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Authors
Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Bangalore - 560 072, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 62, No 2 (2003), Pagination: 152-168
Abstract
The late Archaean Closepet Granite of the Gudur-Guledagudda area consists of equigranular pink and grey biotite granites, and porphyntic pink biotite granodionte to quartz-monzodionte. The granitoids exhibit intrusive relation with the Hungund-Kushtagi schist belt at places. The equigranular granites show limited range of major oxide compositions and compared to the porphyntic granodionte and quartz-monzodionte, are enriched in Si02, K20 and Rb but depleted in Al203, FeO, Fe203, CaO, MgO, P205, Sr, Ba, Y, Nb and REE. The granitoids fall near the boundary between peraluminous and metaluminous granitoids with the A/CNK ratios around one Fractionated LREE and flat HREE patterns and a negative Eu anomaly characterize all the samples Field evidences indicate mainly post-kinematic nature of the granitoids. The equigranular granites appear to be minimum melt derived from anatexis of Peninsular Gneiss without fractional crystallization. The porphyntic granodionte and quartz-monzodionte represent non-minimum melt derived from a different source enriched in REE Geochemical signatures indicate that the Closepet Granite of Gudur-Guledagudda area is the product of melting at shallower level compared to the southern Closepet Granite.
Keywords
Petrography, Geochemistry, Northern Closepet Granite, Gudur-Guledagudda Area, Karnataka.
