cent water, 27.6 per cent SiOe, and 9 per cent FeS. Again there is no metallic nickel-iron. The third group is well represented by Felix. Sub-group III includes Lance and Mokoia. Ornans and Warrenton have the same chemical composition and the same appearance as these three stones of the third group, and all five could be termed Felix-type carbonaceous chondrites, or ornansites. The th$d group have 33-34 per cent SiO,, less than 1 per cent water, and the “normal” amount of FeS in chondrites, namely 6-6 per cent. They have small amounts of metallic nickel-iron. The second group is chemically almost the arithmetic mean between the first and the third, as shown in Table 3. Calculated on a volatile-free basis, all carbonaceous chondrites have practically the same composition, and belong to the H group in their total Fe content. This is clear frqm Table 2. Table 3. Mean values of certain constituents in sub-groups of carbonaceouschondritas Sub-
T
group X0.
I
I
N8IXl08
SiO, i MgO 1
Fe0 1 C
1 HpO / FeS
--
I II
III
I
iI 22.66 ’/ 15.21 Orgueil, Tonk, Ivuna Cold Bokkeveld, Nogoye Mighei, NewaI pali, Haripum, Boriskino, Santa Cruz, Murray Felix, Lax&, Mokoia, Warrenton, Ornans TypeI+TypeIII = 2
_!
286
! 9.77
3.54
20.08 16.52
2.46 0.46
13.36 0.99
8.60 6.05
2.00
10.64
11.28
The chemiad .aompoaition of wme stony meteorite4
BOATO (op. cit.) report8 in many cases less water in the oarbonaceous chondritee than that found in the present investigation. BOATO used 8 combustiondistihetion method. Pennfield tubes were used in the present work with carefully dried PbO, 8s oxidant and trap for the sulphur. The material for analyses w8s the same as ~~OATO’S.The Pennfield method tends to give somewhat low values, and never too high ones, and the reeeon for the disagreement of the results is not olear. The relationship between all the meteorites of the high group seems to be as follows: 2. The carbonaceous 1. The oarbonaceous -Hfl. 8 ti chondrites of the chondrites of the org.m*tta l Cold Bokkeveld type (II) Orgueil type (I) n
--Haa
a.
a.0. l
uldcug.k?&tec
The tXrbOn8WSU8 ohondrites of the Felix type (or the omansites) (III)
4. The chondrites -0 + with 15-19 per cent metallic Fe
6. The enstatite
-0
b
chondrites of the Hvittis type
This is intended only to give a picture of the chemical relations between the subgroups, and not intended to suggest the genesis. There is insufficient evidence at the moment to permit any clear conclusions regarding the genesis of various groups of meteorites. The discontinuity in this series is interesting. The degree of oxidation, the T&le 4. MetAio Fe, weight 1 :aentintheHsndLgroupe+. AU determbtiona with the H & * NH&l emtracth method. Per cent met. Fe
Per oent met. Fe
ThUHpUp
mHgrmcpoorJd.
orguefi_
Hainaut
Imma Cold Bokkeveld Mighei NawIbpli H&ps8nticNz H-Y
MeY
Tromy Anrhus Rioh8rdton Fore& City Colbcipoli ochaMk o-72
oublui Llmo6
1.30 2.19
W8Ur%Ilt.QIl Ouidder WMlOnde F&x
4.02 4.37 4.71 4.72
:
l-heLfv-2, Monte dam Fortes Linum Holbrook Varpeiejlirvi MoKinney Mern
I
287
15*09 l&16 l&S9 17.30 17.41 18.29 16.30 19.14
6~86
6+N 7.05 7.63 7.81 &09
H. 33. WUK
water and aulphnr contenta, form well-defined ateps, and all the other component8 behave tdmilarly. To date, no example of any di%ae traaiti~ne from one subgroup to another have been found. Awxwdingly, the mineralogical composition muat also be of this d&continuous form. The only qnautitative mineralogical factor exsmkd here is the metallic iron-nickel content. !I%ia shows clearly the discontinuity in the degree of oxidation (Table 4). only the metallic Fe is recorded in tb table. The content of nickel ie &no& -n&ant. In Table 4 are to be found some stonee not listed in Tabkm 1 and 2. Only pa&al aua+m were made in these casea. It will be seen tirn the Table that there are disaontinnitiae in the st&ee of oxidation. A snrpriaing ferture is that the valuee seem to form an approximately geometric se&~. The group@ of the results around numbem 2, 4, and lt3 ptw cent may be q&e a&dent& certainly the number of results is ineticient fo merit any far-reaching oo~cluaion. The low group mema to have only on6 oxidation state. The Fe8 cxmteut is al80 very constant, and accxridingly alI the pointa repwaanting this group are gathered in a small area in F&J_ 1. It is surprising that only the high grnp exhibit8 variation in the &ate of oxid&ion, while the low group baa a co&ant oxidation state. l?urther invesfigation may chow greater variation in the low group than ie exhibited by the present ;reeulte. APPBNDEC
T~~~~~~~a~~~~f The composition of stony
SkmyAcfcwika. t3tmse-~m
Table I
meteoriteta. as praaoted in Table 1, abows the cations aa oxides, solphi* etc.’ This system is conventional, and do5 not in all cameagive a true rq53at5tation of 5iMrslogi~l facts. thccompmitio5beoat5athech5Jicaluufiaisdol5notfu5ishtbenan55ry For example, alI 8 is calculated to FcS, in spite of the Cwt that in msmy msteotitea there are emall sm0unt.e of (Ca, IyIn)8 (o1dbamit.o) and F&r@, (B), rml in cer~naceoun of “0rgar.W imlpbur. The amounta of tbae m&m&s would have chcndz+tae, evesIllmnuaznCMnt.0
tabelmowninordertopLaoepropealySsearellasCrand~ ThemimmQkNquantitetive analyiii~ is dii5cultto obtain. 0ldhatnite can be extract& with water. but the operation is ha&y quantitative because of the Mn content. CaO CM be found in &no& all waterertracts from
