Magmatism in western Cuddapahs: The mafic sills and lava flows of Vempalle and Tadpatri formations

Chakraborty, Kushal; Mukhopadhyay, P. K.; Pankaj, Praveer

doi:10.1007/s12594-016-0438-1

Cited by 12 publications

(9 citation statements)

References 39 publications

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“…Within the Vempalle Formation, the mafic magmatic rocks are associated with stromatolitic carbonates, cherts, and shales that are suggested to be deposited in a shallow marine environment (Khelen et al, ). Geochemical and geochronological studies on the extrusive and intrusive mafic rocks exposed in the Vempalle Formation have been reported by few earlier workers (Anand, Gibson, Subbarao, Kelley, & Dickin, ; Chakraborty, Mukhopadhyay, & Pankaj, ; Dhanakumar et al, 2018; French, Heaman, Chacko, & Srivastava, ; Sheppard et al, ). In this paper, we document the PGE geochemistry along with major and trace elements systematics of mafic sills from the Vempalle Formation to evaluate their sulphur saturation history, source heterogeneity, and tectonic setting.…”

Section: Introductionmentioning

confidence: 83%

Platinum group element geochemistry and whole‐rock systematics of the Vempalle sills, Cuddapah Basin, India: Implications on sulphur saturation history, mantle processes, and tectonic setting

Singh

Manikyamba

2019

Geological Journal

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The intracratonic Cuddapah Basin of southern peninsular India has multiple phases of magmatism exposed as mafic intrusives and extrusives in the Vempalle and Tadpatri formations. We report platinum group element geochemistry along with whole‐rock systematics of the mafic sills from the Vempalle Formation to understand their sulphur saturation history, source characteristics, and tectonic setting. These sills are medium‐ to fine‐grained dolerites with plagioclase and pyroxenes as essential minerals exhibiting sub‐ophitic to intergranular texture. Geochemically, they are characterized by moderate MgO (6.3–8.5 wt.%), Ni (55–105 ppm), Cr (20–130 ppm), and ∑PGE (22–61 ppb) contents and exhibit transitional to calc‐alkaline in nature. Primitive mantle‐ and chondrite‐normalized trace and rare earth element patterns display relative enrichment of LILE–LREE over HFSE, suggesting plume‐related intraplate magmatism with contributions from subcontinental lithospheric mantle (SCLM), lithosphere–asthenosphere interaction, crustal contamination, and fractional crystallization. Their REE relationship indicates the generation of parent magma from a heterogeneous source marked by 10–25% polybaric partial melting within spinel and garnet lherzolite domain. Platinum group elements (PGE) geochemistry reveals their sulphur‐undersaturated nature, and sulphide fractionation played a key role in the distribution of PGEs, which is evidenced by their enriched character, moderate degrees of partial melting, and crustal contamination. Further, the negative platinum anomalies in these sills indicate its removal during fractional crystallization, and the enrichment of Pd over Pt endorses the decoupling nature of these elements prior to their emplacement. Diagnostic trace element signatures and their relationship corroborate a riftogenic intraplate tectonic regime for the emplacement of the Vempalle sills through an ocean–continent transition zone.

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Section: Introductionmentioning

confidence: 83%

Platinum group element geochemistry and whole‐rock systematics of the Vempalle sills, Cuddapah Basin, India: Implications on sulphur saturation history, mantle processes, and tectonic setting

Singh

Manikyamba

2019

Geological Journal

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“…Several dolerite sills and basaltic lava flows are present within the Tadpatri Formation (Chakraborty et al, 2016). Chilled margins of the dolerite and contact metamorphic effect in the host carbonates are commonly seen.…”

Section: Tadpatri Formationmentioning

confidence: 98%

“…Suspected volcaniclastics interbedded within the Nallamalai Group and volcanogenic cherts in the limestones of Kurnool Group are potential exceptions to this statement, awaiting confirmation from future studies. Chakraborty et al (2016) had attributed partial melting of spinel -garnet peridotite for Vempalle lava flows. Singh et al (2018) studied six basaltic lava flows from the Vempalle Formation.…”

