Abstract

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

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.