tiny metwritm, particukuly from the enstatite chontite. The author bebvea themfore that oldhsmite ia a far mom wmmon conutitu0nt in atony meteorites thub wm formerly euppowd. Phaxphorus is another element thst ia eqdy difficult to plaoe. If it ocours mxinly as schroibersite, (Fe, Ni, cO),P, it should be l&cd as P, but if it occurs as lllsnriljtd and/or apatite it should be listed as P,O,. Tha author bolicvcm that achmibemite scaroely ocouni in stony meteoritea There ere two reasons for this. (I} P forms mine5ls with Ca, Al, and Namuch more wily than it dcee with Fe, Ni. and Co, and therefore is exhausted before tbwe is an opportunity for schroibersite to form, Actually, schreihemite has been reported by cbemista dealing with Fe mete&tea; however, in%heae there is, of course, no Al. Ca, or Na. (2) Theauthor’s experience is that the amount of nickel extracted From the sample with F&Cl, * NE,Cl (the metallic Ni) is, within the liits of accuracy, always the snmc as the total Ni obtained fro5 the main analysis. Should schrcibersite occur, the total Ni would have to be greater. NiO can occur only when no ohondrites in which metallic Fe ia prcaent. This happens. for example, in the A there suw no me&&c Fe. Ni. Co tc extract, and accordingly we cannot make any aompariaon bedmen the metallic and the totat nickel. In this caec them is themfare no evidence to show whether schreibemite occurs or not. Anothc.* difhculty with Table 1 is the uncertainty in the oxidixed state of Fe. The amount of Fe0 is oniy a c&uh~ted number obtained by subtraction of the xnctdiic iron and the tmilite iron from the tote1 iron. The Fe8 tends to be, too high. becauwe aU S ~IU calculated to that compound. Acoordingly, the Fe0 tends to be too low. It is almost irnpamible to determine Fe0 288
dire&y. becwee of the pmaeameofnmdilyeohIbk9Nl~~~irm,orgeniccompour&. Whrnmtrgtodirroloetbs~farFeO~~imahrsduoedtoFd).~ thetowlironrrfb~tluntbetrasFeOieo~. (Tbemvll uxunmteofinminekomii ~~~MnddLahrsdin~~~~tbetotrlirondsterminsdtath~nraarrir aommhattoolor. Tbeoomott4~talimmirobtaimdfmmthe~ad*) Fe,Oo,&ouklbe ob~by~oTFd).Fe~rpdFeinFe8fnnnfhb~Mp.~~the lnfimhmetu0ht4mam~~lliC Fe0 L not known, the Fe,O, omn&bedetammdeifhsr. iron,f~~~guppacdmtfooomr. ~hkispdmblytm~~ ItiedSculttound~tJu ironebouldbefclrmdint&eediikentoxidstim8t&8inthermsstone. Wbenmeulkirar AotosUythaemeeam docmnot oeour. however, if~verypomibletbftberekeomeFe,O, fo~~~iptbb~oh~uindiarbdbytbsX-~yporder Tbeehwtalwpowdin~obopdrita petteun (Ih. uuy. privrb eommtim). (Kv~qp.cil.)aab,udlybewithoutfenictol,eitk. Itismastunf~tetb8tfsrrie ironeumotbedebrmmsd. rukefae&ul&iqtheminemlegkmleompo8itkmaf TlKrebDvebam8twnpt8to~ #tqT~&antbeobemimlM&we!& TklebwenotlmeQintendedtoqxaenttbe wimlmiaamt~ibmpaifiaa,butrkindof‘horm”for~ymsbori~ 8unhanoRphi~y
taomi&diugtQbeumdi&brlmumoftbs~inthspasntUiondthe~d
theeaenplio&edminen@yofmeteoritM. ItLinqNNiQJAeCommker ~ttbetnnemodewitboatknowingtheFe/Mgmtiofntbe~pymxsnaurd oliviass(tbsrJioiwttbb~ipbotb~~uruf~rappasd),~rithrd kIlowiqgtheloestionoftbef.kuld~wbinllwlwtfoundexobmk@iufek@=R must&awfombeevenlm?emi&ediq~~abpldedfmmigmoaBead~ mek~ by the C.I.P.W. w.
*-
abnlukmto
tiwrrm
A-1 winh to extend my gratitude to Dr. HAEOLD C. UEEY, rho wgge&ed a ulosar inva&igstion ofthe uarbonaoeoui~ahcmdritm. I am ales indebted to mrrny inutitutio~ and private pssnans for analytiaal mat&al, and for permkkm to um M yet unpublished ‘data. With Dr. GBO~~BEDWABDB and Mr. 0. Jomww of the Univemity of Chiaago, I had &uitfid dkwmions. I am indebted to Mr. E. P. HRTD~XSORfrom United Statea National Maream, and to Dr. C. R. NUSRB from U.S. Geologioal Swey, for aritiaally reading the nubnusuript. This rawan4k was supported by the Natiod 8cienoe Foundation.
Rarrrraare B-9 Boom Bo~x,
J. J. (1634) Ann. PM. ud Ckamie,a 113 G. (1964) &o&k. & Ce. Ada, 6.3OQ L. H., (1903) Butl. Corn. &ok de Fidamio No. 21 CHJusm, W. A. K. (1914) Beco& of the GeologioJ Survey of Jndk, 44.41 EDWABD~, G.. md UBBY, H. C. (1966) &mSes. slC_. A&z, 7, 164 Fs. H. W.. d oo.workem (lQ61) U.S. GeokgM Survey Bulletin No. QMJ tixsxrx, C. (1666) &-Z&r Akiui. IVia. Berlk, l, 346 KVABEA. L. 0. (lQ46) iUwok&xa, Aad. sd. fJ&!?R,4.63 LACEOIX.A. (1033) 0ompt. Rend, 1,661 Yhknxu~~,G. P. (1603) pmt. UB. Not. Afw. Wooh+tos, w 193 Ye9 G. P. (lSl6) #%oc. U76. Nat. Mw. Woakgkm. u, 109 Muxus~, G. (lQ63) QootSm. & Cm. Ado. 4,l NoED~~~~LD. A. E. (1676) Qod. F6rus. i &o&uk Fti.. 4,46 Pwor, C. T, end Eirr MAX H. (1963) CItrlogrre of Msteoritea Britii Mpmna UBXT, H. C.. cad CRUX. H. (lQ63) Qao&im. d Cwmochim. Ada. 4.36 WAEL, W. A. (1910) Z. amap. Ckm.. a 63 wAx& w. A. (lQ6oD) iuilb. iwag, se, 419 W~~~,W.A.(lQ6Ob)&mh+.~Comrodin.Ado,l,3O WAHL, W. A., end Wur. H. B. (lQ60) BuR. Carr. aed. de Pkkwwie. lao. 6 WAEL, W. A., uxi Wm. H. B. (lQ61) G%nnSm.d Ce. AC& t 134 Wm. H. B. (lQ4Q)Sec.Sci. Fems. Pm. Mdk.. 14.14 W~~HLI~ F..-urd HARRIS, E. P. (1660 UMI 1860)Sitt-Ber. AM. Wk. Wk. 86.6; II.666
et c2cm!mcwa
ACta.
1956.
Vol.
9. PP. 279
to 289.
PcfeMon plarLtd..London
The chemical compodion of some
stonymeteoritea
H. B. WII~ Universityof Chicngo,Institutefor NucleerStudiee,Chicego (RUM& 20 sepktnber1966) Abhrcf-New em the
evidence ie pramted
for the existence of two main groupo among the chondritse. These Gum (1963). with 28 and 22 per oent total iron, respectively.
