Petrogenesis of low-Ti and high-Ti basalt, adakite and rhyolite association in the Peddavuru greenstone belt, eastern Dharwar craton, India: A Neoarchean analogue of Phanerozoic-type back-arc magmatism

Journal Pre-proof Petrogenesis of low-Ti and high-Ti basalt, adakite and rhyolite association in the Peddavuru greenstone belt, eastern Dharwar craton, India: A Neoarchean analogue of Phanerozoic-type back-arc magmatism Tarun C. Khanna, V.V. Sesha Sai

PII:

S0009-2819(20)30008-8

DOI:

https://doi.org/10.1016/j.chemer.2020.125606

Reference:

CHEMER 125606

To appear in:

Geochemistry

Received Date:

23 July 2019

Revised Date:

20 November 2019

Accepted Date:

26 January 2020

Please cite this article as: Khanna TC, Sai VVS, Petrogenesis of low-Ti and high-Ti basalt, adakite and rhyolite association in the Peddavuru greenstone belt, eastern Dharwar craton, India: A Neoarchean analogue of Phanerozoic-type back-arc magmatism, Geochemistry (2020), doi: https://doi.org/10.1016/j.chemer.2020.125606

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Petrogenesis of low-Ti and high-Ti basalt, adakite and rhyolite association in the Peddavuru greenstone belt, eastern Dharwar craton, India: A Neoarchean analogue of Phanerozoic-type back-arc magmatism

Tarun C. Khanna1* and V.V. Sesha Sai2

CSIR-National Geophysical Research Institute, Hyderabad-500007, India

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Geological Survey of India, Nagpur-440006, India

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*Corresponding author: [email protected]; [email protected]

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+91 40 27012488 (O); +91 9848240367 (Mobile)

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Highlights  We report coeval mafic-felsic magmatism in a Neoarchean greenstone terrane  The low- and high-TiO2 basalts are analogues to the Phanerozoic back-arc basalts  Rhyolite and dacite exhibit contrasting geochemical attributes  Dacites are analogous to the Phanerozoic adakites  We propose intraoceanic magmatism in a Neoarchean back-arc setting

Abstract

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The petrogenetic record, available in the literature, illustrating Neoarchean arc magmatic processes in a back-arc setting is rare. In this contribution, we present a comprehensive

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account of field, petrography and geochemistry of the Neoarchean bimodal mafic – felsic metavolcanic rock association in the Peddavuru greenstone belt, eastern Dharwar craton, India.

Basalt is the predominant rock type. Felsic volcanic rocks are interleaved with the basalts, in the central part. The basalts are fine grained, aphyric and essentially composed of amphibole and plagioclase with rutile, magnetite and ilmenite as accessory Fe-Ti oxide

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phases. The felsic volcanic rocks exhibit porphyritic texture. Based on the composition of the phenocryst type i.e. feldspar or quartz, two variants have been recognized. Biotite is present in subordinate amounts while, apatite and magnetite are the accessory phases. Basalts are tholeiitic in composition, whereas the felsic volcanic rocks are calc-alkaline in nature. On the basis of TiO2 contents, the basalts can be classified into low-Ti (< 1 wt. % TiO2) and high-Ti (> 1 wt. % TiO2) geochemical subgroups. The two subgroups, however, are consanguineous in nature. They display slightly depleted (La/Sm ~ 0.89) and mildly

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enriched (La/Sm ~ 1.44) chondrite normalized light rare earth element patterns (REE), and slightly depleted heavy REE (Gd/Yb ~ 1.2). On a primitive mantle normalized trace element variation diagram, irrespective of low- or high-Ti, the basalts display negative Nb and Ti

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anomalies, and zero to negative Zr-Hf anomalies relative to the neighbouring REE.

The felsic volcanic rocks are characterized by contrasting geochemical compositions. On

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the basis of high field strength element systematics, they are classified as dacites and

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rhyolites. Compared to the rhyolites, the dacites are characterized by high Mg# (39 ± 9 vs. 24 ± 5), low Nb (≤ 5 ppm vs. 14 ppm), Y (5.9 ± 1.8 ppm vs. 19 ppm) and Yb (0.47 ± 0.17 ppm vs. 1.72 ppm) contents. Further, the dacites exhibit comparatively steep chondrite normalized

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REE patterns (LaN/YbN ~ 30 vs. 10) with negligible to slightly positive Eu anomaly (Eu/Eu* = 0.9-1.2 vs. 0.6). On a primitive mantle normalized trace element variation diagram they

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exhibit negative Nb and Ti anomalies, similar to the rhyolites, but contrasting positive Zr-Hf

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peaks and high Zr/Sm ratio (73 ± 18 vs. 24). The trace and rare earth element attributes of these dacites are identical to the adakitic rocks that have been recognized from the Phanerozoic intraoceanic arcs. On the contrary, rhyolites are the partial melt products involving minor plagioclase fractionation that are generated beneath the arc crust under extension.

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Overall, the chemical compositions of the mafic and felsic volcanic rocks in the Peddavuru belt indicate that interaction with the Archean upper continental crust, magma mixing and/or assimilation and fractional crystallization processes cannot be the cause of these geochemical patterns. The attributes instead reflect primary mantle source characteristics. MORB-like trace element signatures in combination with arc-like geochemical affinity in the Peddavuru basalts, provides compelling evidence of their origin in an intraoceanic back-arc setting. Accordingly, the Peddavuru greenstone belt presents a

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Neoarchean analogue of Phanerozoic-type back-arc magmatism.

Keywords: Back-arc basalt, adakite, rhyolite, Peddavuru greenstone belt, eastern Dharwar

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craton, India

1. Introduction

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The early depleted (~3.8 Ga; Hoffmann et al., 2010) mantle reservoirs provide significant constraints for how much sooner in time did the Earth transitioned from stagnant lid (O’Neill

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and Debaille, 2014) to modern day subduction-type plate tectonic processes. The evidence available in the published literature, nevertheless, suggests that the onset of Wilson cycle and

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initiation of subduction-related plate tectonic processes were in vogue at least by 3 Ga (e.g.

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Smithies et al., 2005; Shirey and Richardson, 2011; Szilas et al., 2012, 2016; Khanna et al., 2018). Globally, ~2.7 Ga has recorded a peak in the growth of continental crust formation via terrane accretion and amalgamation. The relicts of thus accreted terranes consist of either komatiite-tholeiite sequences resulting from mantle plumes, and/or tholeiitic to calc-alkaline basalt, andesite, dacite and rhyolite associations representing the products of arc magmatism. The evidence related to such processes is well preserved in the Neoarchean greenstone belts

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of the Superior Province, Canada (e.g. Polat et al., 1998; Polat and Kerrich, 2006), the Dharwar craton, India (e.g. Manikyamba and Khanna, 2007; Manikyamba et al., 2008), and elsewhere on the Earth. Unlike in the Phanerozoic arc systems e.g. Izu-Bonin-Mariana (e.g. Elliott et al., 1997; Pearce et al., 2005; Reagan et al., 2010), the geochemical record available in the literature signifying the petrogenesis of basalts in a Neoarchean back-arc setting is quite limited (e.g. Manya, 2004, 2016; Manya and Maboko, 2008; Kerrich et al., 2008; Manikyamba et al., 2009; Khanna et al., 2015).

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The greenstone belts in the eastern Dharwar craton (EDC) are predominantly of Neoarchean age (∼2.7 Ga; e.g. Jayananda et al., 2013). Some of the major greenstone belts

such as Gadwal (Manikyamba et al., 2005, 2007; Manikyamba and Khanna, 2007; Khanna,

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2013; Khanna et al., 2013, 2014), Veligallu (e.g. Khanna et al., 2015, 2016; Dey et al., 2018), Hutti (e.g. Sarma et al., 2008; Manikyamba et al., 2009), Sandur (e.g. Manikyamba et al.,

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2008; Ram Mohan et al., 2013), Kushtagi (e.g. Naqvi et al., 2006), Kolar (e.g. Rajamani et

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al., 1985; Balakrishnan et al., 1990), Ramagiri (e.g. Zachariah et al., 1996), Penakacherla (e.g. Manikyamba et al., 2004) and Kadiri (e.g. Dey et al., 2013; Manikyamba et al., 2015) have been extensively studied in relation to their economic potential, petrogenesis and

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geodynamics, which provide significant insights into the nature of magmatic processes and growth of continental crust in the eastern Dharwar craton, India (Jayananda et al., 2018).

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Comparatively, the Peddavuru greenstone belt remains as one of the least studied terranes

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in the eastern Dharwar craton. To our knowledge, there is no significant published literature that provides a detailed account of the petrogenetic processes explaining the evolution of this greenstone belt. In this contribution, we provide a comprehensive account of field, petrography and geochemistry of the mafic and felsic volcanic rock association comprising of low- and high-Ti basalts, and a Na-rich dacite – rhyolite suite. Further, we will show that (1) on the basis of HFSE systematics, the basalts can be distinguished into two consanguineous

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geochemical subgroups, (2) rhyolites are not the fractionation products of dacites. Instead, the felsic volcanic rocks evolved as two independent magma series, (3) the mafic and felsic volcanic rocks are devoid of any crustal contamination signatures, and presumably erupted in an oceanic setting, and (4) the geochemical attributes of the basalts are identical to those generated in the Phanerozoic back-arc basins. Therefore, we relate their petrogenesis in response to subduction related magmatic processes in a paleo back-arc tectonic regime in the Neoarchean.

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2. Regional geology 2.1. Dharwar craton

The Dharwar proto-continent is subdivided into three distinct cratonic blocks: the western

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Dharwar craton, the eastern Dharwar craton, and the southern granulite terrane (Swami Nath and Ramakrishnan, 1981). The western and eastern sectors of the Dharwar craton comprise of

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laterally extensive and linearly arcuate Mesoarchean and Neoarchean greenstone terranes

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surrounded by gneisses and granitoids. The NNW-SSE trending shear zone, extending along the eastern margin of the Chitradurga greenstone belt (Fig. 1A, B; Naqvi and Rogers, 1987), separates the eastern greenstone belts from those in the western sector of the Dharwar craton.

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On the basis of stratigraphy, two temporally distinct categories of greenstone belts have been recognised in the western Dharwar craton (Ramakrishnan et al., 1976; Naqvi and Rogers

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1987). The older Sargur group consists of gneisses and volcano sedimentary units of

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Paleoarchean age (e.g. Beckinsale et al., 1980; Nutman et al., 1992; Peucat et al., 1995). The comparatively younger Dharwar Supergroup unconformably overlies the Sargur group. The Dharwar Supergroup is further subdivided into lower Bababudan group of Mesoarchean age and an upper Chitradurga group of Neoarchean age (Anil Kumar et al., 1996). In contrast, the eastern Dharwar craton essentially consists of granites and volcanic sequences of Neoarchean age (e.g. Nutman et al., 1996; Balakrishnan et al., 1999; Rogers et al., 2007; Jayananda et al.,

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2013; Khanna et al., 2014, 2016). For an elaborate reading on the stratigraphy, structure and lithological information the reader is referred to (Jayananda et al., 2018). 2.2. The Peddavuru greenstone belt The study area (Fig. 1B), the Peddavuru greenstone belt, is in the eastern Dharwar craton and it is situated to the north of the Cuddapah Basin. The northern and the central parts of the belt are surrounded by younger granites of ~2.5 Ga age (Crawford, 1969). The southern part of the belt tapers beneath the Proterozoic sedimentary cover of the Cuddapah Basin. The

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Peddavuru greenstone belt (Fig. 1C) exhibits NW-SE trend with an approximate strike length of ~ 40 km extending from Jugudem in the north to Ethipothala in the south. It has a maximum width of ~ 2.5 km in the central part (Srinivasan and Krishnappa, 1991).

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Peddavuru greenstone terrane predominantly consists of mafic and felsic volcanic sequences. Banded Iron Formations extend all along the eastern margin of the terrane, proximally

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associated with the basalts (Fig. 1C). The belt is surrounded by granitoids and intruded by

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younger mafic dikes. The magmatic intrusions are dolerite, pyroxenite and gabbro. Some of the intrusions are disposed parallel to the regional foliation. The belt has been subjected to two generations of folding, and metamorphosed under low grade amphibolite facies

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conditions. Hence, the term ‘meta’ is implicit to the lithologies in this belt. The rock units show NNW-SSE isoclinal folds (F1) with northerly plunges, which are refolded (F2) into

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NNW-SSE antiformal synclines with relatively steep plunges to south (Srinivasan and

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Krishnappa, 1991). The terrane predominantly consists of mafic volcanic rocks (Fig. 2A), whereas, the felsic volcanic sequences occur as linear outcrops interleaved with the mafic horizons in the central part of the belt (Figs. 1C, 2B). At some locations the metabasalts show variably deformed pillow structures (Ramam and Murty, 1997). The felsic volcanic rocks show NNW foliation trends, and sampled from elsewhere in this belt yielded a SIMS U-Pb zircon age of ca. 2.4 Ga (Jayananda et al., 2013). A four point whole-rock Rb-Sr isochron

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yielded an age of 2.551 ± 19 Ma (Rajamanickam et al., 2014). On the basis of previous geochronological studies carried out in the greenstone belts of the eastern Dharwar craton, for instance, Ramagiri (Zachariah et al., 1995), Hutti (Rogers et al., 2007), Kolar (Balakrishnan et al., 1999), Gadwal (Khanna et al., 2014) and Veligallu (Khanna et al., 2016), which yielded a ~ 2.7 Ga age for the metavolcanic rocks in these greenstone belts, As a corollary, it endorses a Neoarchean age for the volcanic rocks in the Peddavuru greenstone belt. 3. Sampling and analytical techniques

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The volcanic rocks sampled for this study were collected from relatively fresh portions of the outcrop devoid of quartz veins and secondary mineralization. The samples were

systematically collected, labelled in an incremental fashion, starting from the northern part of

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the belt near Jugudem (N16°48ʹ42ʺ E79°06ʹ01ʺ; EPB-1/J; Table 1, 2) towards the south-west of the Nagarjuna Sagar (N16°36ʹ31.6ʺ E79°17ʹ41.2ʺ; EPB- 164/NS; Table 1). Petrographic

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screening was performed for secondary carbonate and sulphide mineralization, intense

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mineralogical alterations, and the preservation of igneous textures. The rocks were further screened for loss on ignition (LOI). The sample powders weighing 1 gram each were taken in pure quartz crucibles and heated in a muffle furnace for ~2 hours at 900° C temperature. The

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loss on ignition values are ≤ 1 wt. %. A representative subset consisting of 72 samples (48

studies.

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mafic volcanics + 24 felsic volcanics), was then selected for further detailed petrological

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For bulk-rock geochemistry, rocks were powdered manually using an agate mortar and pestle. All the geochemical analyses were performed at CSIR – National Geophysical Research Institute, Hyderabad, India. Ten major element oxides were analyzed using pressed powder pellets, on a Philips MagiX PRO PW2440; microprocessor controlled, wavelength dispersive sequential XRF following the procedures described in Krishna et al. (2007). The relative standard deviation for the major element oxides is < 3%. Trace elements including

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large ion lithophile elements (LILE), high field strength elements (HFSE) and rare earth elements (REE) were determined by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS; Nu Instruments Attom, UK). The instrument operating parameters and sample dissolution procedures are described in Khanna et al. (2015). In brief, 50 mg of finely ground sample powder was digested in a freshly prepared mixture of ultrapure HF and HNO3 at 3:1 ratio, in screw top Teflon "Savillex" vessels, and heated on a hot plate at 160°C. Certified reference materials BHVO-1, BIR-1, JR-1 and JR-2 were

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dissolved simultaneously and analyzed along with the samples. Oxide and oxy-hydroxide ratios were low (< 0.2%) and the doubly charged ions ratio was < 3%. Mass bias

fractionation and isobaric interferences were addressed by using certified geochemical

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reference materials, while the external drift correction was performed by repeated analyses of BIR-1 and JR-2. Precision and accuracy are better than RSD 3% for the majority of the trace

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elements (Table 3). The trace and rare earth element concentrations determined for BHVO-1,

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BIR-1, JR-1 and JR-2 are in concurrence with the recommended values in the GEOREM database.

