Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

Anupam Chattopadhyay ¹, A. S. Khan ¹, A. K. Huin ¹, B. K. Bandyopadhyay ¹

Affiliations
1 Geological Survey of India, Seminary Hills, Nagpur 440 006, IN

Abstract

Geological mapping and structural analysis of the manganese-bearing Sausar Group and associated rocks in Ramtek-Mansar-Kandri area, Maharashtra, have led to reinterpretation of stratigraphy and structure. A local stratigraphic succession for the Sausar supracrustal rocks, giving due weightage to lithologic critena and structural considerations, has been proposed which is different from the existing divergent lithostratigraphic successions suggested by different workers at different times. The lithologic unit interpreted as a conglomerate horizon by some earlier workers, near the contact of the granite gneiss and the Sausar Group in Mansar-Kandri area, has been reintmpreted to be of tectonic origin, Sausar Group preserves evidence of four generations of folding (F₁ to F₄). The map pattern is controlled by F₂ and F₄ whereas F₁ and F₃ have developed only on hand specimen to outcrop scale Ramtek synform, the major structural feature in the area, is a polyharmonic, second-generation fold with shallow southeasterly plunge and a steep to subvertical, WNW-ESE striking axial plane. It is not a large scale non-plane, non-cylindrical superposed fold (F₂ on F₁), as interpreted earlier. Regional metamorphism of pelitic-psammopelitic rocks possibly reached amphlbolite facies with peak metamorphic condition post-dating D₁ deformation.

Keywords

Sausar Group, Structure, Stratigraphy, Folding, Metamorphism, Maharashtra, Central India.

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Abhinaba Roy ¹, B. K. Bandyopadhyay ¹, A. K. Huin ¹

Affiliations
1 Geological Survey of India, Central Region, Nagpur - 440006, IN

Abstract

The Mafic volcanic suite exposed mainly in the eastern part of the Sakoli schist belt comprises the lower part of the Sakoli sequence. The samples are tholeiitic in composilion having moderate M-values (45-62) and lower abundances of Ni, Co and Cr indicative of evolved nature of the magma. Certain major and trace element characteristics and LREE enriched REE patterns suggest magma derivation by low degrees of partial melting of komatiite-like sources.

Keywords

Sakoli Schist Belt, Geochemistry, Komatiites, Maharashtra.

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