H and L groupaof UBFPand
Subdivirionof the H-groupinto nuhgroulm of differentchemicalcompoeition indiecussed.New enalyeea of twenty-onestony mete&tee, includingelevencnrbonsceoua ohondritee,are presented.
As early as 1878 NORDENSKI~~LD had noted great uniformity of chemical composition of a great number of chondrites. This uniformity is especially well illustrated when the composition is expressed on an oxygen-free basis as atomic percentages in the way suggested by WAHL in 1910. In recent years the uniformity has been observed to be even more pronounced than was earlier thought. This is mainly due to better analytical methods, which give more accurate figures for the minor elements. This uniform composition, varying only in the state of oxidation, was regarded as indicating the origin of stony meteorites from different layers of the same planet, and as suggesting a similar model for our own planet. In 1953 UREY and CRAW made a compilation of all available analysis on stony meteorites. They divided them into “superior analyses,” and others which on evidence gathered in recent years must be in error. Ninety-four analyses of chondrites were considered superior. Among those discarded were many old analyses and analyses in which composition differed very much from the average. From consideration of the superior analyses UREY and CRAIO made an interesting observation. The total iron content was found to be grouped around two distinct values, namely 28.68 per cent Fe and 22.33 per cent Fe, and these two groups could not be transferred into each other by means of oxidation or reduction. It seems then more likely that the chondrites have their origin in two planets rather than in one (UREY and CRAIG, op. cit., p. 78). The two groups were named the high (H) and low (L) groups after their high and low iron contents. The way in which UREY and CRAICJ made their choice of analyses has been criticized. To discard analyses, for example, because some components differ strongly from the mean, haa been regarded as inconclusive. However, it must be said that no single analysis was discarded on the basis of its iron content. Common reasons for rejection of analyses were, “No alkalis, Al,O, = 0” (Maziba), “MnO = 5.50, Cr,O, = 1.19” (Limerick), or “No alkalis, all Fe as Fe” (Otomi), etc.
NEW EVIDENCESCONCERNINNO THE H- AND L-~ROTJPS In spite of the above criticism, it is now evident that UREY and CRAI~‘S choice of “superior” analyses is in general correct, although the basis for discarding an analysis is in some cases unsound, and has resulted in rejection of good analyses. 279
H. B. WII~ Table 1. An
Fe
AI&yet CaItmmmma chundh TYP I 1. Tonk
(H) CHBISTIE (caBIs~& Author Author
“3. z*a
4. Nogoye
1914)
l?BIEDEEIM (&&IEDElUM. 1888)
5. Cold Bokkeveld 6. 7. 8. 9.
Ni
Mighei Nawnpali Haripura Boriakino
10. Santa Cnlz 11. bblIT8)’
0.07
0.00 o*Oo
8::
;:g
0.00
0.00”’
040
Wo~~lea and HassIe (WC)=. 1859 end 1860) Author Author Author Author A&IUEEVA (Kvaahe, 1948) Author Author
0.00
Author zutk (Waa~,
15. Felix 16. Mokoie Chondti u& lb-19 per a? me& Fe(H) 17. Haineut 18. of&ley 19. Tromby 20. Aarhua 21. Colleecipoli
24. Indamh”’ 25. Seint-Seuveur ChonaXtea with 7-8 pcz met. Fe(L) 26. Monte dee Fortes 27. Linum 28. Varpaiejlirvi 29. MCKINKSY 30. Mern Aciwt&iU 31. Norton County (Bu)
Author (Wm. 1960 partial)“’ FlR.EB%AN (b&w, 1902) Author Author Author A;goy
bfE
22. Ochanek En&a&e &ondri&d 20-26 p cent me& Fe(H and HH) 23. Hvittia
1950)
1QbW
~OUBITZEN
Author (WA=, Author
19bOb)
Bosae~abr (Bows~aiiar, 1903) Wafirnus (l%sxww 1916) Author RAOULT (Lncmur,
-
0.33
FeS
SiO,
TiO,
16.11”’
22.42
0.09
1.92
0.15
15.07 18.38
22.66 22.71
0.07 0.07
1.65 1.62
0.19 0.23
8-97”’ 8.44
OXMI
o-00
0.00
O-00
8:; o*OO 1.16
8:: 040 0.03
0.00 o*OO
8::
9.04 7.67
0.72 4.02 2.19 4.72
1.43 1.60 1.36
0.09 0.07 0,07
2.69
l*lb”
0.00
164Q lb.16
* MnO r
27.18
-
2.36
28.09
-
1.87
8.16 27.33 10.06 / 27.81 7.67 27.08 14.93 j 26.39 2*79’d’126.73
0.08 0.08 0.09 0.08 0.16
2.29 2.15 E:E 3.11
0.19 0.21 0.17 0.19 0.16
129.36 ~28.69
0.12 0.09
2.19 2.19
0.19 0.21
6.43 5.12 6.49 5.48
33.62 34.82 33.23 33.96
OTS 0.13 0.10
2Y8 2.93 2.91
0.18 0.20 0.20 0.21
0.08
4.76
33.67
3.24
0.68
o-00
0.00
6.74
33.40
0.10
2.61
0.19
1.63 1.88
0.06 0.13
6.16 6.11
36.17 36.66
0.10 0.14
3.09 1.91
0.29 0.32
O-09
6.21 6.64 6.23
37.19 37.49 36.21
0.08 0.16 0.18
3.17 1.46 3.67
0.40 0.34 0.31
6.37
36.81
0.11
4.11
0.26
7.27
41.63
-
1.55
-
1.97
0.13
~2/pceI_(ornlulEites)
13: Warrenton 14. Lance
c
co
ises of stony
18.69 1.61 17.30 18.30
1.93 1.66
L9.14
1.58
i 0.10
!0*04
1.96
! 0.07
o
-
-
I
10.40
1.38
0.06
il 13.30
36.70
!4*13 !5*73
1.83 1.62
0.08 0.12
114.20 114.37
36.26 33.40
0.06 -
1.45 3.29
0.26 0.06
0.88 8.89 7.58
1.18 1.24 1.09
0%
6.14 7.31 6.97
39.77 39.41 39.28
0.06 0.14 0.17
3.30 3.73 4.32
0.32 0.31 0.14
7.81 8.09
0.79 1.09
0.04 -
6.47 6.24
39.77 41.38
0.14 0.17
3.42 1.26
0.31 0.17
0.06
0.61
0.16
1923)
cc1
Author Author Author (WAHL and WIIP, 1960) Author (WIIK, 1950) m
MOURXTZEN
Author
-
0.73 ~
11’Crnran reports9 u rulphidm0.13 per cent. free S 1.44 per ant. and SO, 6.90 per cent. All thin9 Is cilcuhted for the mke of cornp&eon with the other uulyeee-to FeS. M *OR per cept SO, here cslctiated to FeS. 111FBIBDHPY ‘8’ 1.61 peromt?? I + COO. “’ 1.02 per cent S md 2!3-78Fe,O, calculatedby author to Fe8 and Fe0 mpectlvely. I61The nut&al WUIdried at 120°C before umplu weretaken. In the drIesImaterial W&~R found 10.5 per cent water but he did not Indjcate it in the mulysla. beuwe he bellwed the water van of tarnstrial origin. Author hae.replacedIt and reclrlculatedthe m?Jyc.l#to 100~00per cent. 1“ 1.01 per cent NIO wu cstlculstedto NI.