4.1. Petrography

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4. Results

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Detailed petrographic study of the mafic metavolcanic rocks of the Peddavuru schist belt indicate that the metabasalts are fine grained, aphyric and essentially composed of green

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amphibole and plagioclase with rutile, magnetite and ilmenite as accessory Fe-Ti oxide phases. Amphibole in plane polarised light is pleochroic in shades of pale green and in few grains two sets of cleavage characteristic of hornblende are observed. Plagioclase is confined to the groundmass. The rock exhibits development of planar fabric in the form of foliation (Fig. 3A). Preferred alignment of the greenish amphiboles defines the planar fabric noticed in the rock. Plagioclase that occurs in between the amphibole is relatively unaltered and exhibits

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lamellar twinning. Observation under higher magnification indicates that rutile is euhedral, reddish in colour and exhibits high relief under plane polarized light (Fig. 3B). Such rutile is noticed amidst pale greenish amphibole that are prismatic in nature. Magnetite is noticed as fine subhedral disseminations (Fig. 3C), which is consistent with its late stage crystallisation. At few places, it is observed that the euhedral ilmenite grains are surrounded by reddish rutile. The felsic metavolcanic rocks exhibit porphyritic texture. Based on the composition of

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the phenocrysts two variants are distinguished. In the first variant, quartz phenocrysts are prominently seen while feldspar phenocrysts are conspicuous in the second variant. Fine

grained admixture of quartz, feldspar and muscovite are observed in the first variant with

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quartz as the phenocryst phase (Fig. 3D). Quartz phenocryst in crossed nicols exhibit low

order greyish interference colour and undulose extinction. In the second variety the feldspar

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phenocrysts are set-in a fine grained groundmass consisting of quartz, K-feldspar and

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plagioclase. Among the feldspar phenocrysts it is observed that plagioclase is the dominant phase. Plagioclase phenocrysts under crossed nicols exhibit conspicuous lamellar twinning (Fig. 3E). Feeble sericitization is noticed in such plagioclase phenocrysts. Observation under

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crossed nicols under higher magnification indicates that in some feldspar phenocrysts the twin lamellae are not parallel and the relatively broader darker domains in such grains show

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feeble development of tartan twinning, which is a characteristic feature of K-feldspar (Fig.

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3F). Flaky brown biotite is aligned along a mildly developed planar fabric. Apatite and magnetite are the accessory phases. Apatite is noticed as euhedral prismatic grains (Fig. 3G, H), whereas minute grains of magnetite are noticed as euhedral to subhedral disseminations in the groundmass. Overall, the petrographic studies consistently indicate that the Peddavuru volcanic rocks were metamorphosed under lower amphibolite facies condition. 4.2. Geochemistry

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The major element oxides were recalculated to 100% anhydrous for inter-comparison purpose. Mg# is calculated as the mole ratio of Mg/ (Mg + Fe2+), where Fe2+ is assumed to be 90% of the total Fe. The selected trace elements and the rare earth elements (REE) are normalized to chondrite and primitive mantle using the values of Sun and Mc Donough (1989), and indicated by (N) and (PM) subscripts, respectively. The mafic volcanic rocks consist of 47 – 52 wt. % SiO2 and have a broad range in their MgO (6 – 10 wt. %), TiO2 (0.61 – 1.66 wt. %), Fe2O3 (12.7 – 18.7 wt. %), Mg# (42 – 62), Nb

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(1.9 – 5.4 ppm), Zr (35 – 104 ppm), and Y (17 – 32 ppm) contents (Table 1). On a chondrite normalized rare earth element diagram (REE) the rocks consistently display mildly enriched light-REE (Fig. 4A, B; LaN/YbN = 0.95 – 1.8) patterns. On a primitive mantle normalized

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trace element variation diagram, the rocks exhibit both negative and feeble positive Zr-Hf

anomaly (Fig. 4C, D). Collectively as a group, they display negative Nb and Ti anomalies.

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Like the mafic volcanic rocks, the felsic volcanic rocks display extreme range in their

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major element oxide concentrations and trace element contents. For instance, the SiO2 concentrations in the felsic volcanics range from 66 to 74 wt. % with a wide variation in their TiO2 (0.05 – 0.35 wt. %), Mg# (19 – 48), Nb (3.3 – 15.6 ppm), Zr (81 – 155 ppm), Y (4 – 22

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ppm) and Yb (0.3 – 1.8 ppm) contents. On a chondrite normalized REE diagram (Fig. 4G, H), they display coherent, fractionated patterns with enrichment in the light-REE and depletion in

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the heavy-REE, and negative to slightly positive Eu anomaly. On a primitive mantle

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normalized trace element variation diagram, the rocks exhibit negative Nb and Ti anomalies, and feeble negative to strong positive Zr-Hf anomaly (Fig. I, J). On bivariate diagrams involving major and trace elements (Fig. 5), the mafic and the

felsic volcanics plot as distinct clusters, which is consistent with the bimodal nature of the rocks. In the trace element bivariate diagrams (Fig. 5E-H), the felsic volcanics plot as two separate groups with contrasting trace element signatures. On the basis of petrographic

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studies, major element concentrations, high field strength element systematics (HFSE; Nb, Zr, Y) and the REE, the felsic volcanic rocks can be initially categorized into: type I and type II (Rajamanickam et al., 2014). The type I felsic volcanic rocks consists of plagioclase as the phenocryst phase (Fig. 3E), whereas the type II felsic volcanics are represented by quartz phenocrysts (Figs. 3D and F). Further, in contrast to the type I felsic volcanics (Figs. 5A-H), the type II consist of comparatively high SiO2, Nb, Th, Y, REE (Ce and Yb), and relatively low TiO2, Al2O3, FeO*, Zr, and relatively less fractionated heavy-REE and exhibit negative

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Eu anomaly (Fig. 4H). Discussed further later in the text. 5. Discussion 5.1. Alteration and trace element mobility

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The rocks that occur in the Archean greenstone terranes underwent geochemical

alteration and post-magmatic metamorphic processes, and hence, an assessment of the extent

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of trace element mobility is critical prior to the petrogenetic interpretation of such rocks. The

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studies in the past (e.g. Polat and Hofmann, 2003) have shown that the elements Rb, Sr, Cs, Ba, K, Na, Ca, Fe, and P, are alteration sensitive and could be mobilized during postmagmatic crystallization, and metamorphism. Therefore, these elements have not been

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extensively used to derive the first order interpretation regarding the genesis of the Peddavuru volcanic rocks. Instead, the elements that are least susceptible to mobility during alteration

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and metamorphism up to amphibolite facies i.e. Al, Ti, Cr, Ni, Sc, V, Nb, Ta, Zr, Hf, Th, Y,

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and the heavy-REE have been considered suitable, and accordingly the geochemical diagrams involving these elements have been used for the petrogenetic interpretation of the Peddavuru volcanics. Further, the coherent display of REE and trace element patterns (Fig. 4) without any obvious Ce anomalies (e.g. Polat et al., 2003), is taken as evidence that the light-REE were not significantly mobilized during post-magmatic alteration and low grade amphibolite facies metamorphism. Furthermore, the robust correlations between Nb and Zr, Ce and Y in

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the Peddavuru mafic rocks (Fig. 5E-G) suggest insignificant trace element mobility. Therefore, the relative depletions and enrichments in trace elements of the individual rock groups are taken to reflect their primary magmatic source characteristics. 5.2. Classification Using the immobile trace element diagram of Winchester and Floyd (1977), the mafic and the felsic volcanic rocks sampled for this study are classified as basalt, dacite and rhyolite, respectively (Fig. 6A). The type I felsic volcanic rocks, as discussed above, are identified as

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dacites, and rhyolites represent the type II. The basalts are tholeiitic in composition (Fig. 6B). The dacites and rhyolites are calc-alkaline in nature (Fig. 6B). On the basis of TiO2

concentrations, the Peddavuru basalts can be further categorized into two populations; low-Ti

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(< 1 wt. %) and high-Ti (> 1 wt. %) groups (Table 1). The low-Ti basalts are generally

characterized by low FeO*, high MgO, Cr and Ni contents (Fig. 7A-C). They extend to

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relatively higher Al2O3/TiO2, CaO/TiO2, and lower Ti/V and Ti/Sc ratios, compared to the

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high-Ti basalts (Fig. 7D-F). Discussed further later in the text. 5.3. Testing for crustal contamination, magma mixing, assimilation and fractional crystallization (AFC)

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Regardless of volcanic (e.g. rhyolite) or plutonic (e.g. granite) in nature, the geochemical attributes of these felsic rocks, in general, appear to be similar, and hence, it is difficult to

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appreciably identify the involvement of continent derived crustal components in the source of

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felsic lavas. For instance, the major and trace element compositions in the Peddavuru rhyolites are similar to that in the Archean Upper Continental Crust (Fig. 5A-H; AUCC; Rudnick and Gao, 2004). Therefore, the felsic volcanic rocks in the Peddavuru greenstone terrane may not be suitable candidates to test for crustal contamination signatures. On the contrary, basalt can be used as a robust endmember, which is sensitive to the effects of crustal contamination, magma mixing, and AFC processes, if any, during its emplacement at the

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crustal levels. Therefore, the geochemical composition of the basalt has been used as a proxy to test for any potential crustal input in the mantle source of the Peddavuru volcanics. During MORB melting, Ti and Zr are not significantly fractionated (Hatton and Sharpe, 1989) and therefore, the Ti/Zr ratio in the lavas should closely reflect that of their mantle source. Rationale is that during formation of the continental crust, Ti behaves as a compatible element in a Ti-bearing oxide phase (e.g. magnetite or ilmenite; Condie, 1981). In contrast, Zr behaves as an incompatible element. Therefore, melting or assimilation of crustal rocks

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should lead to an enrichment of Zr relative to Ti in the resulting melts, and result in low Ti/Zr ratios in the basalts. On a Ti vs. Zr bivariate diagram (Fig. 8A), the Peddavuru basalts with Ti/Zr ~ 114 ± 50 tightly cluster around the MORB mantle array and therefore, inconsistent

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with the involvement of a low Ti/Zr crustal component (Ti/Zr = 20; Rudnick and Gao, 2004) in their mantle source. Moreover, the decreasing MgO contents in the Peddavuru basalts do

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not show any correlation with the enriched light-REE (Fig. 8B), as would be expected in case

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of crustal contamination. Instead, the basalts exhibit a narrow range in their (La/Sm)N = 0.81 – 1.4 and plot within the compositional field observed in the modern day MORBs (Gale et al., 2013).

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Crustal contamination would thus lower the Nb/Th ratio of the erupted melt compared to a pristine melt derived from the upper mantle (Jochum et al., 1991). Conversely, it results in

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high Th/Ce similar to that in the continental crust (Th/Ce = 0.17; Rudnick and Gao, 2004).

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Although there is evidence of Mesoarchean upper crust in the eastern Dharwar craton (Maibam et al., 2011), to a first order, the depletion in Nb relative to the REE and Th in the Peddavuru basalts (Fig. 4C, D) may then reflect a crustal contamination signature. The Nb/Th ratio in the Peddavuru basalts ranges from 3 to 9 with a mean value of 6, which is close to the primitive mantle value of 8 (Sun and McDonough, 1989), and considerably higher than that in the Archean Upper Continental Crust (Fig. 8C; AUCC; Nb/Th = 1.14; Rudnick and Gao,

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2004). The Th/Ce ratio in the Peddavuru basalts is ~0.05, which is significantly lower than that in the continental crust (Fig. 8D), and identical to the basaltic melts derived from the upper mantle regions (Th/Ce = 0.01 – 0.06; Gale et al., 2013). Further, in SiO2 versus major element oxide variation diagrams (Figs. 5A-D), the Peddavuru basalts do not plot on a mixing line between the average MORB mantle and the continental crust. Therefore, any interaction or mixing between the melts derived from the upper mantle and the crustal components is reasonably ruled out. Furthermore, it does not

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support mixing of magmatic melts between the sources of Peddavuru basalts and the rhyolites. Further, assimilation and fractional crystallization of felsic upper continental crust by ascending mafic melts cannot account for the trace element contents observed in the

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Peddavuru basalts (Figs. 5E-H), which is again similar to that observed in the Phanerozoic MORBs. Most importantly, the trace element concentrations observed in the Peddavuru

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dacites and rhyolites cannot result due to magma mixing or assimilation and fractional

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crystallization of felsic upper crust by ascending mantle melts. The Nb, Y and Yb contents in the Peddavuru dacites are much lower, and the Mg# is significantly higher than that in the continental crust. Moreover, the positive Zr -Hf anomaly,

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apparent in these samples, is not a ubiquitous feature of the continental crust. The high Zr/Sm in these dacites is consistent with the incompatibility of Zr in amphibole that remains as a

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residual phase during partial melting of a low-Mg amphibolite source (Drummond et al.,

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1996; Foley et al., 2002), discussed further later in the text. Therefore, the geochemical attributes do not support crustal contamination, magma mixing and / or assimilation and fractional crystallization of the felsic upper crust by the ascending mantle melts. Hence, the Peddavuru volcanics did not erupt through the continental crust. 5.4. Petrogenesis

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The trace element systematics rather suggest that the Peddavuru volcanics erupted in an oceanic setting. The basalts that erupt at mid-ocean ridges are generally characterized by depleted light-REE patterns, and devoid of any negative Nb or Ti anomalies (Fig. 4E, F; Hofmann, 1988). Similarly, the ocean plateau basalts (OPBs; e.g. Fitton and Godard, 2004), which originate from mantle plumes are typically characterized by (1) depleted to flat lightREE patterns (Fig. 4E), (2) Nb/Th ratio greater than the primitive mantle value of 8, and (3) zero to positive Nb, Zr and Ti anomalies (Fig. 4F). In contrast, the Peddavuru basalts have

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low Nb/Th ratios, slightly fractionated REE patterns with negative anomalies at Nb, Zr and Ti (Fig. 4C, D). Therefore, an origin from a plume impregnated mantle source does not appear to be a suitable hypothesis.

