Abstract

The present study is carried out to probe geodynamic evolution and tectonic history of A-type granitoids from the Riwasa and Nigana areas in the Tusham Ring Complex (TRC), western Peninsular India on the basis of petrological and geochemical aspects. The investigated rocks have the characteristics of hypersolvus, calc-alkaline, peraluminous and A-type granitoids. They are enriched in SiO₂, Na₂O+K₂O, Fe/Mg, Th, U, REE (except Eu), LILE+HFSE, elevated in Fe/Mg, Ga/Al, Th/U, A/CNK ratios, and depleted in CaO, MgO, Sr, Cr, Ni, P, and Ti, and having Eu abundances. They also show high heat production (HHP) affinity and high mineralization potential. Elemental geochemistry in conjunction with mineralogical variants attested that they were formed by limited fractional crystallization of a parental magma derived from partial melting of crustal protolith accreted during the Neoproterozoic magmatic event. Physicochemical features i.e. F and Cl-rich biotite, pegmatite rim, substantial model content of albite, high mineralized veins and altered mineralogy indicate rock-fluid interactions which are caused by magmatic origin or secondary metasomatic alteration superimposed on the host rock. The magmatism occurred in the TRC is interpreted to represent the Malani Igneous Suite (MIS) and their linkage with Rodinia Supercontinent and Pan-African thermal event.

中文翻译：

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Tusham环复合体（西北印度盾）的新元古代岩浆作用的岩石成因及其构造意义：对马拉尼火成岩套件和罗丹尼亚超大陆的构造演化的认识

摘要

根据岩石和地球化学方面的研究，本研究旨在探讨印度西部印度半岛Tusham Ring Complex（TRC）的Riwasa和Nigana地区A型花岗岩的地球动力学演化和​​构造历史。被研究的岩石具有超溶质，钙碱性，铝质和A型花岗岩的特征。它们富含SiO ₂，Na ₂ O + K ₂O，Fe / Mg，Th，U，REE（Eu除外），LILE + HFSE，Fe / Mg，Ga / Al，Th / U，A / CNK比升高，CaO，MgO，Sr，Cr耗尽Ni，P和Ti，并具有Eu丰度。它们还显示出高产热（HHP）亲和力和高矿化潜力。元素地球化学与矿物学变体一起证明，它们是由新元古代岩浆事件中所积聚的地壳原生岩部分熔融而产生的母岩浆有限分级结晶形成的。富含F和Cl的黑云母，伟晶岩边缘，钠长石的大量模型含量，高矿化脉脉和改变的矿物学等理化特征表明，岩浆流体相互作用是由岩浆成因或叠加在主体岩石上的次生变质作用引起的。