Himalayan Geology, Vol. 40 (1), 2019, pp. 58-66, Printed in India
Microstructural evolution of the garnet metapellites near Sawantwadi, Sindhudurg District, Maharashtra
DASHPUTRE A.S.1*, PRADEEP B. JADHAV2, MARATHE T.1
1Department of Geology, Fergusson College, Pune, 411004
2Department of Petroleum Engineering, Maharashtra Institute of Technology, Pune, 411038, India
*Email (Corresponding Author): dashputreamey@gmail.com
Abstract: Oriented thin sections of garnet bearing metapellites belonging to the supracrustal sequence exposed near Sawantwadi taluka of Sindhudurg district of coastal Maharashtra have been studied in detail. The regional and meso- scale field investigations helped infer three ductile deformational events (D1, D2 and D3) in the study area giving rise to hook shaped folds (Type III interference pattern). The analysis of oriented thin sections, photomicrographic mosaics (manually prepared) and the stable mineral assemblages of garnet, biotite, muscovite, chlorite, quartz and some feldspar identified from thin sections indicate garnet zone of metamorphism for the metapellites. This analysis has also pointed out to the evolution of garnet from biotite by prograde metamorphism during the successive metamorphic events. Formation of biotite and chlorite from garnet by retrograde metamorphism at the end of third deformational event is also observed. A strong structural overprint and a complex deformation history is revealed by the analysis and synthesis of Macro-, Meso- and Micro- scale observations of the supracrustal rocks in the present study area.
Key words: Sawantwadi, Supracrustal rocks, Metapellites, Deformation and metamorphism, Thin Sections, Photomicrographs.