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The negative Nb anomaly is a characteristic feature of the continental crust. As discussed above, crustal interaction is not a viable option. Alternatively, the negative Nb anomaly is

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recognized as an essential attribute of magmas generated in subduction-related arc settings

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(Pearce and Peate, 1995). On the basis of the screening parameters given by Condie (1989): 0.1 < Th/Yb < 0.3, Th/Nb (> 0.07), Nb/La (≤ 0.8), Hf/Th (< 8), Zr/Y (< 3), Ta/Yb (≤ 0.1) and Ti/Zr (≥ 85), the Peddavuru basalts qualify as island arc tholeiites, and for that reason, in the

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Nb/Y vs. Ti/Y discrimination diagram they overlap the mid ocean ridge basalts (MORB) and plot in the volcanic arc field (Fig. 9A; Pearce, 1982). Further, the Peddavuru basalts display

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REE and trace element patterns identical to the Phanerozoic intraoceanic arc basalts (Fig. 4;

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Elliott et al., 1997; Pearce et al., 2005). The low Ce/Yb trend defined by the Peddavuru basalts is identical to the basalts generated in the Phanerozoic island arcs (Fig. 9B). Apparently, the geochemical attributes are consistent with an intraoceanic subduction-related origin for the volcanic rocks in the Peddavuru greenstone terrane. The chemistry of the island arc magmas, in principle, is controlled by the contributions from two geochemically distinct mantle sources i.e. the mantle wedge, and the melts

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generated from the subducted slab. The degree of depletion in the heavy-REE is controlled by residual garnet in the source, which is quantified by Gd/Yb ratio. For instance, the (Gd/Yb)N in the basalts is ~1.1 to 1.3, which is lower than that in the rhyolites (Gd/Yb)N ~1.3 to 1.7. In contrast, the dacites are characterized by much higher (Gd/Yb)N ~1.8 to 3.6. This indicates that the individual rock units were generated from variable depths, and presumably from different sources in the sub-arc mantle. 5.4.1. The mantle wedge component

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The high field strength elements (Nb, Zr) as well as the REE, Y, Ti, V and Sc, are least soluble in aqueous fluids. The depletion of HFS elements relative to the LILE and the lightREE in arc magmas has therefore been attributed, at least in part, to slab-related fluid

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enrichments (Woodhead et al., 1993), and as a consequence the HFS elements are primarily contributed to the magma by the mantle wedge (Condie, 2005). As such, the HFSE

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concentrations and their interelement ratios in magmas reflect the composition of the sub-arc

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mantle and, therefore, can be used as tracers to infer the nature of the mantle source. The unfractionated middle to heavy-REE chondrite normalized patterns (GdN/YbN ~ 1) in the Peddavuru basalts are consistent with partial melting in the upper mantle at a shallow

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depth in the spinel stability field, which is comparable to the source of normal MORBs (e.g. Gale et al., 2013). The Ti/V ratios in the Peddavuru basalts is ~20, which is identical to the

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range observed in the Lesser Antilles arc lavas (Macdonald et al., 2000), and slightly depleted

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compared to the normal MORB (Ti/V = 25.4; Pearce and Parkinson, 1993). The Zr/Y ratio in the Peddavuru basalts is ~ 1.4 to 3.5 with an average value of ~2.5, which is similar to that observed in the normal arc system (Zr/Y ~ 3.3; Stern et al., 2003), but extends to relatively more depleted values than that in the average N-MORB (Zr/Y = 2.6; Sun and McDonough, 1989). The Ta/Nb in the Peddavuru basalts is ~0.068, which is similar to the ratio in the average N-MORB (0.06; Sun and McDonough, 1989). These geochemical factors suggest

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that the Peddavuru basalts were generated from partial melting of a depleted mantle source, which had experienced previous melt extraction events, presumably in a back-arc basin or at a mid-ocean ridge (Woodhead et al., 1993). The Nb contents in the arc magmas are generally < 2 ppm (Elliott et al., 1997). Further, the arc magmas are characterized by very low Nb/Yb ratio ~0.48 compared to the average NMORB (Nb/Yb = 0.76; Sun and McDonough, 1989). This is consistent with their generation from necessarily depleted mantle sources. By comparison, the Peddavuru basalts consist of

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relatively high Nb (1.9 – 5.4 ppm; Table 1) and span high Nb/Yb (0.86 – 1.78) relative to the N-MORB, which suggests that the mantle source of the Peddavuru basalts is enriched in Nb relative to the source of normal MORB, but comparable to that observed in the basalts

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generated in the back-arc basins (Nb = 0.98 – 7.7 ppm, Nb/Yb = 0.49 – 2.5; Pearce et al.,

2005). Such Nb-enriched nature can possibly be ascribed to: (1) a plume-modified mantle

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wedge; (2) partial melting of an Nb-enriched mantle wedge in the sub-arc mantle; or (3) low

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degree partial melting of a depleted MORB mantle source. As discussed earlier, a plumemodified mantle wedge cannot explain the geochemical attributes of the Peddavuru basalts. The partial melting of an Nb-enriched mantle wedge in the sub-arc mantle produces Nb-

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enriched basalts and high Nb basalts (7 – 16 ppm, Sajona et al., 1996; and > 20 ppm, Reagan and Gill, 1989, respectively). The Peddavuru basalts are neither characterized by high

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absolute Nb contents nor high Zr/Y ratios and fractionated REE and trace element patterns

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typical of NEBs. Therefore, it is unlikely that they were generated from an Nb-enriched mantle source. A non-modal batch melting model using the formula, CL/C0 =1/ (D0 +F (1−P)) (Shaw, 1970) is examined here; where CL = the concentration of a trace element in the liquid, C0 = the concentration of a trace element in depleted MORB, D0 = bulk partition coefficient for a trace element with respect to depleted MORB source, F = degree of partial melting, P = bulk partition coefficient for a trace element in the melt. The modelled parameters for source

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composition; melt proportions, and mineral/melt partition coefficients were adopted from McKenzie and O’Nions (1991, 1995) and are described in the figure caption (Fig. 10). It is shown that moderate to relatively low degree ~ 15 % – 9 % partial melting of a depleted MORB source can reasonably explain the observed range in the HFSE concentrations of the Peddavuru basalts (Fig. 10). 5.4.2. Negative Zr-Hf anomaly and low Zr/Sm ratio in the Peddavuru basalts Regardless of low- or high-Ti attribute, a part population of the Peddavuru basalts

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exhibits prominent negative Zr-Hf anomalies relative to the middle-REE (Fig. 4D) and low Zr/Sm ~ 17 ratio compared to the primitive mantle (Zr/Sm = 25; Sun and McDonough,

1989). The remainder of the population have zero to slightly positive Zr-Hf peaks and extend

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to slightly higher Zr/Sm ~ 30 ratio relative to the primitive mantle (Fig. 4C). Such

Zr(Hf)/middle-REE fractionation in the source of the basaltic magmas has been partially

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ascribed to reflect: (1) segregation of a magmatic melt at greater depth (> 400 km) with

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majorite garnet in the residue of a mantle plume resulting in negative Zr (Hf) anomalies; or segregation of a melt at a shallow depth, with accumulated Mg-rich perovskite, or residue at depths > 700 km in the source of a mantle plume to produce positive Zr (Hf) anomalies (Xie

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et al., 1993); (2) a heterogeneous mantle source stemming from two stage partial melting of a mantle wedge to account for both positive and negative Nb and Hf anomalies in arc basalts

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(Pearce et al., 1999; Hollings and Kerrich, 2004).

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The Peddavuru basalts are characterized by (Gd/Yb)N ratio ~1.15, which is close to the lower limit observed in the MORBs (0.8 to 1.6; Gale et al., 2013). A mantle plume derived melt with garnet in its source residue, irrespective of its segregation at a shallow level or from a greater depth, it will yield significantly higher (Gd/Yb)N ratios > 1 e.g. ocean island basalts (GdN/YbN = 3; Sun and McDonough, 1989). Therefore, as discussed above, melting of a plume mantle source cannot explain the geochemical signatures observed in the Peddavuru

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basalts. Hollings and Kerrich (2004) have invoked a two stage melt extraction model to account for the negative and positive Nb and Hf anomalies observed in the tholeiitic basalts of the Pickle Lake greenstone belt. It has been proposed that first stage partial melting of a mantle wedge in the sub-arc mantle generates melts with enriched light-REE relative to the HFSE (Nb, Hf and Ti), leaving a complimentary residue depleted in light-REE and enriched in Nb, Hf and Ti. Therefore, partial melting of the residual mantle subsequently produces melts with positive HFSE anomalies. Although this model may partially account for the

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negative Nb, Hf and Ti anomalies, it does not explain the contrasting combination of negative Nb anomaly and positive Zr-Hf anomalies in some of the basalts of this study. Moreover, the basalt samples with Hf/Hf* > 1 do not exhibit depleted light-REE patterns, which is supposed

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to be present in the melts that are subsequently produced from the residue.

Mantle metasomatism by partial melts derived from upper continental crust (UCC) in the

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source of back-arc magmas, appears to be a competing hypothesis that has been recently

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proposed to explain the petrogenesis of basalts in the Southern Volcanic Zone, Argentina (Holm et al., 2016). The basalts thus produced are characterized by negative Zr-Hf anomaly and low Zr/Sm ratio relative to the primitive mantle. These basalts are further characterized

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by relatively high Th/Ce ~ 0.11 compared to the primitive mantle (0.05), and extremely low Zr/Th ~ 19 ratio similar to that in the Archean UCC (Rudnick and Gao, 2004). On the

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contrary, some of the Peddavuru basalts, although exhibit negative Zr-Hf anomaly and low

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Zr/Sm ratio, the Th/Ce (0.05) is identical to the primitive mantle value and Zr/Th (~102) is significantly higher than that in the continental crust. Thus, it is unlikely that subducted sediment or pre-existing continental crust may have significantly contributed in the genesis of Peddavuru basalts. The Peddavuru basalts are characterized by uniform Zr/Hf ratio of 36 ± 2, which is identical to the primitive mantle value of 36 (Sun and McDonough, 1989). Further, the robust

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correlation between Zr and Hf (r = 0.998; figure not shown) taken together with Sc, Sm and Y (Figs. 11A, B, C) strongly suggest primary magmatic trends and therefore, inconsistent with any loss or extraneous addition of zircon into the mantle source of the Peddavuru basalts. As such, there is no direct explanation for the negative Zr-Hf anomalies observed in these samples, which is also observed in the case of Phanerozoic arc basalts (Fig. 4F). Alternatively, it is attributed to residual zircon that buffers these elements in the subduction derived liquids, which imparts nearly constant Zr/Hf ratio in the basaltic melts (Rubatto and

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Hermann, 2003). Therefore, we believe that the observed negative Zr-Hf anomaly and the low Zr/Sm ratio in the Peddavuru basalts primarily reflects the nature of the mantle source. 5.4.3. TiO2 variation in the Peddavuru basalts

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The difference between the TiO2 concentrations in the low- and high-Ti basalt

populations in the Peddavuru greenstone belt are very subtle but distinct, in the sense that the

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low-Ti population has TiO2 concentrations essentially less than 1 wt. % compared to the

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high-Ti population (Table 1). Further, in comparison to the low-Ti population, the high-Ti population is characterized by relatively high FeO*, Zr, Nb and Y, and low MgO, Ni and Mg# (Figs. 7 and 10). This suggests that the low-Ti melts are primitive compared to the

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slightly evolved nature of the high-Ti basalts. The continuum observed in the major, trace and rare earth element systematics between the low- and high-Ti basalt populations (Figs. 5, 7, 9,

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10 and 11), in combination with identical chondrite normalized rare earth element patterns

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(Figs. 4A, B) strongly suggests their origin from the same mantle source. The geochemical variations therefore, can be ascribed to reflect minor differences in the degree of partial melting of a depleted mantle source in the spinel stability field (Fig. 10). The combined occurrence of low-Ti and high-Ti basalt magmas is rampant in the Phanerozoic continental flood basalt provinces (e.g. Beard et al., 2017; Jourdan et al., 2007). General stratigraphic disposition indicates that low-Ti basalts are overlain by high-Ti basalt

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flows (e.g. Beard et al., 2017; Song et al., 2009). In some cases, although petrogenetically related, there is geographical separation of the two units (e.g. Fodor, 1987). Given the complex nature of folding of the lithounits in the Archean greenstone belts, it may not be feasible to establish the flow boundaries between the low- and high-Ti basalt units. For instance, both low- and high-Ti variants occur all along the width and strike length of the Peddavuru greenstone belt (Table 1). As such, intermingled occurrence of low- and high-Ti basalts within a single greenstone terrane in the Archean is quite rare. Recent reports confirm

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such an occurrence from the Sitagota Formation in the ~2.5 Ga Mahakoshal Supracrustal belt, Bastar craton, Central India (Khanna et al., 2019; Asthana et al., 1996). In rift-related terranes, the low- and high-Ti basalt sequences are often associated with alkaline basalts

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resulting from low degree partial melting of the sub continental upper mantle in an

extensional regime (e.g. Song et al., 2009). In the available literature there is no record of

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alkaline magmatic rocks in the Peddavuru greenstone belt. Alternatively, the low- and high-

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Ti suite of basalts in the Peddavuru belt instead suggests their origin related to subduction zone magmatic processes involving partial melting of different segments of the mantle wedge under the influence of subduction-derived fluids/ melts (e.g. Walker et al., 1990).

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5.4.4. Contrasting geochemical signatures in the felsic volcanics of the Peddavuru belt The dacite and rhyolite in the Peddavuru greenstone terrane are characterized by

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contrasting geochemical attributes and trace element patterns. For instance, compared to the

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rhyolites, the dacites consist of relatively high TiO2, Al2O3, Na2O, Mg# and Zr, and significantly low SiO2, Nb, Y, Yb and ∑ REE contents (Fig. 12; Table 2). Further, the dacites do not display negative Eu anomaly, as noticeable in the rhyolites (Figs. 4G, H). Although the dacites exhibit negative Nb and Ti anomalies similar to the rhyolites (Figs. 4I, J), they are characterized by positive Zr-Hf anomaly (Fig. 4I). Further, the rhyolites are characterized by less fractionated light-REE [La/Sm]N ~3.9 compared to the dacites that exhibit much steeper

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light-REE [La/Sm]N ~6, which implies that the rhyolites did not fractionate from the dacites. Overall, the geochemical attributes of the Peddavuru dacites are comparable to the Cenozoic western Aleutian dacite lavas (Figs. 4I) that were identified as adakitic slab melts (Yogodzinski et al., 2015). On the basis of trace element attributes, Lesher et al. (1986) have broadly recognized three groups of Archean felsic metavolcanic rocks form ore associated and barren felsic volcanic formations of the Superior Province, Canada. The FI-type felsic metavolcanic rocks

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are dacite and rhyodacite that are characterized by low abundances of HFSE: Zr (86-181 ppm) and Y (3-16 ppm), and heavy-REE (Yb = 0.6-2.5 ppm). The Zr/Y ratio spans a broad

range from 9 to 31. They typically exhibit feeble negative to positive Eu anomaly (Eu/Eu* =

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0.87 – 2.0) along with steep chondrite normalized REE patterns ([La/Yb]N = 6 – 34). In

contrast, the FII (rhyodacite and rhyolite) and FIII (rhyolite and high Si-rhyolite) types are

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collectively characterized by higher Zr (200-670 ppm), Y (29-213 ppm) with low Zr/Y (2.1 –

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10), and gently sloping to near flat REE patterns ([La/Yb]N = 1 – 10). The HFSE and REE systematics of the Peddavuru dacites and rhyolites are comparable to the FI-type dacites and rhyodacites, respectively, of Lesher et al. (1986). The Peddavuru rhyolites display

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fractionated REE patterns (Fig. 4H; [LaN/YbN = 7.5 – 11.8]) with moderate negative Eu anomaly (Eu/Eu* ~ 0.62). The negative Eu anomaly is consistent with fractional

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crystallization of plagioclase. By comparison, the Peddavuru dacites exhibit intense

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fractionated REE (Fig. 4G; [LaN/YbN = 19 – 33]) and negligible Eu anomaly (Eu/Eu* ~ 0.97), which is inconsistent with any significant plagioclase fractionation. Collectively, the REE patterns imply that melting took place at depth with garnet in the residue. The difference in the La/Yb ratio, however, suggests that the rhyolites were produced from relatively shallow depths compared to the dacites, and by analogy resemble lower endmember of the FI-type felsic metavolcanic rocks (Fig. 13A; Lesher et al., 1986). Unlike the FII or FIII-type

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felsic metavolcanic rocks, which are produced from high degree (30% - 60 %) partial melting and/or fractional crystallization from silicic and/or intermediate crustal sources, the FI-type are necessarily produced from relatively low degree partial melting (10% - 20 %) of basaltic sources at comparatively high-pressures and depth (Lesher et al., 1986). Moreover, the rhyolites produced from extreme fractionation of basaltic melts generated in intraoceanic back-arc settings are tholeiitic in nature, with near flat REE patterns (Kerrich et al., 2008). On the contrary, the Peddavuru rhyolites are typically calc-alkaline in nature (Fig. 6B).

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Therefore, we presume that the Peddavuru rhyolites were produced from low degree partial melting combined with minor plagioclase fractionation in the sub-arc mantle, rather extreme fractional crystallization from a basaltic melt in the shallow upper mantle region.