280
The chemicd
caqpoaitimt of mome&my metemikw
Fe0
K,O”’
I
P,O, ( H,O+
H,O-
1Cr,O,
-I
NiO
COO
C
I 9.40
13.71
1.34
3.24
0.36
0.11
11.39 9.45
15.81 16.10
1.22 1.89
0.74 0.75
0.07 0.07
0.28 0.41
20.28
19*05
2.52
0.18
0.15
23.34
20.24
1.55
1.12
Tr.
20.17 IQ.13 xt.76 15.12 24.54
18.73 1946 17989 18*04 19.35
1.56
22.34 21-08
10.74
10.92 ! 0.12
19.89 18.68 10.85
3.43
10.5
0.36 0.33
0.86
2.70
1.23 1.34
3.10 4.83
0.35
2.04
1.62
::: -
t:
21.16 19.77
2.30 1-92
o-12 Qo4
0.32 0.32
9.23 9.98
1.10 2.44
0.39 044
1.64 1.50
008 0.08
2G4 24.80 22.84
23.87 23*57 23.54 23.74
1.99 2.17 2.64 2.20
0.55 0.69 0.58 0*59
017 0.23 0.14 oa
0.35 0.20 0.32 0.34
0.18 0.25 0.10 o*OO 1.40 0.18
0.50 0.58 0.49 0.44
26.22
19.74
5.45
062
0.14
-
0.80
25.43
23.98
2.56
0.51
0.04
0.38
Il.14 10.21
23.30 23.47
1.89 2.41
0.76 0.78
0.15 om
Om 0.30
1.79 1.69 1.18
0.72 1.12 l-31
0.11 0.23 0.24
@31 0.15 -
0.59 0.11 0.07
0.03 0.05 oa6
6.90
23.10
1.59
0.66
0.15
0.23
0.24
0.02
0.34
23.23
0.74
1.26
o-32
-
-
14.98
l&92
0.70
Tr.
@OO
P= 0.08 0.52
oal 0.21
17.48 17.00
0.95 1.12
1.01 0.96
0.11 0.21
0.52 0.17
2.80 1.17 O-09
-
2.23 0.36 2.03
::: 2.01 2.22
23.64 24.03 23.42
2 3
1.30 2.48 2.50 4*00 -
008 O-07
8.26 7.39 5.94
4:3 lOOa 101.02 0.23
1.49 1.53
0.00 0.06
1
1.52
O-42 0.36 O-38 a.45 0.30
8:: 040
0.08
0.30 0.52
-
0.45 0.43 OaO
-
0.62
O;Q
10&l 101.11 99.63
0.36
99.56
0.47
100.62
16
99.99 100.29
:i
-
0.15
-
100.24 99.52 99.38
:8
99.52
22
0.86
98.81
23
0.60
99.77
0.93 1.16
100.33 99.75
G
0.56
040 -
GO0
102-62 100@4
0.46 0.45
-
t3.6.
0.47 0.15
3;s
loo-16 99.19 101.83 99.97 97.22
-
oal
0.52
-
2.54 2.78
sum
94.59
!h.
15.17 12.66 16.41 13.70 8.72 2.96
0.87 0.15
-
1.50
8:; 826 0.23 -
2.07
bfign.
0.69
045 0*05 0.16 0.07 O-20
0.16
a
21
(WJ,
0;s
0.30 cl12 0.28
Ei 0.21
0.02 0.07 0.10
0.36 0.27 o-66
0.75 1.20
0.22 0.18
0.27 0.05
044 0.24
0.14 0.00
0.51 0.14
0.13
O-04
0.02
0.19
0.17 : 0.07 ! OaO
13.21 13.95 12.68
25.38 23-31 23.94
1.81 I *68 1.88
0.71 0.70 0.83
@13
12.82 11.57
23.82 25.83
1.79 2m
WI0
40.72
0.66
-
99.51 99.61
040
471A partlal~analysls of Fell%wu de by the author and pnbltehed by WAHL In 1950. It dIUmla mm detalle from the one now p-t&. Tlrc materl~l wu from a different anra. 181 Ioderch hu formerly been Usted u a cubo~oeo~ chondrlte. Prom the new analy~le It Is evldent that lodarch L aa emrutlte eh-ta clwiy related to ftaint-sauveur. I@*.some of the values for allullea have been detamlacd by Qlroxor EDWAWI and JBARNZ lrnnsol~ ulna the method of EDW~ and UKZY (1156). Tk are the vJua for the foilowtas atones: Oqtuetl, Ivune. Cold Bokkeveld. Yt&ei, tjulpiua. Murray. P&x. Hand Indarvh. the other carbormceom chondrttee arid -6y were made with Ilame photometer by the author. AU other of awe alk&en-and YR Wocrt~~?W+-hwe be811 determhted urlna the J. L. RWmi method. *I*’ Jrn ot lunltlon reducal With H,Q. C. md S. The o~khtboa of Fe. FeO. Nl. u&d CO t&en LDto cooaldentbn. Thb number b m i~ppfoxh~te e3aoaon of the wwmt of wganlc matter. C-MO
pp.)
281
Ii.
B.
