The Lower Paleozoic Granitic Magmatism Near Ranikhet, Kumaun Himalaya: Major and Trace-Element Geochemistry and Tectonic Setting

The Lower Paleozoic Ranikhet granitic rocks lie in between the tectonically active South and North Almora thrust zones and contain two types of granites: a Gneissose granite (GG) and a younger Porphyritic granite (PG). Both the phases show a good correlation in some of the major elements, whereas a wide scatter is observed in the trace-elemental abundances. These Ranikhet granites are Rb rich and Sr poor, they reveal peraluminous characteristics and correspond to the S-type granites. A syn-collisional tectonic environment for these granites is revealed by their Nb+Y and Rb concentration. Lower Paleozoic granites reported all along the Lesser Himalayan belt extending from Munsehra, NW Himalaya to Palung, Nepal Himalaya represent the widespread magmatic activity around the end of the Cambrian times. These granites support for the exitence of a syn-collisional tectonic environment in the early Paleozoic period.