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5.4.5. The slab-melt component

Adakites, by definition (Defant and Drummond, 1990), typically have ≥ 56 wt. % SiO2, ≥

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15 wt. % Al2O3, MgO usually < 3 wt. %, Nb ≤ 8 ppm, Y ≤ 18 ppm, and Yb ≤ 1.9 ppm. On

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the basis of SiO2 – MgO criterion, Martin et al. (2005) broadly classified adakites into two types: low-silica adakite and high-silica adakite. The low silica – high Mg# (~ 60) type adakites are presumably generated by partial melting of a slab-melt hybridized mantle wedge

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under high pressure conditions (> 2.5 GPa) with garnet in the residue (Rapp et al., 1999; Moyen, 2009). In contrast, the high silica – low Mg# (< 50) type adakites with low Cr, and

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Ni contents are thought to represent the ‘slab-melts’ that had minimal interaction with the

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peridotitic mantle wedge prior to their eruption (Gustcher et al., 2000). In the (Yb)N vs (La/Yb)N bivariate discrimination diagram (Fig. 13B), in contrast to the

rhyolites, the Peddavuru dacites with low Yb ≤ 0.6 ppm and relatively high La/Yb = 27 – 66 plot in the Phanerozoic adakite / Archean TTG field. Further, the geochemical characteristics are comparable to the Cenozoic high-Si adakites (Fig. 13A; HSA; Martin et al., 2005). The sub-chondritic Nb/Ta (~11) and super- chondritic Zr/Sm (55 – 91) ratios in the Peddavuru

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dacites (Fig. 13C) is consistent with partial melting of a low-Mg amphibolite source in a subduction-related setting (Drummond et al., 1996; Foley et al., 2002). In addition, the Peddavuru dacites are characterized by low Y (~6 ppm) and Yb (~0.47 ppm) contents coupled with strongly fractionated REE resulting in high La/Yb (≥ 27) and Gd/Yb (> 2) ratios, indicative of melt generation from a source with garnet in the residue. Unlike the primitive adakitic slab melts that have high Mg# (≥ 60; Yogodzinski et al., 2015), the Peddavuru dacites consist of Mg# 30-48, which is consistent with relatively evolved nature

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of the rocks, and similar to that recognized in the high-silica adakites (Martin et al., 2005). The low Mg# further suggests that these slab melts presumably had minimal interaction with the peridotitic mantle wedge prior to their eruption and emplacement at shallow levels in the

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crust (Gustcher et al., 2000). Accordingly, the Peddavuru dacites are interpreted as adakitic slab-melts that were generated by the partial melting of a low-Mg amphibolite source at

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deeper levels with garnet in the residual phase, in a subduction-related environment. The arc-

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like geochemical attributes of the Peddavuru felsic volcanics suggest coeval eruption of these two magmas involving slab-melting to produce adakites, and melting of the base of the arc crust in an extensional regime to generate the rhyolites (e.g. Manikyamba et al., 2007).

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5.5. Magmatism in a Phanerozoic-type back-arc setting The trace and rare earth element systematics of the basalts and felsic volcanics in the

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Peddavuru belt provide compelling evidence for their eruption in an intraoceanic arc setting

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(see Figs. 4, 8, 9). Further, the compositional range in the basalts and the conditions of melt generation is identical to those produced in the modern-day back-arc systems (Figs. 7 and 10; e.g. Mariana back-arc; Pearce et al., 2005). Woodhead et al. (1993) and Stern et al. (2003) concluded that the mantle sources of the basalts generated in the back-arc regions are relatively more fertile and enriched in HFSE (Zr, Nb) compared to the source regions of the arc basalts. As noted by Pearce and Stern (2006), the basalts generated in the back-arc basins

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are typically characterized by geochemical signatures intermediate to those of arc and MORB, which are primarily governed by dynamic factors such as: (1) nature of the mantle inflow at the site of melt generation in the back-arc regions, and (2) the proximity of the site of melt generation to the active volcanic arc front. Nevertheless, the second factor presumably plays a major role in modifying the chemistry of the back-arc magmas by overprinting them with a subduction zone component. Otherwise, the back-arc magmas that are generated distal to the volcanic arc are virtually indistinguishable from those produced at

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mid-oceanic ridges. As a corollary, the Peddavuru basalts are characterized by relatively higher Nb contents and Nb/Th ratio, and lower La/Nb (Fig. 14A, B), compared to the arc lavas, reflecting MORB-type geochemical attributes, combined with negative Nb and Ti

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anomalies relative to Th and REE, a signature typically of magmas that are erupted proximal to an arc source (Fig. 4C, D). Accordingly, they plot in-between arc and MORB (Fig. 14B,

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C).

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Pearce (2008) have shown that Nb/Yb can be used as a mantle flow tracer and Ba/Nb, Ba/Th, Th/Nb and Th/Yb as tracers to assess the magnitude of subduction input in the backarc regions. In the Nb/Yb vs. Th/Yb diagram, the Peddavuru basalts plot sub-parallel to the

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terrestrial MORB-mantle array, and in the Phanerozoic back-arc field (Fig. 15B). Therefore, we propose that the basalts in the Peddavuru greenstone belt were generated in a Neoarchean

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back-arc setting.

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5.6. A brief review of the nature of magmatism in the eastern Dharwar craton (EDC) Besides Peddavuru greenstone belt, the eastern Dharwar carton (EDC) hosts seven major

greenstone belts [Fig. 1B; Gadwal, Veligallu, Kadiri, Hutti, Kushtagi, Penakacherla, and Sandur] of Neoarchean age (Jayananda et al., 2013; Khanna et al., 2014, 2016) that consist of well-preserved metavolcanic rock sequences comprising basalt, andesite, rhyolite, boninite and adakite. Basalt is the predominant rock type in these greenstone belts. In brief, the

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Gadwal belt has a N-S disposition in the southern part and a NNW-SSE trend in the north. It has an approximate strike length of ~90 km with a maximum width of ~5 km in the central part. Basalt is the predominant rock type with subordinate units of andesite, rhyolite, adakite and boninite (Manikyamba and Khanna, 2007). The Veligallu belt broadly exhibits N-S trend with an approximate strike length of 60 km and a maximum width of ~ 6 km in the central part. The belt consists of basalt – high-Mg andesite – adakite suite of rocks (Khanna et al., 2015) with subordinate amounts of ultramafic arc-cumulates (Khanna et al., 2016). The

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Kadiri belt is ~75 km long and ~2.5 km wide. It consists of voluminous tracts of felsic volcanic rocks of rhyolitic composition with subordinate units of basalt and andesite

(Manikyamba et al., 2015). The Hutti belt predominantly consists of basalt with minor units

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of adakite and high-Mg andesite (Manikyamba et al., 2009). Kushtagi in the north, and Penakacherla in the south, are part of a ~400 km long linear composite greenstone belt

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Hungund-Kushtagi-Penakacherla-Ramagiri. The Kushtagi belt consists of diverse suite of

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rocks comprising high-Mg and high-Fe basalt, high-Mg dacite and andesite, with adakite (Naqvi et al., 2006). The Penakacherla belt essentially consists of pillowed and massive basalt horizons (Manikyamba et al., 2004). The Sandur belt is located within the Closepet

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granite (Fig. 1B). It consists of tectonically accreted terranes made up of plume and arc magmatic rocks. The plume generated lithologies include komatiite-tholeiite suite in the

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central and western parts, whereas, basalt-adakite association represents the arc-related

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volcanic sequence in the eastern part of the belt (Manikyamba et al., 2008). The basalts in these greenstone belts are primitive intraoceanic arc-tholeiites that exhibit trace and rare earth element attributes identical to those generated in the Phanerozoic back-arc basins (e.g. Manikyamba et al., 2009, 2015; Khanna, 2013; Khanna et al., 2015). A review of the recent literature (Table 4) suggests that a significant proportion of the accreted arc crust in the eastern Dharwar craton evolved in a Phanerozoic-type back-arc setting. On this basis, we

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propose that magmatism in a Neoarchean back-arc basin significantly contributed to the 2.7 Ga peak of crustal growth activity and continental crust formation events in the eastern Dharwar craton, India, and elsewhere on the Earth. 7. Conclusions The Peddavuru greenstone belt is one among the comparatively least studied greenstone belts in the eastern Dharwar craton, India. It hosts mafic and felsic volcanic rocks, which is consistent with bimodal nature of magmatism. The rocks exhibit regional foliation and the

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entire package has been metamorphosed under lower amphibolitefacies conditions. On the basis of TiO2 concentration and HFSE systematics, the basalts can be broadly distinguished into low- and high-Ti subgroups. The variation in the Ti concentrations and HFSE

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abundances can be ascribed to variable degree of partial melting of a depleted MORB mantle source in the spinel stability field. MORB-type trace element attributes and arc-like

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geochemical patterns is consistent with the generation of these basalts in an intraoceanic

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back-arc setting. The contrasting geochemical signatures in the felsic volcanic rocks suggest independent evolution of the two magma series. Na-rich dacites as the product of adakitic slab-melts, and rhyolites as the fractionated products of the melts generated beneath the arc

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crust under extension. The volcanic sequences from the eight greenstone belts [Peddavuru, Gadwal, Veligallu, Kadiri, Hutti, Kushtagi, Penakacherla, and Sandur], in the eastern

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Dharwar craton are characterized by basalt-adakite association, wherein the basalts exhibit

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typical back-arc signatures. We believe that magmatism in a Neoarchean back-arc basin significantly contributed to the ~ 2.7 Ga peak of crustal growth activity and continental crust formation in the eastern Dharwar craton, India, and elsewhere on the Earth.

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Acknowledgements TCK is thankful to Dr. V. M. Tiwari, Director NGRI for permission [NGRI/Lib /2019/Pub-58] to publish this work. The work was funded from the CSIR-NGRI in-house project MLP-6406-28 (CM). We thankfully acknowledge Dr. C. Manikyamba for extending the XRF and HR-ICP-MS analytical facilities. Mr. L. Srikanth is thankfully acknowledge for his assistance in the field. We profusely thank Astrid Holzheid and Dewashish Upadhyay for the editorial handling of our manuscript. We appreciate the critical, but constructive reviews

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by the two anonymous reviewers, which significantly improved the scientific quality of the

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Figure captions

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Fig. 1 (A) inset sketch of southern part of peninsular India depicting the Dharwar craton, (B)

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Generalized geological map of peninsular India, showing the study area and the disposition of the eight major greenstone belts in the eastern Dharwar craton that are separated by Chitradurga boundary fault, from the greenstone belts in the western sector of the Dharwar

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Krishnappa (1991).

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craton, (C) generalized geological map of the Peddavuru greenstone belt, after Srinivasan and

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Fig. 2 Field photograph showing (A) basalt and (B) felsic volcanic rocks in the Peddavuru

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greenstone belt.

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re

-p

ro of

44

Fig. 3 Photomicrographs showing (A) planar fabric in the basalt comprising of green

ur

amphibole and plagioclase, (B) euhedral rutile and (C) magnetite, as accessory mineral phases in the basalt; Phenocryst of (D) quartz, (E) Plagioclase, and (F) K-feldspar in the

Jo

felsic volcanic rocks, and (G, H) subordinate amounts of biotite, and accessory euhedral grains of apatite in the felsic groundmass.

lP

re

-p

ro of

45

Fig. 4 (A, B) Chondrite normalized rare earth element (REE) and (C, D) primitive mantle

na

normalized trace element variation patterns of Peddavuru basalts. (E, F) REE and trace element patterns of Phanerozoic Mariana arc (Elliott et al., 1997) and back-arc (Pearce et al., 2005), along with N-MORB (Hofmann, 1988) and ocean plateau basalt (OPB) from Ontong

ur

Java Plateau (Fitton and Godard, 2004), are shown for comparison. (G, H) Chondrite and (I,

Jo

J) primitive mantle normalized patterns for felsic volcanic rocks of Peddavuru greenstone belt. The geochemical composition of Western Aleutian dacite (Yogodzinski et al., 2015) is shown for comparison. The normalizing values for chondrite and primitive mantle are from Sun and McDonough (1989). See text for details.

na

lP

re

-p

ro of

46

Fig. 5 Bivariate major element oxide (A, B, C, D), and trace and rare earth element (E, F, G,

ur

H) diagrams for the Peddavuru mafic and felsic volcanic rocks. The AFC model assumes 100% melt fraction remaining, with an r factor of 0.3, and decreases to 37% in steps of 7%.

Jo

The AFC model is calculated from Ersoy and Helvacı (2010). See text for details.

na

lP

re

-p

ro of

47

Fig. 6 (A) Nb/Y versus Zr/Ti discrimination diagram plotted for the Peddavuru mafic and felsic volcanic rocks, after Winchester and Floyd (1977). (B) AFM diagram (Irvine and

ur

Baragar, 1971) for the Peddavuru volcanics. Basalts exhibit tholeiitic trends, whereas the

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felsic volcanics are calc-alkaline in nature.

na

lP

re

-p

ro of

48

Fig. 7 Bivariate plots of TiO2 vs. (A) FeO*, (B) MgO, (C) Cr vs. Ni; TiO2 vs. (D)

ur

Al2O3/TiO2, (E) CaO/TiO2, and (F) Ti/Sc vs. Ti/V, for the Peddavuru low-Ti and high-Ti basalts. The data points for Mariana arc (Elliott et al., 1997), fore-arc (Reagen et al., 2010)

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and back-arc (Pearce et al., 2005) are also shown for comparison. See text for details.

lP

re

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49

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Fig. 8 bivariate diagram of (A) Ti vs. Zr, after Hatton and Sharpe (1989); MgO vs. (B) (La/Sm)N, and (C) Nb/Th, and (D) Th vs. Th/Ce, plotted for the Peddavuru basalts. Values

ur

for primitive mantle (PM), ocean island basalt (OIB) and normal mid ocean ridge basalt (NMORB) are from Sun and McDonough (1989). Archean upper continental crust (AUCC)

Jo

values are from Rudnick and Gao (2004). The data for Phanerozoic MORBs is from Gale et al. (2013). The Peddavuru basalts are inconsistent with crustal contamination. See text for details.

lP

re

-p

ro of

50

Fig. 9 (A) Nb/Y versus Ti/Y immobile element discrimination diagram after Pearce (1982), in which the Peddavuru basalts distinctly plot in the volcanic arc field. (B) Yb vs. Ce

na

bivariate diagram, after Hawkesworth et al. (1993), for Peddavuru basalts, which plot in the

Jo

ur

Phanerozoic intraoceanic arc fields. See text for details.

lP

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51

Fig. 10 Y versus high field strength elements (A) Ti, (B) Zr, (C) Nb and REE (D) Ce diagram

na

showing variable degrees of partial melting of a depleted MORB mantle source in the spinel stability field can produce the elemental concentrations observed in the Peddavuru basalts.

ur

The source mineralogy: Ol = 0.578, Opx = 0.27, Cpx = 0.119, Sp = 0.033; melt proportions: Ol = 0.1, Opx = 0.2, Cpx = 0.68, Sp = 0.02; partition coefficient data, and the DMM values

Jo

are from McKenzie and O’Nions (1991, 1995). Mariana back-arc basin basalts (Pearce et al., 2005) are also shown for comparison. See text for details.

lP

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52

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Fig. 11 Zr vs. (A) Hf, (B) Zr/Sc, (C) Zr/Sm, and (D) Zr/Y bivariate diagram for Peddavuru

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basalts. See text for details.

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Fig. 12 SiO2 vs. major element oxide (A, B, C) and trace elements (D, E, F) bivariate

Jo

ur

diagram for Peddavuru felsic volcanics. See text for details.

ur

na

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54

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Fig. 13 (A) (Yb)N vs. (La/Yb)N bivariate diagram plotted for Peddavuru felsic volcanic rocks, also shown for comparison are the felsic metavolcanic rocks from the Superior Province, Canada, after Lesher et al. (1986). (B) (Yb)N vs. (La/Yb)N discrimination diagram after Martin (1986). (C) Zr/Sm vs. Nb/Ta discrimination diagram, after Foley et al. (2002). In contrast to the rhyolites, the dacites plot in the Phanerozoic adakite / Archean TTG field. Representative average low and high silica adakite is from Martin et al. (2005). Western

55

Aleutian dacites interpreted as adakitic slab-melts (Yogodzinski et al., 2015) are also shown

Jo

ur

na

lP

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ro of

for comparison. See text for details.

Fig. 14 Nb vs. (A) (La/Nb)pm and (B) Nb/Th, and (C) (La/Sm)N vs. (Nb/La)pm plots for Peddavuru basalts. Mariana arc (Elliott et al., 1997), back-arc (Pearce et al., 2005), and MOR

56

basalts (Gale et al., 2013) are shown for comparison. The values for N-MORB and OIB are

lP

re

-p

ro of

from Sun and McDonough (1989). See text for details.