Section: Interbedded Igneous Rocksmentioning

confidence: 99%

“…They suggested sulphur-saturated nature of magmas in a riftcontrolled intraplate setting associated with an oceancontinent transition zone for the emplacement of these lava flows based on PGE chemistry. Chakraborty et al (2016) distinguished five varieties of sills intruding the Tadpatri Formation based on petrographic and geochemical studies. They inferred that the mafic sills of Tadpatri Formation are derived from small scale localized melting of the contaminated mantle in a rift setting.…”

Section: Interbedded Igneous Rocksmentioning

confidence: 99%

See 1 more Smart Citation

Cuddapah Basin, India: A Collage of Proterozoic Subbasins and Terranes

Kale¹,

Saha²,

Patrabnis-Deb³

et al. 2020

PINSA

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The sedimentary sequences and associated magmatic rocks from the Cuddapah basin and adjoining fold belts on the eastern margin of the Dharwar craton of Peninsular India are repositories of several economic mineral deposits, including radioactive mineral deposits. Growing evidence suggests that the array of subbasins (on the western side), the Nallamalai Fold Belt, and the eastern Nellore Schist Belt represent independent terranes that were tectonically connected. Paleoproterozoic-Mesoproterozoic extensional passive margin development with the attached oceanic realm, followed by Mesoproterozoic collisional tectonics and a subsequent Neoproterozoic extensional regime resulted in the present configuration of this region. A review of recent publications suggests that several traditional views deserve to be modified. This region needs to be examined in light of the emerging models of Proterozoic supercontinental assembly and break-up. Open areas of debate and gaps in confirmatory evidence for such models are discussed to provide directions for future studies.

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“…Tadpatri sills are relatively unaltered in nature, consists of olivine, pyroxene, phlogopite and some spinel. The lower part of the sills shows cumulate texture with fresh olivine, while the upper part of 1 2 3 4 5 6 7 8 9 10 11 12 Standard NIM-S GSR-2 JSL-1 GSR-5 JA-2 GSR-7 SARM-50 NIM-P JB-3 JGb-2 GSI-SA-1 GSR-3 (Chakraborty et al 2016).…”

Section: Papaghni Group Vempallimentioning

confidence: 99%

Petrology and geochemistry of mafic dyke and sills in Cumbum Formation, of the Proterozoic Nallamalai fold belt, Rajampet area, Andhra Pradesh, India

Das

Chakraborty

2019

J Earth Syst Sci

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Intensely deformed Proterozoic Nallamalai fold belt (NFB) occupies the eastern part of undeformed, Proterozoic Cuddapah basin and is separated from Cuddapah basin by easterly dipping Rudravaram thrust line. Igneous activity in NFB is represented by intrusive syenite and lamproite dykes. This study brings out the petrological and geochemical character of unreported intrusive dolerite dykes and sills within the Cumbum Formation of NFB. The dykes are undeformed, whereas the sills suffered D1 phase of deformation, although both are petrologically and geochemically similar. The rocks are highly fractionated sub-alkaline tholeiite, consist mainly of clino-pyroxene and plagioclase. Chondritenormalised rare earth element (REE) plot shows enriched light rare earth element (LREE) and flat heavy rare earth element (HREE). A primitive mantle-normalised multi-element spider diagram shows troughs in Nb, Ta, Ti and Zr indicating subduction zone character. Tectonic discrimination plots indicate both within-plate and subduction zone environment of formation. Geochemical modelling also indicates enriched spinel peridotite as a probable source for dykes and sills. We suggest that the lithospheric mantle beneath NFB got enriched by subduction-derived fluid around 1.6 Ga, and in later stage, these dykes and sills were generated by extension of the enriched lithosphere at different phases in turn inheriting the subduction zone geochemical characters.

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Magmatism in western Cuddapahs: The mafic sills and lava flows of Vempalle and Tadpatri formations

Cited by 12 publications

References 39 publications

Platinum group element geochemistry and whole‐rock systematics of the Vempalle sills, Cuddapah Basin, India: Implications on sulphur saturation history, mantle processes, and tectonic setting

Platinum group element geochemistry and whole‐rock systematics of the Vempalle sills, Cuddapah Basin, India: Implications on sulphur saturation history, mantle processes, and tectonic setting

Cuddapah Basin, India: A Collage of Proterozoic Subbasins and Terranes

Petrology and geochemistry of mafic dyke and sills in Cumbum Formation, of the Proterozoic Nallamalai fold belt, Rajampet area, Andhra Pradesh, India

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