Wna-
One example is the analysis of Orgueil by PISAXI. It was discarded because 13.~3 per cent FeS was reported. This very high number for FeS is now shown to be correct, and even somewhat too low (Table 1). It may be worth noting here that high sulphur contents are by no means rare among the carbonaceous chondrit,e group to which Orgueil belongs, as is shown below. The H- and L-groups seem in every case t,o be real and well grounded. In Table I is shown all complete meteorite analyses previously carried out by the author. In Table 2 the results are shown on a water-, sulphur-. and carbon-free basis. In Fig. 1 the iron contents are plotted in essentially the same way as that employed by UREY and CRAIG, except that atomic percentages are used here. while URET and CRAIG plotted their values in weight per cent. One ot,her variation has been introduced. The present data are plotted on a water-, sulphur-. and carbon-free basis. On this basis the carbonaceous ehondrites are directly comparable with the analyses of all the other groups of stones. This would not be so if the volatile constituents were included in the analyses. Only two analyses do not fall into the H- or L-groups, and no single one lies between them, as will be seen from Fig. 1. The two analyses which lie distinctly outside the high or low groups are Norton County and Indarch. Norton County is an achondrite consisting almost entirely of enstatite. The achondrites are extremely variable in chemical composition in accordance with their variation in mineralogical composition. Indarch has more iron than the meteorites of the H-group. It has been listed as a carbonaceous chondrite (MERRILL, 1915), but it is evident from the present analysis that it should be listed among the enstatite chondrites. That Indarch is closely chemically related to the enstatite chondrites was pointed out once formerly (WAI% and WINK, 1951). The analysis of Saint-Sauveur by RAOULT(LACROXX,1923) is analogous. These two enstatite chondrites alone form a group different in chemical composition from the other enstatite ohondrites. They might be termed the HH-group, because of their high iron content-the highest among the stony meteorites. Two D;, nish meteorites analysed by ME MOUR~TZEN have been plotted in Fig, 1. They are included beoause the method of analysis is exactly the same as that employed in the present analysis. The author is grateful to Miss ME MOUR~TZEN for permission to use these results. The advantage of comparing analyses made by the same analyst using the same method is that, if errors of absolute value occur, they probably apply to individual analyses in equal measure and direction. In Fig. 1 are plotted three carbonaceous chondrites not analysed by the author (Tonk, Nogoya, and Boriskino). The carbonaceous chondrltes are of special interest for this interpretation, and for this reason all complete analyses on carbonaceous chondrites were plotted. Some of the analyses carried out by the author have been made for private persons and institutions over a period since 1948. They have been made for purposes other than those of interest in this paper, and have not been selected in any way. Fig. 1 clearly shows that there are two well-defined main groups of stony meteorites which cannot be transferred into each other by changes in the state of oxidation. The 28-58 per cent total iron in the high group, as in UREY and CRAIG. is somewhat too high. 26 per cent is a more correct figure. From Tables 1 and 2 uniformity of chemical composition within these groups can be seen. Small 282
mea.Fe
ch*
21 collalci
is-la
4.07 2.22 4.76 0
26.72 26.97 26.17 24.82
20.62 22.23 21.44 21.79 20.63
24.16 34.04 36.63
6.76 6.8s 7.44 7,711 7.89
19.43 24.78 26.84
14.79 16.12 16.71 17.73 18.62
3.80 4.61 4+4 4.16 3.86
4.48 9.26 9.61
3.79 3.22 3.46 3.84 3.32
3.29 4.18 3.61 4.41
7.10 e-s3 7.87 6.20 12.05 2.16 6+6 6.97
14.20 16.82
14.82 3.21
8 0 8 0
0 0
8
26.68 26.28 26.18 26.76 27.00 2646 26*s6 26.13
26.63 26.32 26.68 26.76 26.03 27.16
Fe in FOB
0.46 14.91
mot.
Fe Ni
T
IO-07 IO.77 9.66 9.89 8.78
0.26 0.00 0.17
8.60 7-74 6.24 6.63 4.46 6.22
la-68 19.76 18.31 !O+vJ i4.96 13-30 IQ-Q6 10-16
Ti
1.10 1.17 1.01 OYO 0.76 0.04 1.01 -
Al
Mn
-
0.16 0.16 0.17 0.16
0.26 0.24 0.11 0.24 0.13
1.64 1.63 GO 1.28 o+s
0.03 3.66 0.12 4.06 0.16 0.12 5:: 0.16 1.36
37.43 33.68 055 32.40 -
27.72 32.48 32.14
K -.._
-.
P
ct -
Sum
1.36 1.37 1.26 1.96 2.28 1.16
0.18 0.23 0.13 0.26 0.28 0.17
0.27 0.17. 0.06 0.06
1.26 1a23 1.47 I! 1.77 1.34 i -94 2.11 1.77
0.22 0.37 o-33 0.30 0.43 0.11
100~00 lQO*OO 100~00 16Oxlo 100~00 1QOxMI
0.23 0.10 0.22 0.21 0.04
0.28 0.20 0.47 0.38 0.10
160*00
loOx)O 1OOM lOO*OO lOO*OO lOO*OO
0.14 0.30 100~00 0.42 0.27 lOO*OO 0.14 0.08 lOO*oo
0;7
oT3 0.24 0.12
lOO@O 1OOXKl ! 160*00 ig 100~00 n
P
f
% B g
% e
s
8
e
8.
0.16 0.43 0.26 0.36 0.27 0.33 0.31 0.39
I? &
100XlO 100*00 loO*OO lOOa 100-00 lOOMI lOQ*OO 160~00
O-32 0.39 0.33 @36 0.43 0.27 o-so 0.33 0.32 0.40
0.16 0.30 0.29 O-26 0.23
0.04 -0.01 -0.06
0.16 0.M) 0.26 0.26 0.21
0.71 2.20 0.37 0.96 1.87 0.14 1.17 1.81 0.26
::; 1.73 1.63 1.14 1.M
2.19 1-2s 2.8i 1.07 2.21 1.07 2.64 0.96
0.40 1.37 ::: D-07 ::: 0.24 0.10 ::: 0.29 0.17 i:E 0.05
I .QS 8.63 0.62 w13 0.13 lOO*OO lOOMI 1.81 1.97 0.12 0.33 2.71 1.95 0.11 0.47 E lCMM0
-
N8
-
61.69 -0.41 -0.21
34.60 32.08 32.M) 32.72 34.80
31.18 24.87 24.66
31.68 31.72 31.82 32.34 31.43 31.11
33.03 33.10 33.18 34.32
0.07 32.78 0.19 32.67 0.19 33.19 0.17 Sl*s6 0.19 31.76 0.14 32.73 0.17 33.69 0.19 33.w
3.32 0.22 0.26 X:: 0.30 1.66 0.26 0.24 0.20 :::
2.42 3.26 3.22 2.84
3.20 3.17 E 290 0.10 2.92 3.16 X:2 4.16 0.12 2.12 o-10 2.26
-
32.77 @14 31.36 0.11 31.86 32.08 8:;
36.28 36.41 36.80 36.67 37.63
L
0.11 3.07 0.17 2.68 0.22 !E 2.66 0.26
L
0.06 33.01 0.07 0.12 .33*17 0.10 0.08 33.61 0.06 33.91 0.14 32.62 0.12 OG 0.08 32.38 0.07
0.03 0.07 0.07 0.06
3140 32.02 t1*8s Ez 32.07 0.08 31.19 0.03 30.36 0.07 31.39 0.08 32.70
0;8
30.44 31.12 30.43
---
Si
r. carbon. and eulDhur-fiw bseie
1.81 0.06 1.79 0.08 1.61 0.12
1.62 1.74 1.49 1.79 144 1a46
1.36 1.46 1.31 1.28
1.89 1.41 1.41 1.47 1.63 1.34 1.41 1.38
::3”:
co
sonwatel
-
IO.67 IS.14 ~0-69 1.44
Fe aa xid. -_.