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Fig. 15 Tectonic discrimination diagram of Nb/Yb vs Th/Yb after Pearce (2008). The dashed field boundaries for TH = tholeiitic, CA = calc-alkaline, and SHO = shoshonitic rocks are

ur

from convergent margins. The bold arrows in the bottom right are S = subduction component, C = crustal contaminant component, W = within plate, and f = fractional

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crystallization vectors. The basalts display an oblique trend sub-paralleling the terrestrial MORB mantle array and plot in the Phanerozoic back-arc fields. The Phanerozoic arc, fore-arc, and back-arc basalt fields are from Metcalf and Shervais (2008). The AFC model calculated from Ersoy and Helvacı (2010), for the Mesoarchean TTG from the Dharwar craton (Naqvi et al., 2009) and the most primitive Peddavuru basalt sample EPB-26, is shown to rule out any crustal contamination. See text for details.

57

f

Table 1 Major element oxide (in wt. %), trace element (in ppm) and rare earth element (in ppm) concentrations of Peddavuru basalts, eastern Dharwar craton, India.

EP B43 EP B69 EP B72 EP B88 EP B89 EP B90

2

3

3

1 3. 5 9 1 4. 4 0 1 2. 1 4 1 4. 6 3 1 3. 8 0 1 3. 9 8 1 2. 3 2 1 3. 4 4 1 3. 3 4

1 4. 3 2 1 2. 8 0 1 2. 3 2 1 4. 4 0 1 3. 9 3 1 3. 6 3 1 2. 7 3 1 3. 4 8 1 3. 3 1

4 6. 6 5 4 7. 4 9 4 9. 7 3 4 6. 5 3 4 8. 0 5 4 8. 1 9 5 0. 0 4 4 8. 0 4 4 8. 2 7

0. 9 1 0. 8 7 0. 8 5 0. 9 2 0. 9 6

0. 1 5 0. 1 7

M g O 1 0. 3 1

0. 2 0

9. 9 1 1 0. 3 1

0. 2 0

8. 3 9

0. 1 5

8. 7 1

C a O 1 1. 6 3 1 2. 3 8 1 2. 8 2 1 3. 4 9 1 1. 8 0 1 2. 1 2 1 1. 3 0 1 2. 8 6 1 3. 4 1

N a2 O 1. 6 6 1. 7 5 1. 4 0 1. 1 3

K

2

2

O

O 0 . 7 1 0 . 1 5 0 . 1 3 0 . 1 9 0 . 5 0 0 . 3 2 0 . 4 3 0 . 2 8 0 . 2 3

5

M g #

C r

C o

N i

R b

S r

0. 0 7

5 9

2 1 1

5 1

1 1 7

2 1

1 6 8

0. 0 7

6 1

2 0 2

4 9

1 1 4

0. 1 0

6 2

2 4 3

5 1

1 2 9

0. 1 1

5 4

1 8 7

6 0

1 2 8

5

2 0 2

2. 0 2

0. 0 8

5 5

3 0 4

4 8

1 4 1

1 1

1 6 0

0. 9 7 0. 7 4 0. 9 2 0. 9 6

0. 1 4 0. 1 8

8. 6 4 1 0. 2 6

0. 2 1

9. 1 8

0. 2 1

8. 7 1

1. 9 4

0. 0 8

5 6

2 7 1

4 8

1 2 9

7

1 3 6

1. 8 9

0. 1 0

6 2

2 3 4

5 2

1 7 3

1 9

1 7 8

1. 4 9

0. 1 1

5 7

2 2 3

5 4

1 2 9

9

1 3 7

1. 4 3

0. 1 1

5 7

2 4 3

5 4

1 2 3

6

1 6 1

C s 0 . 4 0 0 . 1 3 0 . 1 8 0 . 2 2 0 . 3 8 0 . 2 2 0 . 2 8 0 . 3 2 0 . 4 8

B a 1 2 5

pr

2

P M n O

S c

V

4 0

2 7 4

4 2

3 8

2 6 0

4 4

4 0

2 6 8

5 9

4 7

3 1 7

1 2 1

3 9

2 7 2

8 3

4 0

2 7 4

1 4 0

3 8

2 6 4

8 5

3 9

2 8 0

6 3

4 5

3 0 1

T a 0 . 1 4 0 . 1 3 0 . 1 6 0 . 1 7 0 . 1 7 0 . 1 8 0 . 1 8 0 . 2 1 0 . 2 1

e-

F e2 O

2

1 1 1

4

1 2 1

Pr

EP B41

A l2 O

na l

EP B26

T i O

Jo ur

EP B23

Si O

oo

lo wTi ba sal ts

N b 1 . 9 6 1 . 8 6 2 . 1 9 2 . 5 9 2 . 8 2 2 . 7 8 2 . 3 7 2 . 8 2 2 . 9 5

Z r

4 5

4 9

5 5

5 9

4 8

4 2

5 7

5 5

6 4

H f 1 . 2 3 1 . 3 4 1 . 4 8 1 . 6 0 1 . 3 3 1 . 1 7 1 . 5 4 1 . 5 5 1 . 7 9

T h 0 . 4 8 0 . 4 2 0 . 4 5 0 . 5 4 0 . 4 5 0 . 3 1 0 . 4 7 0 . 4 9 0 . 4 6

U 0 . 2 6 0 . 1 9 0 . 3 9 0 . 2 3 0 . 2 1 0 . 1 4 0 . 3 4 0 . 2 4 0 . 1 9

Y

1 8

1 7

1 9

2 3

2 0

2 0

2 0

2 3

2 4

L a 3 . 3 8 3 . 0 3 3 . 4 3 4 . 0 2 3 . 6 2 3 . 3 1 3 . 4 4 3 . 9 0 4 . 1 6

C e 8. 5 1 7. 4 4 8. 7 5 1 0. 4 8 9. 3 8 8. 8 7 9. 3 0 1 0. 6 1 1 1. 1 0

P r 1 . 2 3 1 . 1 0 1 . 2 9 1 . 5 7 1 . 4 0 1 . 3 8 1 . 4 4 1 . 6 5 1 . 7 0

N d 6. 2 0 5. 6 2 6. 1 8 7. 5 2 6. 7 1 6. 4 8 7. 0 0 7. 9 4 8. 2 3

S m 1 . 9 3 1 . 8 1 2 . 0 7 2 . 4 7 2 . 1 1 2 . 0 9 2 . 3 0 2 . 6 4 2 . 6 6

E u 0 . 7 4 0 . 6 5 0 . 7 8 0 . 8 9 0 . 7 2 0 . 7 5 0 . 8 2 1 . 0 2 0 . 9 7

G d 2 . 6 0 2 . 3 7 2 . 8 4 3 . 3 4 2 . 7 7 2 . 7 2 3 . 1 0 3 . 6 1 3 . 5 4

T b 0 . 4 7 0 . 4 4 0 . 4 9 0 . 5 9 0 . 4 8 0 . 4 8 0 . 5 4 0 . 6 4 0 . 6 2

D y 3 . 0 8 2 . 9 0 3 . 1 0 3 . 7 3 3 . 1 7 3 . 1 4 3 . 2 3 3 . 8 5 3 . 8 4

H o 0 . 6 6 0 . 6 2 0 . 6 9 0 . 8 3 0 . 6 7 0 . 6 5 0 . 7 2 0 . 8 5 0 . 8 5

E r 1 . 9 3 1 . 8 1 1 . 9 2 2 . 3 8 1 . 9 6 1 . 9 2 2 . 0 7 2 . 4 3 2 . 3 9

T m 0 . 2 8 0 . 2 5 0 . 2 8 0 . 3 5 0 . 2 9 0 . 3 0 0 . 3 2 0 . 3 7 0 . 3 5

Y b 1 . 8 0 1 . 7 2 1 . 8 0 2 . 3 2 2 . 0 0 2 . 0 1 2 . 2 4 2 . 5 5 2 . 3 0

L u 0 . 2 7 0 . 2 6 0 . 2 6 0 . 3 4 0 . 3 4 0 . 3 1 0 . 3 4 0 . 3 8 0 . 3 3

58

high-Ti basalts 4 EP 9. B4 1/J 9 4 EP 6. B8 8 6

0. 6 1 0. 9 2 0. 9 4 0. 7 1 0. 8 9

0. 1 6

8. 8 6

0. 1 4 0. 2 0

8. 8 9 1 1. 0 9

0. 1 5

9. 1 8

0. 1 9

9. 9 0

0. 2 0

7. 9 7

0. 2 1

9. 6 3

1 2. 4 1 1 1. 6 5 1 1. 4 7 1 1. 2 5 1 0. 2 7 1 1. 7 1 1 0. 3 8 1 2. 6 2

1. 9 4 2. 0 1 2. 4 1 2. 0 6 2. 4 2 1. 5 9 2. 8 1

0 . 4 0 0 . 3 1 0 . 2 4 0 . 9 3 0 . 3 2 0 . 3 4 0 . 3 2 0 . 3 6 1 . 0 4

0. 1 0

5 5

2 3 0

5 2

1 2 7

2 2

3 1 9

0. 0 8

5 5

2 0 6

4 9

1 2 3

1 0

1 1 5

0. 0 8

5 8

2 7 2

4 8

1 2 7

7

1 5 2

0. 1 3

6 6

3 0 0

4 8

1 4 1

7 0

2 0 6

0. 1 3

6 0

3 2 1

5 4

1 4 9

1 3

0. 1 2

6 0

2 4 4

5 2

1 2 3

1 7

0. 1 0

5 6

3 0 3

4 2

1 3 4

8

1 5 4

1. 4 7

0. 1 0

5 9

2 2 6

5 0

1 1 5

1 0

2 1 1

0. 7 2

1. 3 7 1. 1 7

0. 2 0

7. 2 5

9. 9 4

1. 4 7

4 5

2 0 4

6 0

1 0 9

4 2

1 4 4

0. 1 9

6. 9 2

2. 0 9

0. 1 5

8. 7 0

9. 9 6 1 2. 0 3

2. 1 0

0 . 3 5 0 . 3 5

7

1 7 8

8

1 4 5

0. 1 2

0 . 5 9 0 . 2 9 0 . 2 1 0 . 4 9 0 . 2 5 1 . 0 5 0 . 1 7 0 . 2 3 0 . 3 3

1 3 4

4 3

3 0 4

7 0

4 3

2 7 6

6 8

0. 1 4

4 6

9 1

5 7

8 9

0. 1 1

5 2

1 9 7

5 1

1 0 0

0 . 1 9 0 . 1 8 0 . 1 9 0 . 1 9 0 . 1 9 0 . 2 1 0 . 2 2 0 . 1 9 0 . 2 1

1 4 7 1 5 1

0 . 0 8 0 . 0 8

2 . 7 6 2 . 8 2 2 . 7 3 2 . 8 0 2 . 9 9 2 . 9 2 2 . 9 9 2 . 7 0 3 . 4 4

4 1

1 . 1 4 1 . 6 3 1 . 3 7 1 . 5 4 1 . 4 5 1 . 8 0 1 . 7 1 1 . 7 0 1 . 0 9

0 . 6 4 0 . 3 8 0 . 4 0 0 . 4 8 0 . 4 8 0 . 4 7 0 . 4 6 0 . 4 3 0 . 5 1

0 . 4 0 0 . 1 3 0 . 1 7 0 . 2 6 0 . 1 9 0 . 2 3 0 . 1 7 0 . 2 0 0 . 1 8

5 9

4 0

2 7 4

8 8

3 8

2 6 2

1 0 9

4 2

2 9 5

8 9

4 4

2 9 8

1 5 1

4 1

2 8 5

7 3

4 2

2 8 4

1 7 0

4 6

4 0 1

5 6

4 0

3 5 3

4 3

3 7

2 8 9

0 . 2 8 0 . 2 0

4 . 2 7 2 . 8 9

4 9

5 6

5 4

6 5

6 2

6 1

3 9

1 0 0

2 . 7 3 1 . 8 1

0 . 8 6 0 . 8 9

0 . 4 6 0 . 2 8

6 5

4 . 6 8 3 . 2 2 3 . 5 4 4 . 2 8 3 . 7 8 3 . 8 5 3 . 8 3 3 . 7 4 3 . 9 8

1 2. 1 1

9. 9 5 1 1. 2 5

1 . 8 0 1 . 4 1 1 . 3 9 1 . 6 7 1 . 6 7 1 . 6 8 1 . 5 6 1 . 5 2 1 . 8 1

7 . 8 7 4 . 5 1

1 6. 9 2 1 1. 0 7

2 . 4 5 1 . 6 3

f

1 6. 3 1 1 5. 6 3

8. 4 0

2 4

oo

1 3. 2 0 1 2. 8 9

0. 2 2

pr

0. 9 6

1 3. 3 9 1 4. 2 5 1 2. 6 5 1 1. 3 4 1 1. 9 4 1 3. 2 1 1 2. 6 0 1 3. 2 7 1 7. 2 6

e-

0. 9 9

1 2. 2 8 1 3. 7 4 1 4. 3 9 1 1. 3 0 1 1. 9 5 1 2. 5 6 1 2. 3 7 1 2. 3 1 1 3. 3 7

Pr

0. 7 7

na l

EP B93 EP B10 4 EP B11 7 EP B12 0 EP B12 4 EP B12 6 EP B12 9 EP B15 5

5 0. 0 9 4 7. 9 6 4 8. 7 7 5 1. 0 9 5 2. 7 3 4 9. 4 4 5 2. 5 3 4 9. 1 5 4 8. 6 5

Jo ur

EP B91

2 2

1 9

2 0

2 2

2 5

2 1

2 2

2 9

3 2

2 6

8. 8 8 9. 0 9 1 1. 1 4 1 0. 5 0 1 0. 6 5 1 0. 2 1

8. 5 9 6. 9 9 6. 5 2 7. 9 4 8. 0 6 8. 1 6 7. 4 6 7. 4 3 9. 3 3

1 1. 5 0 8. 2 4

2 . 7 2 2 . 2 3 2 . 0 5 2 . 5 8 2 . 6 3 2 . 7 0 2 . 4 0 2 . 4 4 3 . 0 6

0 . 9 7 0 . 6 5 0 . 7 5 0 . 9 5 0 . 9 2 0 . 9 8 0 . 8 7 0 . 9 8 1 . 1 8

3 . 5 5 2 . 9 8 2 . 6 9 3 . 4 5 3 . 5 4 3 . 6 8 3 . 1 9 3 . 3 0 4 . 1 3

0 . 6 1 0 . 5 3 0 . 4 6 0 . 5 6 0 . 6 3 0 . 6 3 0 . 5 3 0 . 5 8 0 . 7 3

3 . 8 4 3 . 4 1 3 . 0 1 3 . 4 0 3 . 7 7 3 . 9 7 3 . 4 7 3 . 5 9 4 . 8 1

0 . 8 6 0 . 7 4 0 . 6 6 0 . 7 7 0 . 8 3 0 . 9 0 0 . 7 6 0 . 7 9 1 . 0 4

2 . 3 3 2 . 1 0 1 . 8 2 2 . 1 0 2 . 3 5 2 . 4 9 1 . 9 9 2 . 2 1 2 . 8 3

0 . 3 4 0 . 3 2 0 . 2 6 0 . 3 0 0 . 3 5 0 . 3 6 0 . 2 9 0 . 3 2 0 . 4 1

2 . 1 9 2 . 1 2 1 . 8 5 2 . 1 3 2 . 5 1 2 . 4 8 1 . 9 1 2 . 0 6 2 . 6 5

0 . 3 2 0 . 3 5 0 . 2 9 0 . 3 2 0 . 3 9 0 . 3 7 0 . 2 8 0 . 3 0 0 . 3 9

3 . 4 1 2 . 6 5

1 . 1 7 0 . 8 9

4 . 5 1 3 . 5 1

0 . 8 0 0 . 6 5

5 . 3 4 4 . 3 1

1 . 1 4 0 . 9 3

3 . 3 8 2 . 7 5

0 . 4 9 0 . 3 9

3 . 2 0 2 . 5 8

0 . 4 9 0 . 3 9

59

EP B78 EP B79 EP B80 EP B81 EP B82 EP B83 EP B84 EP B85

1. 3 0 1. 1 9 1. 0 7 1. 1 0 1. 2 0

0. 1 9

8. 3 2

0. 1 5

8. 3 6

0. 1 7

6. 7 7

0. 1 3

7. 1 5

0. 1 9

7. 6 4

0. 1 6

7. 8 8

0. 1 6

7. 3 6

1 0. 1 9 1 1. 1 3 1 3. 5 6 1 0. 3 3 1 1. 9 1 1 1. 5 3 1 2. 9 3 1 1. 8 5 1 2. 4 8 1 3. 2 4 1 2. 1 6 1 2. 7 3

