Field and Petrographic Studies of the Guwahati Metapelites, Assam, NE India: Evidence for Post- Metamorphic K-Metasomatism

In this study, we report mineralogical features of post-metamorphic K-metasomatic assemblage high-grade metapelites from Guwahati, the northern extension central part Shillong Plateau, NE India. Several reaction textures metasomatic are shown and they offer clues for relevant reactions modification pre-metasomatic metapelites. Two sets mineral recognized, which include, alteration high-temperature all kinds aluminium-silicate phases into low-grade minerals replacement coexisting metamorphic plagioclase quartz by K-feldspar due to involvement K-rich fluids at end deformational events. Our structural study indicates rocks area intensely deformed with multiple folding events post-kinematic shearing faulting cross-cut dominant foliation rocks. The deep-seated moved shear zones migrated along plane, grain boundaries transforming parent As a result changes, pre-existing disappear turn -rich granitic rock.