044 0.16 46.36 -0.04 -0.61 -0.11 0.28 0.00 -0.03 oao w Of the duplicate analysts listed in Tabk 1 only thoee made by the 8uthor am listed here.
Aelbndrirc 31. Norton County (Bu)
28. v 2Q. Me YWimney 30. Hem
ccw
PQ cent
chona* with 7-8 pm md. Fe 26. Monte dm Fortea 27. Linum
24. Indarch”’ 2s. hint fknweur
23. Hvittis
EMhtirscAodkke
22:OCJ
ha
Cold Bokkwrdd”’ Miglmi Nwapli HuipurS Borirtino &nticNs Yumy
17. Hainaut 18. Onkley .I$ p$$v
6. 6. 7. 9. a. 10. 11.
1: Nopya
Type II
2639 27.34 27.41
Fe total
Table 2. Atomic ~ercenta .
H. B. Wnx variations may very well be partly accounted for by errors in sampling and analysis. Imperfect sampling is the cause of many of the unexplained deviations from the mean. It ie clear that an analysis of, for example, a IO-gram fragment of a coarse and often brecciated stone, cannot be representative of the whole, and the rarity of the material frequently makes such analysis necessary. For many meteorites
1INDARCH
’
-
Fig. 1. Ii-on content in stony meteorites. Graphic repreeentation of data in Table 2. The f3gurw a-e etomic percentage43on volstile free b&e.
the sample should be even larger than for analysis of igneous and metamorphic rocks, as the minerals are extremely unevenly distributed. The achondrite, Norton County, is a suitable example. Due to to the generosity of Professor LXNCOLN LAPAZ, one half-kilogram of the stone was made available for chemical analysis. In the course of crushing and grinding the whole sample, only three small rounded 284
fragmenta of metallic nickel-iron were found. The metal amounted to O-73per cent by weight, of the whole. In an analyai~ of a IO-gram sample, thb metallic Fe would very probably never have been detected. Analytical errors, eien in much
leea compliceted siiicete analyaee than thoee of meteoxites, are still surprisingly great, a8 ie ahown by the inveetigation of FAIBBAIM and co-workers (1953). OB mu C!ABB~NA~E~~~ CEOND~UTES, TlmCil -01 SUBDIWSIONS OB TEE “HIQH” GBOUP The fact that the carbonaceous chondritea all belong to the high group is of special interest. They are therefore con&&red at mrne length here. The carbonaceous chondritee have more free carbon and usually more water and sulphur than the ordinary chondritee. The nature and amount of carbon compounds ie of great interet3t. The &ate of oxidation is high. The stones very easily dhdntegrate into a looee powder. This occum BOeasily that it is almost impoeaible to make thin sections for mineralogical investigation. BEBZEIJUS, who made the iirst complete general analof a carbonaceous chondrite in 1834 (Al&, fallen in 1806) thought at fir& that the specimen WBB not meteoritic. The 17 per cent water reported earlier by TEEXAED W(LBdoubted by B~BZELIIJS. However, water in amounts of this magnitude ia not at all unwmal in carbonaceow chondritee. In all reported analyaeq including thoee recently conducted by the author and recorded in this paper, the water in d&tilled out in the presence of an oxidizing agent. The water reported ie therefore the total oxidized hydrogen, involving the water bound aa (OH)- in minerals and the water formed by comb&ion of organic compounds. It is remarkable that hydrated mine&~ occur in the carbonaoeow chondritee. The first hydrated mineral (chlorite) found in a meteorite was in the carbonaceous chondrite Staroje Boriakino (KVASEA, 1948). Knowledge of the chemical and mineralogical compoeition of thisgroup of meteorites is still imperfect. In fact, of the twenty known carbonaceous chondrites, seventeen have been ahemically investigated. Complete analyeee are reported for only six. Theee are Gold Bokkeveld, Felix, Indarch, Nogoya, Staroje Bori&ino, and Tonk. All of these are reproduced along with the present reeults in Table 1. There are in addition incomplete analy~ of the seven stones, Alais, Kaba, Land, Grgueil, Mighei, Mokoia, and Murray. BOATO (1954), in the course of isotopic analysis of carbon and hydrogen in twelve carbonaceous chondritxc, determined total carbon and hydrogen (reference is made to hi8 recult8 below). Among theee &ones were Haripura, Ivun8, Nawapali, and Santa Crux, not previouely subjected to any chemical meaeuremente. The true nature of some of these etonec listed as carbonaceous chondritea is doubtful. Grazac, originally deaaribed as a txdomcmua chondrite by DAUBBE& and ST. MEUNIEB, haa been re-investigated by LACEOIX, who doubte ita meteoritic origin. The meteoritic origin of Simonod is eimilarly doubted. Crasoent haa not been invetrtigated at all, but it ia listed as carbon~ua (PBIOI+-HIY’Saatalogue, 1953). A careful investigation of the organic compounde in Gold Bokkeveld has been published by G. lKum.,~sm (1952). All other d&oumea concerning the organic compounde in carbonaceous chondritea con&t of vague remarks such as: “A 295
H. B.
WIIK
spice-smelling compound was obtained” or “a white sublimate without smell was obtained” or “a grmy substance was left after extraction with ether and tre&ment on steambath.” In fact, the organic compoundsare the lea&-well-knownsubstances in the carbonaceous chondrites. This is partly due to the fact that only very small amounts of these rare materials are obtainable by extra&ion. The author conducted some new analyses of the carbonaceous chondrites. Attention was directed mainly towards the major elements. These new analyses are listed in Tables 1 and 2. The material wm that left over from BOATO’Swork (op. cit.), and the original sources of the meteorites are listed in his publication. It is evident that there are three types of carbonaceous chondrites, and they have been grouped in this way in Table 1. The first type, of which Orgueil, Ivuna, and Tonk are examples, have nearly 20 per cent water (all H as H,O), 22 per cent SiO,, and 15-18 per cent FeS. All S is calculated as FeS, although it is evident that smell amounts of S are bound in organic compounds. In fact, some sulphur occurs as SO,. They have no metallic nickel-iron. It is very probable that Alais also belongs to this sub-group. The results of analysis by THENARDand BERZELIUSare indicative of this, though it is difficult to express theirs in the modern form. It is unfortunate that only a few grams of the first obgerved fall of a carbonaceous chondrite is preserved. Cold Bokkeveld is representative of the second sub-group. The group includes Cold Bokkeveld, Nogoya, Mighei, Nawapali, Haripura, Santa Cruz, Murray, and Boriskino. Sub-group II is characterized by about 13 per cent water, 27.6 per cent SiOe, and 9 per cent FeS. Again there is no metallic nickel-iron. The third group is well represented by Felix. Sub-group III includes Lance and Mokoia. Ornans and Warrenton have the same chemical composition and the same appearance as these three stones of the third group, and all five could be termed Felix-type carbonaceous chondrites, or ornansites. The th$d group have 33-34 per cent SiO,, less than 1 per cent water, and the “normal” amount of FeS in chondrites, namely 6-6 per cent. They have small amounts of metallic nickel-iron. The second group is chemically almost the arithmetic mean between the first and the third, as shown in Table 3. Calculated on a volatile-free basis, all carbonaceous chondrites have practically the same composition, and belong to the H group in their total Fe content. This is clear frqm Table 2. Table 3. Mean values of certain constituents in sub-groups of carbonaceouschondritas Sub-
T
group X0.