2. 5 8 1. 5 6 1. 5 1 3. 0 9 2. 5 0 2. 5 3 1. 6 4

0 . 4 9 0 . 4 8 0 . 1 9 0 . 3 4 0 . 4 5 0 . 7 0 0 . 5 8 0 . 9 6 0 . 4 1 0 . 5 0 0 . 5 9 0 . 4 9

0. 0 9

5 2

1 7 2

1 2

1 1 8

5 0

8 9

0. 1 0

5 0

9 2

5 1

7 5

7

1 1 0

0. 0 9

5 2

2 0 2

5 2

1 0 6

2

1 2 9

0. 1 1

4 6

9 1

4 8

7 1

5

1 5 3

0. 0 9

5 4

2 3 1

5 9

1 1 5

1 8

0. 0 9

5 2

1 9 8

4 9

9 9

2 4

0. 0 9

5 3

2 1 0

5 0

1 0 2

2 3

1 1 0

1. 8 6

0. 1 0

5 2

2 3 9

5 6

1 1 3

4 6

1 6 1

1. 1 2 1. 0 9 1. 3 8 1. 1 1

0. 1 6

7. 9 1

0. 1 6

7. 9 1

0. 1 5

7. 1 8

0. 1 6

7. 8 7

2. 1 0

0. 0 9

5 5

2 1 5

5 3

1 0 8

9

1 4 2

1. 5 4

0. 0 9

5 4

2 1 1

5 4

1 0 9

1 7

1 1 4

2. 0 9

0. 1 0

5 1

2 7 1

6 0

1 2 4

2 4

1 4 9

1. 8 6

0. 0 9

5 4

2 0 3

4 9

1 0 0

2 1

1 1 7

0 . 1 4 0 . 1 3 0 . 0 5 0 . 1 0 0 . 5 2 0 . 5 2 0 . 6 9 1 . 9 5 0 . 2 7 0 . 5 4 0 . 6 9 0 . 6 2

6 1

3 9

2 7 4

6 5

4 1

3 1 9

5 2

0 . 1 6 0 . 2 6 0 . 2 1 0 . 2 5 0 . 1 7 0 . 1 2 0 . 1 5 0 . 1 7 0 . 1 5 0 . 1 6 0 . 1 8 0 . 1 5

1 5 7 1 4 1

2 . 3 1 4 . 0 8 3 . 0 2 3 . 9 5 2 . 4 8 1 . 8 6 2 . 2 4 2 . 5 2 2 . 2 7 2 . 2 7 2 . 8 2 2 . 2 1

5 2

1 . 4 3 2 . 1 8 1 . 6 8 2 . 1 2 1 . 2 0 1 . 2 5 1 . 3 5 1 . 1 2 1 . 4 3 1 . 4 7 1 . 7 6 1 . 1 4

4 0

3 0 6

5 0

3 9

3 0 5

1 0 4

4 7

3 1 7

1 0 3

4 1

2 6 8

9 1

4 3

2 9 0

3 0 6

4 7

3 2 4

9 5

4 5

2 9 0

8 5

4 4

2 8 7

1 3 2

5 5

3 6 4

9 0

4 2

2 8 2

0 . 6 1 1 . 0 0 0 . 6 6 1 . 0 3 0 . 4 0 0 . 3 1 0 . 3 4 0 . 3 8 0 . 4 6 0 . 3 8 0 . 4 2 0 . 3 2

0 . 2 4 0 . 3 0 0 . 2 4 0 . 2 8 0 . 1 4 0 . 1 0 0 . 1 2 0 . 1 3 0 . 1 1 0 . 1 4 0 . 1 4 0 . 1 1

8 0

6 1

8 0

4 3

4 5

4 8

4 1

5 2

5 2

6 6

4 1

3 . 7 5 6 . 4 6 4 . 5 9 6 . 0 4 3 . 9 0 3 . 3 5 3 . 5 1 4 . 2 3 3 . 5 9 3 . 9 4 3 . 5 6 3 . 3 8

f

7. 4 6

1 9

oo

0. 1 6

pr

1. 1 2

1 3. 6 8 1 6. 8 3 1 5. 1 6 1 5. 7 0 1 2. 0 9 1 4. 0 5 1 3. 6 9 1 3. 2 2 1 2. 8 3 1 3. 6 1 1 3. 4 7 1 3. 2 5

e-

EP B56

1. 2 5

1 4. 6 5 1 3. 0 7 1 3. 0 8 1 3. 2 0 1 2. 8 3 1 1. 8 8 1 1. 9 6 1 2. 7 1 1 2. 1 1 1 1. 9 7 1 2. 9 9 1 1. 9 7

Pr

EP B30

1. 0 2

na l

EP B21

4 9. 6 7 4 7. 0 7 4 6. 7 9 4 9. 0 0 5 1. 6 6 5 0. 3 2 4 9. 9 7 5 0. 5 9 5 0. 7 9 4 9. 8 9 4 9. 8 9 5 0. 4 7

Jo ur

EP B18

2 5

2 3

2 5

2 6

2 1

2 3

2 5

2 2

2 3

2 7

2 2

9. 0 7 1 5. 2 5 1 1. 4 0 1 4. 1 6 1 0. 8 7 8. 6 6 9. 1 7 1 0. 7 1 9. 3 0 9. 8 2 9. 8 3 8. 9 8

1 . 2 9 2 . 1 2 1 . 6 4 1 . 9 9 1 . 7 5 1 . 3 9 1 . 4 5 1 . 6 9 1 . 4 6 1 . 5 4 1 . 6 0 1 . 4 1

6. 3 9 1 0. 0 8 8. 2 3 9. 5 0 8. 6 1 6. 7 6 7. 0 3 8. 2 0 6. 9 9 7. 3 1 7. 8 6 6. 7 7

2 . 0 3 2 . 9 7 2 . 4 7 2 . 8 4 2 . 7 5 2 . 1 5 2 . 2 3 2 . 5 7 2 . 2 0 2 . 3 2 2 . 6 1 2 . 1 6

0 . 7 4 1 . 1 0 0 . 9 0 0 . 9 5 0 . 9 8 0 . 6 9 0 . 7 9 1 . 0 2 0 . 7 9 0 . 8 4 0 . 8 2 0 . 7 7

2 . 7 5 3 . 7 6 3 . 3 1 3 . 6 3 3 . 6 2 2 . 8 7 2 . 9 9 3 . 4 3 2 . 9 5 3 . 0 6 3 . 4 4 2 . 8 4

0 . 5 0 0 . 6 6 0 . 6 0 0 . 6 4 0 . 6 5 0 . 5 2 0 . 5 4 0 . 6 2 0 . 5 3 0 . 5 6 0 . 6 3 0 . 5 2

3 . 3 9 4 . 2 7 3 . 8 9 4 . 1 8 4 . 2 2 3 . 3 2 3 . 4 8 4 . 0 0 3 . 4 1 3 . 5 3 4 . 0 8 3 . 3 0

0 . 7 1 0 . 9 1 0 . 8 2 0 . 8 9 0 . 9 4 0 . 7 5 0 . 7 8 0 . 8 9 0 . 7 5 0 . 7 9 0 . 9 0 0 . 7 4

2 . 1 5 2 . 6 9 2 . 4 6 2 . 6 3 2 . 5 6 2 . 0 8 2 . 1 4 2 . 4 5 2 . 0 9 2 . 2 0 2 . 4 9 2 . 0 4

0 . 3 0 0 . 3 7 0 . 3 4 0 . 3 7 0 . 3 9 0 . 3 2 0 . 3 3 0 . 3 9 0 . 3 2 0 . 3 4 0 . 3 9 0 . 3 1

2 . 0 3 2 . 4 8 2 . 3 4 2 . 4 5 2 . 6 3 2 . 1 6 2 . 2 4 2 . 5 9 2 . 1 8 2 . 2 9 2 . 6 1 2 . 1 3

0 . 3 1 0 . 3 7 0 . 3 5 0 . 3 6 0 . 4 0 0 . 3 4 0 . 3 5 0 . 4 0 0 . 3 4 0 . 3 6 0 . 4 1 0 . 3 3

60

1. 0 2 1. 0 9 1. 0 9 1. 1 1 1. 2 6

0. 1 8

7. 2 9

0. 1 6

8. 3 0

0. 1 6 0. 1 9

7. 8 6 1 0. 6 6

0. 2 0

9. 0 8

0. 2 4

6. 5 4

0. 1 6

6. 3 2

1 2. 5 9 1 1. 1 9 1 2. 5 9 1 2. 0 5 1 0. 3 2 1 1. 2 8 1 2. 0 3 9. 9 5 1 2. 0 1

1. 6 4 2. 9 7 1. 8 7 1. 7 5 1. 8 2 1. 5 7 1. 7 2

0 . 8 2 0 . 5 7 0 . 2 7 0 . 9 6 0 . 1 1 0 . 1 9 0 . 2 0 0 . 1 7 0 . 2 2 0 . 1 0 0 . 2 6 0 . 1 7

0. 0 9

5 3

2 0 8

5 7

1 0 3

3 7

1 1 8

0. 1 0

5 2

2 2 1

5 0

1 1 0

2 1

1 1 2

0. 0 8

5 4

2 1 8

5 0

1 1 7

9

2 1 1

0. 0 8

5 3

2 0 5

4 6

1 1 1

4 1

1 7 8

0. 1 3

6 3

2 9 5

5 1

1 3 8

0. 0 9

5 8

2 3 9

5 1

1 2 2

0. 1 4

4 7

1 5 7

6 4

1 0 7

2. 0 3

0. 1 2

4 2

1 4 6

5 7

9 7

1. 2 4 1. 4 6 1. 0 6 1. 2 8

0. 2 0

6. 4 1

0. 1 8

7. 5 5

0. 1 8

6. 5 8

0. 1 8

6. 0 3

7. 9 8 1 0. 6 4 1 1. 5 0

1. 6 6

0. 1 1

4 4

1 3 8

6 2

1 2 8

2. 4 3

0. 1 3

4 5

1 7 1

6 9

1. 5 8

0. 1 3

4 6

1 5 2

2. 1 9

0. 1 1

4 3

1 4 6

1 . 0 4 0 . 4 0 0 . 3 8 2 . 2 8 0 . 2 1 0 . 2 2 0 . 1 3 0 . 1 3 0 . 1 1 0 . 1 0 0 . 1 6 0 . 1 4

1 2 8

4 4

2 8 8

1 4 1

4 8

3 0 1

9 5 2 3 9

0 . 1 5 0 . 1 5 0 . 1 6 0 . 1 7 0 . 2 2 0 . 2 0 0 . 3 1 0 . 2 4 0 . 2 5 0 . 3 0 0 . 2 6 0 . 2 4

5

1 5 8

9

2 4 7

3

1 7 7

4

1 4 0

3

1 5 2

9 8

3

1 0 9

6 2

1 0 4

1 1

2 0 3

6 7

1 0 5

4

1 8 0

2 . 2 7 2 . 3 2 2 . 5 9 2 . 6 3 3 . 0 0 2 . 7 8 4 . 2 0 3 . 5 4 3 . 6 7 4 . 6 7 3 . 7 4 3 . 7 5

4 5

1 . 2 5 1 . 4 4 0 . 9 8 0 . 9 5 1 . 7 0 1 . 7 5 2 . 5 8 1 . 7 4 1 . 9 3 2 . 6 3 2 . 2 0 1 . 3 5

4 2

2 8 4

4 1

2 8 1

5 1

3 9

2 7 4

7 2

4 3

2 9 4

1 3 5

3 8

3 1 2

8 0

4 1

3 0 2

1 0 8

4 2

3 1 6

3 9

5 1

2 7 5

6 0

4 1

3 1 5

7 8

4 3

3 4 8

0 . 3 4 0 . 3 7 0 . 5 4 0 . 3 7 0 . 5 1 0 . 6 7 0 . 9 0 0 . 8 4 0 . 7 2 0 . 9 4 0 . 7 3 0 . 8 0

0 . 1 1 0 . 1 9 0 . 1 7 0 . 1 5 0 . 2 2 0 . 4 5 0 . 3 1 0 . 2 4 0 . 2 3 0 . 2 7 0 . 2 7 0 . 2 7

5 2

3 6

3 5

6 1

6 5

9 3

6 3

7 1 1 0 2

8 3

4 8

3 . 7 8 3 . 8 0 4 . 1 7 3 . 5 9 3 . 9 3 4 . 3 6 6 . 2 1 4 . 5 4 5 . 8 3 5 . 4 2 5 . 7 9 5 . 8 4

f

7. 8 5

2 3

oo

0. 1 6

pr

1. 0 1

1 3. 6 3 1 3. 1 9 1 4. 0 7 1 3. 8 2 1 2. 2 0 1 3. 2 9 1 4. 3 9 1 7. 0 6 1 6. 1 6 1 8. 6 7 1 5. 3 6 1 5. 7 0

e-

1. 1 7

1 1. 9 5 1 2. 1 6 1 3. 7 7 1 3. 8 9 1 2. 2 8 1 2. 2 8 1 3. 8 4 1 3. 2 3 1 3. 1 2 1 2. 2 3 1 2. 8 3 1 3. 2 2

Pr

EP B95 EP B11 0 EP B12 2 EP B13 2 EP B13 4 EP B14 2 EP B14 3 EP B14 8 EP B15 0 EP B15 2

1. 0 9

na l

EP B87

5 0. 1 9 5 1. 1 8 4 7. 8 8 4 8. 4 1 5 1. 1 9 5 0. 9 3 4 9. 7 7 4 9. 7 0 4 8. 8 7 4 9. 2 8 5 1. 3 9 4 9. 6 3

Jo ur

EP B86

2 4

2 2

2 2

2 1

2 3

3 1

2 8

2 9

3 2

2 8

3 1

9. 4 3 9. 6 1 1 0. 5 4 9. 1 4 1 0. 5 2 1 1. 3 6 1 6. 1 0 1 1. 7 4 1 4. 1 3 1 4. 3 3 1 4. 4 2 1 4. 5 5

1 . 4 7 1 . 5 5 1 . 5 9 1 . 4 3 1 . 6 2 1 . 7 0 2 . 4 0 1 . 9 2 2 . 0 8 2 . 2 2 2 . 0 6 2 . 1 7

6. 9 8 7. 4 7 7. 3 9 7. 0 2 7. 5 4 8. 1 8 1 1. 0 1 8. 9 9 9. 6 8 1 0. 3 6 9. 8 4 1 0. 0 7

2 . 2 0 2 . 3 7 2 . 3 1 2 . 2 9 2 . 4 8 2 . 6 1 3 . 5 8 2 . 8 0 2 . 8 9 3 . 4 4 3 . 0 5 3 . 0 8

0 . 7 9 0 . 8 2 0 . 7 5 0 . 9 0 0 . 8 9 0 . 9 3 1 . 2 3 0 . 8 9 1 . 0 2 1 . 2 9 1 . 1 1 1 . 1 5

2 . 9 5 3 . 1 6 3 . 0 6 3 . 0 5 3 . 3 7 3 . 4 4 4 . 7 9 3 . 8 0 3 . 9 3 4 . 6 4 3 . 8 9 4 . 2 1

0 . 5 4 0 . 5 7 0 . 5 5 0 . 5 5 0 . 5 8 0 . 6 0 0 . 8 7 0 . 6 7 0 . 7 2 0 . 8 3 0 . 6 9 0 . 7 3

3 . 4 2 3 . 6 9 3 . 5 0 3 . 4 0 3 . 5 2 3 . 7 7 5 . 2 8 4 . 3 0 4 . 5 4 5 . 2 1 4 . 6 0 4 . 8 8

0 . 7 6 0 . 8 2 0 . 7 4 0 . 7 4 0 . 7 9 0 . 8 2 1 . 1 8 0 . 9 6 1 . 0 0 1 . 1 1 0 . 9 9 1 . 0 4

2 . 1 3 2 . 2 7 2 . 1 2 2 . 1 2 2 . 2 4 2 . 1 7 3 . 3 2 2 . 7 1 2 . 8 7 3 . 0 4 2 . 7 6 2 . 9 8

0 . 3 3 0 . 3 5 0 . 3 2 0 . 3 1 0 . 3 4 0 . 3 3 0 . 5 0 0 . 4 0 0 . 4 2 0 . 4 4 0 . 4 1 0 . 4 3

2 . 2 1 2 . 3 7 2 . 0 7 2 . 1 1 2 . 4 1 2 . 2 3 3 . 5 1 2 . 6 3 2 . 8 3 3 . 0 0 2 . 6 8 2 . 8 9

0 . 3 4 0 . 3 7 0 . 3 5 0 . 3 3 0 . 3 7 0 . 3 3 0 . 5 4 0 . 4 1 0 . 4 8 0 . 4 7 0 . 3 9 0 . 4 5

61

9. 9 4

2. 2 4

0 . 8 4

0. 0 9

5 0. 2 1

1. 3 0

1 3. 6 1

1 5. 9 9

0. 1 4

6. 3 3

1 0. 5 5

1. 1 5

0 . 6 0

0. 1 1

5 1. 3 0

1. 6 6

1 3. 8 4

1 3. 2 1

0. 1 5

6. 6 4

9. 6 3

3. 0 6

0 . 3 7

0. 1 3

4 8. 7 1

1. 2 6

1 3. 1 0

1 6. 0 7

0. 1 5

8. 2 4

1 0. 0 1

2. 0 1

0 . 3 4

0. 1 2

4 6

1 6 9

4 4

1 3 0

5 0

1 6 7

5 0

1 2 2

5 6

9 9

4 3

8 3

5 3

1 0 0

2 0

1 5 8

0 . 1 5

2 5

1 6 8

1 . 9 6

9

1 9 6

0 . 1 8

1 1 5

4 6

4 9

1 0 8

9

4 5

3 2 7

0 . 2 2

3 7

3 0 4

0 . 2 8

4 7

3 6 2

1 1 9

0 . 2 9

3 2

2 8 1

8 0

6 0

2 . 8 7

6 3

1 . 7 3

0 . 5 5

0 . 2 3

4 . 2 0

5 4

1 . 4 6

0 . 7 4

0 . 2 1

0 . 3 8

5 . 3 8

1 0 4

2 . 7 7

0 . 9 8

0 . 2 7

0 . 2 8

4 . 2 0

8 8

2 . 3 0

0 . 7 4

0 . 2 1

2 5

4 . 0 9

1 0. 7 9

1 . 6 0

7. 9 3

2 . 5 5

0 . 9 3

3 . 4 1

0 . 6 2

4 . 1 5

0 . 8 8

2 . 7 0

0 . 3 8

2 . 5 7

0 . 3 9

2 8

5 . 5 0

1 3. 8 8

2 . 0 6

9. 3 9

2 . 8 6

1 . 0 4

3 . 7 4

0 . 6 9

4 . 3 5

0 . 9 5

2 . 6 8

0 . 4 0

2 . 6 8

0 . 4 4

2 9

7 . 1 9

1 7. 4 1

2 . 5 4

1 1. 7 2

3 . 4 2

1 . 1 1

4 . 2 0

0 . 7 6

4 . 7 6

1 . 0 3

2 . 9 1

0 . 4 6

3 . 0 1

0 . 4 9

2 7

5 . 1 0

1 3. 2 2

2 . 0 3

9. 5 9

2 . 8 4

0 . 9 3

3 . 8 1

0 . 6 7

4 . 2 9

0 . 9 2

2 . 6 8

0 . 4 1

2 . 6 5

0 . 4 4

f

6. 4 6

oo

0. 2 0

pr

1 4. 8 1

e-

1 3. 7 2

Pr

1. 2 6

na l

5 0. 4 6

Jo ur

EP B16 1 EP B16 2/ N S EP B16 3/ N S EP B16 4/ N S

62

Jo ur

na l

Pr

e-

pr

oo

f

Table 2 Major element oxide (in wt. %), trace element (in ppm) and rare earth element (in ppm) concentrations of Peddavuru felsic volcanic rocks, eastern Dharwar craton, India. type I felsic volcanics F S T A e N P i i l2 2 M M C a K 2 M O O O O n g a 2 2 O g C C N R S C B S T N Z H T L C P N S E G T D H E T Y L O O O O O 5 # r o i b r s a c V a b r f h U Y a e r d m u d b y o r m b u 2 2 3 3 E P 7 1 1 1 3 1 B 1 0 5 1 0 0 1 6 3 0 5 1 0 2 2 1 0 4 2 1 3 9 2 3 0 1 0 1 0 0 0 0 0 0 0 . . . . . . . . . . . . . 1 . 9 . . . . 1 . . . 4 . . . . . . . . . . . . . . 6 0 1 3 6 0 3 3 1 9 0 3 5 3 6 6 7 2 1 3 4 4 7 0 8 1 2 . 6 6 0 7 9 5 2 1 8 1 3 0 3 0 4 6 6 1 2 1 5 9 2 4 4 0 7 1 8 7 6 0 7 5 9 3 8 5 1 8 4 4 3 0 6 5 0 8 8 7 7 3 2 5 0 5 E P 7 1 1 2 B 0 0 4 1 0 0 1 6 3 0 3 1 0 1 2 2 0 3 3 4 2 6 7 2 9 1 0 1 0 0 0 0 0 0 0 . . . . . . . . . . . . . 3 . 1 . . . . 1 . . . 4 . . . . . . . . . . . . . . 7 1 2 9 8 0 4 8 5 8 0 3 8 6 7 3 5 2 8 1 3 3 8 4 4 1 1 . 5 8 6 2 5 5 0 1 7 1 3 0 4 0 3 7 9 9 9 1 2 0 8 1 3 1 4 7 1 1 1 7 8 0 8 3 3 0 6 6 3 0 5 0 1 1 4 5 5 3 1 3 3 5 0 7 E P 6 1 1 1 3 1 B 9 0 5 1 0 0 1 7 3 0 3 1 0 0 2 4 0 3 3 4 1 7 0 2 0 1 0 1 0 0 0 0 0 0 0 . . . . . . . . . . . . . 1 . 1 . . . . 1 . . . 5 . . . . . . . . . . . . . . 7 9 2 3 7 0 4 2 0 9 0 3 9 3 7 3 6 4 4 6 8 3 4 2 2 6 5 . 0 0 8 5 7 4 2 1 8 1 4 0 4 0 6 2 4 6 3 1 1 4 7 8 4 2 6 4 0 4 4 5 6 3 4 3 5 5 2 1 6 6 7 8 6 0 8 9 6 9 5 5 6 8 9 8 E P 7 1 1 2 1 B 0 0 4 1 0 0 1 6 3 0 2 1 0 0 2 2 0 3 2 5 1 6 9 2 0 1 0 1 0 1 0 0 0 0 0 . . . . . . . . . . . . . 2 . 1 . . . . 1 . . . 7 . . . . . . . . . . . . . . 7 8 2 7 8 0 5 9 1 8 0 3 9 6 7 2 1 5 5 0 2 3 3 2 7 6 7 . 8 9 9 5 9 4 4 2 2 2 6 0 6 1 7 1 5 5 0 1 0 5 0 0 3 6 9 0 2 7 0 5 9 1 9 0 1 0 1 9 6 7 0 1 2 7 3 9 0 1 0 3 3 9 3 0 E 0 2 0 0 2 4 3 0 4 2 0 1 3 3 0 4 2 3 3 2 0 1 0 1 0 0 0 0 0 P 6 . 1 . . . . . . . . . . 1 . 2 . . . . 1 . 1 . 6 2 3 . 1 . . . . . . . . . . B 9 3 5 5 0 9 4 8 7 0 4 8 9 8 7 6 9 0 0 7 3 4 2 6 0 1 . 2 7 5 2 2 5 5 2 1 2 4 0 4 0 . 4 . 8 2 4 2 2 0 7 2 5 7 1 7 5 9 6 3 2 7 2 1 3 . 5 4 . . 6 . 0 7 5 3 9 0 9 7 7 7