I
I
N8IXl08
SiO, i MgO 1
Fe0 1 C
1 HpO / FeS
--
I II
III
I
iI 22.66 ’/ 15.21 Orgueil, Tonk, Ivuna Cold Bokkeveld, Nogoye Mighei, NewaI pali, Haripum, Boriskino, Santa Cruz, Murray Felix, Lax&, Mokoia, Warrenton, Ornans TypeI+TypeIII = 2
_!
286
! 9.77
3.54
20.08 16.52
2.46 0.46
13.36 0.99
8.60 6.05
2.00
10.64
11.28
The chemiad .aompoaition of wme stony meteorite4
BOATO (op. cit.) report8 in many cases less water in the oarbonaceous chondritee than that found in the present investigation. BOATO used 8 combustiondistihetion method. Pennfield tubes were used in the present work with carefully dried PbO, 8s oxidant and trap for the sulphur. The material for analyses w8s the same as ~~OATO’S.The Pennfield method tends to give somewhat low values, and never too high ones, and the reeeon for the disagreement of the results is not olear. The relationship between all the meteorites of the high group seems to be as follows: 2. The carbonaceous 1. The oarbonaceous -Hfl. 8 ti chondrites of the chondrites of the org.m*tta l Cold Bokkeveld type (II) Orgueil type (I) n
--Haa
a.
a.0. l
uldcug.k?&tec
The tXrbOn8WSU8 ohondrites of the Felix type (or the omansites) (III)
4. The chondrites -0 + with 15-19 per cent metallic Fe
6. The enstatite
-0
b
chondrites of the Hvittis type
This is intended only to give a picture of the chemical relations between the subgroups, and not intended to suggest the genesis. There is insufficient evidence at the moment to permit any clear conclusions regarding the genesis of various groups of meteorites. The discontinuity in this series is interesting. The degree of oxidation, the T&le 4. MetAio Fe, weight 1 :aentintheHsndLgroupe+. AU determbtiona with the H & * NH&l emtracth method. Per cent met. Fe
Per oent met. Fe
ThUHpUp
mHgrmcpoorJd.
orguefi_
Hainaut
Imma Cold Bokkeveld Mighei NawIbpli H&ps8nticNz H-Y
MeY
Tromy Anrhus Rioh8rdton Fore& City Colbcipoli ochaMk o-72
oublui Llmo6
1.30 2.19
W8Ur%Ilt.QIl Ouidder WMlOnde F&x
4.02 4.37 4.71 4.72
:
l-heLfv-2, Monte dam Fortes Linum Holbrook Varpeiejlirvi MoKinney Mern
I
287
15*09 l&16 l&S9 17.30 17.41 18.29 16.30 19.14
6~86
6+N 7.05 7.63 7.81 &09
H. 33. WUK
water and aulphnr contenta, form well-defined ateps, and all the other component8 behave tdmilarly. To date, no example of any di%ae traaiti~ne from one subgroup to another have been found. Awxwdingly, the mineralogical composition muat also be of this d&continuous form. The only qnautitative mineralogical factor exsmkd here is the metallic iron-nickel content. !I%ia shows clearly the discontinuity in the degree of oxidation (Table 4). only the metallic Fe is recorded in tb table. The content of nickel ie &no& -n&ant. In Table 4 are to be found some stonee not listed in Tabkm 1 and 2. Only pa&al aua+m were made in these casea. It will be seen tirn the Table that there are disaontinnitiae in the st&ee of oxidation. A snrpriaing ferture is that the valuee seem to form an approximately geometric se&~. The group@ of the results around numbem 2, 4, and lt3 ptw cent may be q&e a&dent& certainly the number of results is ineticient fo merit any far-reaching oo~cluaion. The low group mema to have only on6 oxidation state. The Fe8 cxmteut is al80 very constant, and accxridingly alI the pointa repwaanting this group are gathered in a small area in F&J_ 1. It is surprising that only the high grnp exhibit8 variation in the &ate of oxid&ion, while the low group baa a co&ant oxidation state. l?urther invesfigation may chow greater variation in the low group than ie exhibited by the present ;reeulte. APPBNDEC
T~~~~~~~a~~~~f The composition of stony
SkmyAcfcwika. t3tmse-~m
Table I
meteoriteta. as praaoted in Table 1, abows the cations aa oxides, solphi* etc.’ This system is conventional, and do5 not in all cameagive a true rq53at5tation of 5iMrslogi~l facts. thccompmitio5beoat5athech5Jicaluufiaisdol5notfu5ishtbenan55ry For example, alI 8 is calculated to FcS, in spite of the Cwt that in msmy msteotitea there are emall sm0unt.e of (Ca, IyIn)8 (o1dbamit.o) and F&r@, (B), rml in cer~naceoun of “0rgar.W imlpbur. The amounta of tbae m&m&s would have chcndz+tae, evesIllmnuaznCMnt.0
tabelmowninordertopLaoepropealySsearellasCrand~ ThemimmQkNquantitetive analyiii~ is dii5cultto obtain. 0ldhatnite can be extract& with water. but the operation is ha&y quantitative because of the Mn content. CaO CM be found in &no& all waterertracts from