63 1 0

0 1

5 8

6 4

6 . 3

2 1 . 6 6

3 6 . 0 9

3 . 4 5

1 2 . 1 8

2 . 0 7

0 . 6 1

1 . 5 4

0 . 2 2

1 . 1 6

0 . 2 0

0 . 4 9

0 . 0 7

0 . 4 8

0 . 0 8

6 . 9

2 0 . 2 1

3 4 . 7 4

3 . 2 7

1 1 . 6 2

2 . 0 6

0 . 5 9

1 . 4 6

0 . 2 1

0 . 9 8

0 . 1 6

0 . 4 9

0 . 0 7

0 . 4 7

0 . 0 7

6 . 0

2 2 . 7 3

3 8 . 4 7

3 . 5 8

1 2 . 5 7

2 . 1 1

0 . 5 8

1 . 4 8

0 . 2 1

0 . 9 5

0 . 1 6

0 . 4 9

0 . 0 7

0 . 5 0

0 . 0 7

6 . 2

1 9 . 4 9

3 4 . 2 4

3 . 2 6

1 1 . 7 3

2 . 0 3

0 . 5 3

1 . 5 1

0 . 2 1

1 . 1 2

0 . 2 0

0 . 5 0

0 . 0 7

0 . 4 8

0 . 0 8

6 . 5

2 4 . 2 3

4 2 . 2 5

3 . 9 5

1 4 . 0 4

2 . 3 6

0 . 5 6

1 . 6 0

0 . 2 3

1 . 0 7

0 . 1 7

0 . 5 2

0 . 0 8

0 . 5 1

0 . 0 8

2 . 6 4

0 . 0 2

1 . 0 2

2 . 9 0

4 . 7 2

3 . 5 7

0 . 0 8

6 5 . 8 9

0 . 3 5

1 7 . 1 8

2 . 7 0

0 . 0 2

1 . 2 4

1 . 5 3

7 . 0 5

3 . 9 6

0 . 0 8

6 6 . 7 0

0 . 3 5

1 7 . 0 0

2 . 6 2

0 . 0 2

1 . 1 4

1 . 8 7

6 . 3 4

3 . 8 6

0 . 1 0

6 7 . 3 8

0 . 3 4

1 6 . 5 8

2 . 6 3

0 . 0 3

1 . 0 5

1 . 9 7

6 . 1 2

3 . 8 3

0 . 0 7

6 8 . 7 6

0 . 3 2

1 6 . 4 8

2 . 5 4

0 . 0 2

1 . 0 1

2 . 2 6

4 . 8 1

3 . 7 3

0 . 0 8

4 3

2 . 9 1

2 . 8 7

0 . 7 0

4 8

2 . 2 8

2 . 1 5

0 . 6 4

4 6

1 . 8 4

2 . 2 0

0 . 6 5

4 4

3 . 4 7

2 . 7 3

0 . 7 1

4 4

3 . 1 2

2 . 2 7

0 . 6 9

1 . 2 4

3 . 8 0

0 . 4 9

1 2 7

3 . 9 7

2 4 . 4 1

0 . 5 1

5 . 4 2

1 2 3

3 . 9 0

2 4 . 7 3

0 . 5 0

5 . 3 5

2 1 1

3 . 1 2

3 . 6 6

0 . 4 4

4 . 8 3

1 8 8

3 . 9 5

2 4 . 6 5

0 . 4 2

5 . 2 2

5 7

1 4 0

3 6

7 7

0 . 7 6

8 6

1 . 1 7

1 2 0

0 . 9 1

9 0

1 . 5 0

2 1 0

3 . 5 9

4 2

4 1

7 9

4 . 7 4

1 3 0

3 . 1 3

1 1 . 0 0

3 . 0 4

1 5 1

3 . 9 3

1 2 . 0 0

3 . 1 1

1 5 5

3 . 9 8

1 2 . 4 9

3 . 3 0

1 3 4

3 . 1 7

1 0 . 9 9

3 . 1 8

1 4 7

3 . 6 4

1 5 . 0 0

6 . 5 2

pr

1 6 . 1 4

e-

0 . 3 4

na l

6 8 . 5 8

oo

f

9 0

Pr

2 1

Jo ur

9 2 E P B 9 4 E P B 1 0 7 E P B 1 0 8 E P B 1 0 9 E P B 1 1 4

0 . 7 2

2 . 1 8

5 . 3 8

3 . 7 6

0 . 0 7

6 7 . 6 7

0 . 2 9

1 6 . 7 2

2 . 3 6

0 . 0 2

0 . 7 9

2 . 1 4

6 . 2 1

3 . 7 2

0 . 0 8

6 7 . 7 0

0 . 2 9

1 6 . 7 8

2 . 3 5

0 . 0 2

0 . 8 2

2 . 1 3

6 . 1 3

3 . 7 1

0 . 0 8

6 8 . 1 2

0 . 2 9

1 6 . 6 0

2 . 3 8

0 . 0 2

0 . 8 0

2 . 2 5

5 . 7 9

3 . 6 8

0 . 0 8

6 9 . 0 9

0 . 2 9

1 6 . 0 9

2 . 6 4

0 . 0 2

0 . 7 6

2 . 4 1

4 . 9 8

3 . 6 2

0 . 0 8

3 8

2 . 8 5

2 . 1 8

0 . 6 6

4 0

2 . 0 3

1 . 7 2

0 . 6 2

4 1

2 . 8 0

6 2

4 8

1 8 2

0 . 9 1

0 . 7 7

1 9 7

2 . 8 6

1 . 8 1

0 . 6 3

4 0

1 . 9 7

1 . 6 4

0 . 6 1

3 6

1 3 . 0 3

2 . 9 8

0 . 6 5

4 8

4 5

5 1

2 . 5 8

0 . 3 0

oo

0 . 0 1

1 4 7

1 7 6

0 . 7 6

1 7 2

0 . 4 7

9 0

0 . 5 1

3 . 7 0

5 . 0 1

1 . 8 1

1 3 7

3 . 7 0

5 . 4 8

1 . 9 0

1 4 1

3 . 7 1

5 . 4 4

2 . 0 3

1 4 0

3 . 7 7

5 . 5 8

1 . 9 3

1 4 0

3 . 6 5

5 . 2 5

1 . 6 1

1 3 0

3 . 2 2

pr

2 . 3 0

1 8 . 7 5

0 . 3 9

4 . 4 4

1 8 0

3 . 5 2

1 9 . 8 6

0 . 4 4

4 . 4 0

1 6 4

3 . 4 5

1 8 . 9 5

0 . 4 1

4 . 5 6

1 6 2

3 . 6 1

1 9 . 3 9

0 . 3 6

4 . 3 7

3 . 6 1

e-

1 6 . 3 3

1 6 2

Pr

0 . 2 9

na l

6 8 . 9 6

Jo ur

E P B 1 4 4 E P B 1 4 5 E P B 1 4 6 E P B 1 5 1 E P B 1 5 3

f

64

5 . 6

1 4 . 8 5

2 7 . 3 8

2 . 6 7

9 . 8 3

1 . 8 0

0 . 5 0

1 . 2 4

0 . 1 8

0 . 9 8

0 . 1 8

0 . 4 4

0 . 0 7

0 . 4 6

0 . 0 7

5 . 5

1 7 . 3 1

3 0 . 9 5

2 . 9 4

1 1 . 0 1

1 . 9 3

0 . 5 4

1 . 3 6

0 . 1 9

0 . 8 9

0 . 1 5

0 . 4 5

0 . 0 7

0 . 4 7

0 . 0 7

6 . 3

1 6 . 8 8

3 0 . 3 1

2 . 9 5

1 0 . 9 9

1 . 9 2

0 . 5 8

1 . 4 0

0 . 2 0

0 . 9 3

0 . 1 6

0 . 4 8

0 . 0 8

0 . 4 8

0 . 0 8

5 . 4

1 7 . 3 2

3 0 . 8 9

3 . 0 0

1 1 . 1 2

1 . 9 5

0 . 5 6

1 . 3 8

0 . 2 0

0 . 8 8

0 . 1 5

0 . 4 4

0 . 0 7

0 . 4 6

0 . 0 7

5 . 8

1 8 . 4 7

3 2 . 5 3

3 . 1 7

1 1 . 8 4

2 . 0 7

0 . 5 6

1 . 4 4

0 . 2 0

0 . 9 0

0 . 1 6

0 . 4 6

0 . 0 8

0 . 4 7

0 . 0 7

65

0 . 2 8

1 . 2 9

4 . 2 4

4 . 1 0

0 . 0 3

7 2 . 6 9

0 . 0 6

1 5 . 3 0

1 . 4 7

0 . 0 4

0 . 2 4

1 . 3 9

4 . 8 5

3 . 9 2

0 . 0 3

7 3 . 7 1

0 . 0 7

1 4 . 8 5

1 . 6 3

0 . 0 3

0 . 2 5

1 . 3 1

4 . 0 7

4 . 0 4

0 . 0 3

7 4 . 0 2

0 . 0 6

1 4 . 3 7

1 . 6 7

0 . 0 6

0 . 2 1

1 . 4 2

4 . 2 1

3 . 9 4

0 . 0 3

7 3 . 0 3

0 . 0 5

1 5 . 7 7

1 . 1 5

0 . 0 3

0 . 1 7

1 . 0 8

4 . 6 4

4 . 0 5

0 . 0 3

2 9

5 . 6 1

0 . 9 7

0 . 6 8

2 4

1 . 1 7

0 . 3 7

0 . 5 9

2 3

2 . 5 4

0 . 6 1

0 . 6 4

2 0

2 . 7 6

0 . 5 9

0 . 6 9

2 3

1 . 0 9

0 . 3 1

0 . 6 0

1 9 0

1 4 3

1 2 4

3 . 6 4

4 0 4

2 . 6 9

1 7 5

1 5 1

1 6 7

0 . 8 7

1 . 1 1

oo

0 . 0 4

pr

1 . 3 9

1 3

e-

1 4 . 9 1

7 7

1 . 4 6

1 3 4

2 . 0 4

1 4 4

1 . 8 2

7 1

2 . 1 9

2 3 4

3 . 1 7

2 . 0 3

1 . 2 4

4 2 7

2 . 5 6

0 . 9 1

1 . 1 8

4 0 7

2 . 7 4

0 . 4 3

1 . 2 3

2 5 4

3 . 3 8

1 . 4 1

1 . 4 2

Pr

0 . 0 8

na l

7 3 . 6 4

Jo ur

E P B 6 6 E P B 1 3 5 E P B 1 3 6 E P B 1 3 7 E P B 1 3 8

f

type II felsic volcanics

1 4

1 4

1 4

1 6

8 5

1 0 0

9 0

9 3

8 9

2 . 4

3 . 2

2 . 6

2 . 8

3 . 4

2 5

2 8

2 3

2 6

2 5

1 0

1 2

1 2

1 3

1 3

1 9

2 5 . 5 7

4 8 . 6 0

4 . 8 8

1 8 . 2 5

3 . 8 3

0 . 7 1

3 . 1 8

0 . 5 1

2 . 9 4

0 . 5 7

1 . 5 8

0 . 2 5

1 . 7 4

0 . 2 8

1 9

2 1 . 5 9

4 5 . 0 8

4 . 6 9

1 8 . 1 0

3 . 8 8

0 . 6 5

3 . 1 5

0 . 5 1

2 . 6 1

0 . 4 7

1 . 5 6

0 . 2 6

1 . 7 2

0 . 2 8

1 8

2 0 . 1 3

4 0 . 5 0

4 . 2 0

1 6 . 6 4

3 . 6 8

0 . 7 7

3 . 0 7

0 . 4 7

2 . 7 3

0 . 5 2

1 . 4 4

0 . 2 2

1 . 5 6

0 . 2 4

2 0

2 2 . 6 6

4 5 . 5 9

4 . 7 1

1 8 . 0 1

3 . 9 7

0 . 7 8

3 . 3 0

0 . 5 1

2 . 9 9

0 . 5 8

1 . 5 8

0 . 2 5

1 . 7 9

0 . 2 8

1 9

2 5 . 5 7

4 8 . 6 0

4 . 8 8

1 8 . 2 5

3 . 8 3

0 . 7 1

2 . 8 8

0 . 5 0

2 . 6 5

0 . 4 8

1 . 5 9

0 . 2 7

1 . 8 3

0 . 2 8

0 . 2 3

1 . 0 8

5 . 1 6

4 . 1 0

0 . 0 3

7 2 . 8 1

0 . 0 6

1 5 . 0 5

1 . 4 9

0 . 0 5

0 . 2 3

1 . 3 5

4 . 9 8

3 . 9 4

0 . 0 3

7 4 . 2 4

0 . 0 5

1 4 . 3 7

1 . 1 8

0 . 0 4

0 . 1 4

0 . 9 9

4 . 8 1

4 . 1 4

0 . 0 3

7 3 . 2 3

0 . 0 5

1 4 . 3 2

1 . 1 8

0 . 0 4

0 . 1 4

0 . 8 2

6 . 0 3

4 . 1 5

0 . 0 3

2 2

1 . 5 9

0 . 5 4

0 . 6 1

2 3

1 . 2 7

0 . 3 8

0 . 6 0

1 9

1 . 4 9

1 9

2 . 4 4

1 3 1

1 4 7

9 1

1 . 4 5

1 . 7 2

2 6 1

3 . 2 7

0 . 3 8

0 . 6 0

0 . 5 9

0 . 6 6

1 6 6

1 0 2

5 . 0 2

1 . 1 5

oo

0 . 0 3

8 2

8 3

2 . 6 2

8 7

0 . 8 3

1 4

1 0 3

3 . 3

2 8

1 3

1 9

2 4 . 9 2

4 8 . 7 6

5 . 0 0

1 9 . 4 5

4 . 0 9

0 . 7 3

3 . 2 6

0 . 5 2

2 . 6 6

0 . 4 7

1 . 5 4

0 . 2 6

1 . 6 9

0 . 2 7

1 9

2 6 . 9 5

5 2 . 8 3

5 . 3 2

2 0 . 4 0

4 . 2 0

0 . 7 1

3 . 3 6

0 . 5 2

2 . 5 8

0 . 4 7

1 . 5 3

0 . 2 6

1 . 6 8

0 . 2 7

1 9

2 8 . 3 9

5 1 . 7 2

5 . 1 4

1 9 . 0 9

3 . 9 5

0 . 8 3

2 . 9 4

0 . 4 9

2 . 6 1

0 . 4 7

1 . 5 3

0 . 2 6

1 . 6 7

0 . 2 6

2 2

1 9 . 8 9

3 7 . 9 3

3 . 7 6

1 4 . 1 1

3 . 4 3

0 . 6 4

2 . 8 4

0 . 5 3

3 . 1 4

0 . 6 2

1 . 6 9

0 . 2 6

1 . 8 2

0 . 2 7

pr

1 . 6 5

3 . 5 5

1 . 9 6

1 . 4 5

2 7 1

3 . 3 0

1 . 9 2

1 . 5 0

3 3 3

2 . 2 9

1 . 4 2

1 . 2 2

e-

1 4 . 4 9

2 4 4

Pr

0 . 0 6

na l

7 3 . 1 5

Jo ur

E P B 1 3 9 E P B 1 4 0 E P B 1 4 1 E P B 1 4 9

f

66

1 5

1 5

1 4

1 0 1

8 1

7 7

3 . 3

3 . 1

2 . 2

3 0

2 4

1 8

1 3

1 3

1 0

67

45

31.800

31.915

0.765

44.000

43.848

0.537

51

317.000

318.343

1.025

313.000

324.096

0.535

53

289.000

289.785

1.245

382.000

395.877

0.203

59

45.000

45.066

0.134

51.400

52.843

60

121.000

120.898

0.494

166.000

63

136.000

135.980

0.695

66

105.000

104.017

71

21.000

85 88 89 90 93

Ni Cu Zn Ga Rb Sr Y Zr Nb

5.069

5.041

1.046

7.900

7.862

1.412

3.093

3.065

0.837

2.300

2.251

1.924

3.148

3.050

2.420

0.376

0.650

0.637

1.441

0.479

0.461

2.978

167.815

1.160

0.660

0.657

1.121

0.724

0.712

1.565

126.000

127.023

1.808

1.400

1.386

0.831

1.983

1.940

1.691

1.250

71.000

74.154

5.335

30.000

29.748

0.690

27.447

27.199

0.803

21.024

1.382

16.000

15.319

0.933

17.600

17.546

0.586

18.051

18.201

0.602

11.000

11.012

0.822

0.250

0.265

0.884

257.000

258.547

0.520

306.067

305.429

1.141

403.000

402.642

0.163

108.000

121.311

3.306

30.000

30.076

0.386

17.060

16.886

0.780

27.600

27.533

0.310

16.000

16.596

0.992

45.400

45.444

0.417

50.522

50.554

0.486

179.000

179.278

0.137

15.500

21.701

0.955

101.000

101.431

0.364

95.688

95.648

0.248

19.000

19.000

0.071

0.600

0.718

3.756

15.500

15.506

0.532

18.161

18.205

0.325

5.032

0.005

0.071

4.763

20.200

20.049

0.507

25.196

25.085

0.813

1.217

7.000

7.282

1.223

40.000

40.072

1.217

32.185

31.383

1.835

0.981

0.620

0.866

5.519

19.700

19.631

0.264

15.161

15.096

1.053

pr

Co

%RSD

1.134

e-

Cr

JR-2 B

5.083

Pr

V

A

5.160

na l

Sc

oo

f

Table 3 Relative standard deviation (RSD) obtained for the measured elements in the certified reference materials. BHVO1 BIR-1 JR-1 Sample A B %RSD A B %RSD A B %RSD

Cs

0.130

0.132

137

Ba

139.000

137.664

139

La

15.800

15.718

140

Ce

39.000

38.774

0.646

1.950

2.368

5.861

47.100

46.946

0.510

37.720

37.552

0.522

141

Pr

5.700

5.681

0.598

0.380

0.494

2.834

5.620

5.596

0.697

4.534

4.555

0.987

146

Nd

25.200

25.050

0.634

2.500

2.926

5.044

23.500

23.305

0.792

19.353

19.207

1.261

147

Sm

6.200

6.084

1.663

1.100

1.451

4.840

6.070

6.028

0.997

5.563

5.569

1.235

153

Eu

2.060

2.053

1.217

0.540

0.617

4.427

0.300

0.299

0.914

0.118

0.120

3.018

157

Gd

6.400

6.382

1.321

1.850

2.079

2.438

5.240

5.190

0.810

5.152

5.100

1.850

159

Tb

0.960

0.954

1.095

0.360

0.409

4.081

1.020

1.013

1.153

1.070

1.062

0.987

163

Dy

5.200

5.208

1.387

2.500

2.685

2.670

5.780

5.769

0.927

6.193

6.151

0.685

Jo ur

133

68

Ho

0.990

0.980

0.921

0.570

0.603

1.365

1.100

1.094

0.432

1.206

1.197

0.978

166

Er

2.400

2.381

2.633

1.700

1.717

2.127

3.780

3.748

0.775

4.187

4.159

0.752

169

Tm

0.330

0.326

2.659

0.260

0.256

4.670

0.670

0.667

0.766

0.756

0.755

1.456

172

Yb

2.020

2.036

1.311

1.650

1.691

3.776

4.490

4.486

0.769

5.104

5.081

0.343

175

Lu

0.290

0.291

0.693

0.260

0.260

5.599

0.710

0.704

0.712

0.817

0.817

1.284

178

Hf

4.380

4.335

1.144

0.600

0.927

4.038

4.670

4.656

1.120

5.026

5.001

0.700

181

Ta

1.230

1.241

1.278

0.040

0.142

9.677

1.900

1.898

0.130

2.300

2.305

0.796

208

Pb

2.600

2.581

1.358

3.000

2.979

7.989

19.100

19.042

0.628

18.350

17.960

1.497

232

Th

1.080

1.097

1.397

0.030

0.032

0.053

26.500

26.322

0.614

31.269

31.083

0.669

U 0.420 0.420 0.516 0.010 0.011 2.101 9.000 8.900 0.797 11.273 A – values from Govindaraju (1994) and GEOREM (georem.mpch-mainz.gwdg.de); B – values from HR-ICP-MS (average of 6 values)

11.195

0.705

Jo ur

na l

oo

pr

e-

Pr

238

f

165

69 Table 4 Geochemical composition of the basalts from major greenstone belts of the eastern Dharwar craon, India. Kadiri4 52.75 0.93 14.52 11.28 0.18 6.70 10.91 2.18 0.38 0.17 54

Hutti5 49.23 1.09 11.65 13.66 0.19 10.51 10.25 2.06 0.18 0.10 63

192 107 15 144 42 299 3.0 59 0.58 24

184 132 15 176 30 266 2.9 50 0.47 24

197 122 27 117 42 332 3.0 64 0.37 27

203 133 8 163 52 374 4.1 59 0.62 27

615 164 3 153 42 322 3.9 35 0.49 26

Kushtagi6 49.50 0.83 11.56 13.31 0.21 11.05 10.53 1.65 0.29 0.08 65

Penakacherla7 50.43 0.66 13.76 11.72 0.18 8.81 11.28 1.99 0.30 0.05 62

880 165 12 124 38 276 3.08 23 0.47 24

457 147 13 130 59 368 1.7 38 0.17 16

ur

na

lP

La 4.43 4.06 4.10 5.68 4.01 8.16 2.03 Ce 11.13 10.60 10.78 14.15 10.99 12.82 5.60 Pr 1.69 1.64 1.67 2.13 1.41 3.69 0.89 Nd 8.08 7.76 8.18 9.84 8.99 9.31 4.56 Sm 2.52 2.48 2.65 2.93 2.70 3.62 1.53 Eu 0.90 0.87 0.99 1.04 1.00 0.99 0.60 Gd 3.34 3.06 3.42 3.61 3.82 3.41 2.23 Tb 0.60 0.57 0.64 0.65 0.69 0.39 Dy 3.87 3.77 4.28 4.25 3.97 3.23 2.73 Ho 0.84 0.83 0.95 0.95 0.83 0.60 Er 2.40 2.25 2.61 2.53 2.66 1.96 1.81 Tm 0.36 0.36 0.40 0.40 0.45 0.27 Yb 2.39 2.36 2.74 2.66 2.34 1.92 1.78 Lu 0.37 0.37 0.43 0.41 0.33 0.36 0.27 1* = This study; 2 = Manikymaba and Khanna (2007) & Khanna (2013); 3 = Khanna et al. (2015); 4 = Manikyamba et al. (2015); 5 = Manikyamba et al. (2009); 6 = Naqvi et al. (2006); 7 = Manikyamba et al. (2004); 8 = Manikyamba et al. (2008)

Jo

Sandur8 51.53 0.78 12.82 11.78 0.21 8.88 9.35 2.93 0.40 0.07 62

ro of

Veligallu3 49.41 1.10 12.30 15.26 0.20 9.32 9.87 1.75 0.68 0.12 55

re

Cr Ni Rb Sr Sc V Nb Zr Th Y

Gadwal2 51.61 0.89 13.63 12.76 0.16 7.35 10.94 2.34 0.23 0.09 53

-p

SiO2 TiO2 Al2O3 Fe2O3 MnO MgO CaO Na2O K2O P 2O 5 Mg#

Peddavuru1* 49.23 1.16 13.13 14.48 0.16 7.75 11.47 2.06 0.45 0.10 51

581 142 35 117 47 319 3.5 45 0.50 20 3.35 8.86 1.34 6.39 1.96 0.77 2.78 0.48 3.21 0.70 2.04 0.32 2.00 0.29