tiny metwritm, particukuly from the enstatite chontite. The author bebvea themfore that oldhsmite ia a far mom wmmon conutitu0nt in atony meteorites thub wm formerly euppowd. Phaxphorus is another element thst ia eqdy difficult to plaoe. If it ocours mxinly as schroibersite, (Fe, Ni, cO),P, it should be l&cd as P, but if it occurs as lllsnriljtd and/or apatite it should be listed as P,O,. Tha author bolicvcm that achmibemite scaroely ocouni in stony meteoritea There ere two reasons for this. (I} P forms mine5ls with Ca, Al, and Namuch more wily than it dcee with Fe, Ni. and Co, and therefore is exhausted before tbwe is an opportunity for schroibersite to form, Actually, schreihemite has been reported by cbemista dealing with Fe mete&tea; however, in%heae there is, of course, no Al. Ca, or Na. (2) Theauthor’s experience is that the amount of nickel extracted From the sample with F&Cl, * NE,Cl (the metallic Ni) is, within the liits of accuracy, always the snmc as the total Ni obtained fro5 the main analysis. Should schrcibersite occur, the total Ni would have to be greater. NiO can occur only when no ohondrites in which metallic Fe ia prcaent. This happens. for example, in the A there suw no me&&c Fe. Ni. Co tc extract, and accordingly we cannot make any aompariaon bedmen the metallic and the totat nickel. In this caec them is themfare no evidence to show whether schreibemite occurs or not. Anothc.* difhculty with Table 1 is the uncertainty in the oxidixed state of Fe. The amount of Fe0 is oniy a c&uh~ted number obtained by subtraction of the xnctdiic iron and the tmilite iron from the tote1 iron. The Fe8 tends to be, too high. becauwe aU S ~IU calculated to that compound. Acoordingly, the Fe0 tends to be too low. It is almost irnpamible to determine Fe0 288
dire&y. becwee of the pmaeameofnmdilyeohIbk9Nl~~~irm,orgeniccompour&. Whrnmtrgtodirroloetbs~farFeO~~imahrsduoedtoFd).~ thetowlironrrfb~tluntbetrasFeOieo~. (Tbemvll uxunmteofinminekomii ~~~MnddLahrsdin~~~~tbetotrlirondsterminsdtath~nraarrir aommhattoolor. Tbeoomott4~talimmirobtaimdfmmthe~ad*) Fe,Oo,&ouklbe ob~by~oTFd).Fe~rpdFeinFe8fnnnfhb~Mp.~~the lnfimhmetu0ht4mam~~lliC Fe0 L not known, the Fe,O, omn&bedetammdeifhsr. iron,f~~~guppacdmtfooomr. ~hkispdmblytm~~ ItiedSculttound~tJu ironebouldbefclrmdint&eediikentoxidstim8t&8inthermsstone. Wbenmeulkirar AotosUythaemeeam docmnot oeour. however, if~verypomibletbftberekeomeFe,O, fo~~~iptbb~oh~uindiarbdbytbsX-~yporder Tbeehwtalwpowdin~obopdrita petteun (Ih. uuy. privrb eommtim). (Kv~qp.cil.)aab,udlybewithoutfenictol,eitk. Itismastunf~tetb8tfsrrie ironeumotbedebrmmsd. rukefae&ul&iqtheminemlegkmleompo8itkmaf TlKrebDvebam8twnpt8to~ #tqT~&antbeobemimlM&we!& TklebwenotlmeQintendedtoqxaenttbe wimlmiaamt~ibmpaifiaa,butrkindof‘horm”for~ymsbori~ 8unhanoRphi~y
taomi&diugtQbeumdi&brlmumoftbs~inthspasntUiondthe~d
theeaenplio&edminen@yofmeteoritM. ItLinqNNiQJAeCommker ~ttbetnnemodewitboatknowingtheFe/Mgmtiofntbe~pymxsnaurd oliviass(tbsrJioiwttbb~ipbotb~~uruf~rappasd),~rithrd kIlowiqgtheloestionoftbef.kuld~wbinllwlwtfoundexobmk@iufek@=R must&awfombeevenlm?emi&ediq~~abpldedfmmigmoaBead~ mek~ by the C.I.P.W. w.
*-
abnlukmto
tiwrrm
A-1 winh to extend my gratitude to Dr. HAEOLD C. UEEY, rho wgge&ed a ulosar inva&igstion ofthe uarbonaoeoui~ahcmdritm. I am ales indebted to mrrny inutitutio~ and private pssnans for analytiaal mat&al, and for permkkm to um M yet unpublished ‘data. With Dr. GBO~~BEDWABDB and Mr. 0. Jomww of the Univemity of Chiaago, I had &uitfid dkwmions. I am indebted to Mr. E. P. HRTD~XSORfrom United Statea National Maream, and to Dr. C. R. NUSRB from U.S. Geologioal Swey, for aritiaally reading the nubnusuript. This rawan4k was supported by the Natiod 8cienoe Foundation.
Rarrrraare B-9 Boom Bo~x,
J. J. (1634) Ann. PM. ud Ckamie,a 113 G. (1964) &o&k. & Ce. Ada, 6.3OQ L. H., (1903) Butl. Corn. &ok de Fidamio No. 21 CHJusm, W. A. K. (1914) Beco& of the GeologioJ Survey of Jndk, 44.41 EDWABD~, G.. md UBBY, H. C. (1966) &mSes. slC_. A&z, 7, 164 Fs. H. W.. d oo.workem (lQ61) U.S. GeokgM Survey Bulletin No. QMJ tixsxrx, C. (1666) &-Z&r Akiui. IVia. Berlk, l, 346 KVABEA. L. 0. (lQ46) iUwok&xa, Aad. sd. fJ&!?R,4.63 LACEOIX.A. (1033) 0ompt. Rend, 1,661 Yhknxu~~,G. P. (1603) pmt. UB. Not. Afw. Wooh+tos, w 193 Ye9 G. P. (lSl6) #%oc. U76. Nat. Mw. Woakgkm. u, 109 Muxus~, G. (lQ63) QootSm. & Cm. Ado. 4,l NoED~~~~LD. A. E. (1676) Qod. F6rus. i &o&uk Fti.. 4,46 Pwor, C. T, end Eirr MAX H. (1963) CItrlogrre of Msteoritea Britii Mpmna UBXT, H. C.. cad CRUX. H. (lQ63) Qao&im. d Cwmochim. Ada. 4.36 WAEL, W. A. (1910) Z. amap. Ckm.. a 63 wAx& w. A. (lQ6oD) iuilb. iwag, se, 419 W~~~,W.A.(lQ6Ob)&mh+.~Comrodin.Ado,l,3O WAHL, W. A., end Wur. H. B. (lQ60) BuR. Carr. aed. de Pkkwwie. lao. 6 WAEL, W. A., uxi Wm. H. B. (lQ61) G%nnSm.d Ce. AC& t 134 Wm. H. B. (lQ4Q)Sec.Sci. Fems. Pm. Mdk.. 14.14 W~~HLI~ F..-urd HARRIS, E. P. (1660 UMI 1860)Sitt-Ber. AM. Wk. Wk. 86.6; II.666