Complex protolith origin of serpentinized peridotites from the shergol ophiolitic slice North-Western ladakh himalaya, Jammu and Kashmir, India

The serpentinized peridotites, associated with blueschists of ocean island basalt/gabbro origin in Shergol Ophiolite slice northwestern Ladakh Himalaya are discussed in this paper. Most studied serpentinized peridotites have low Al/Si and high Mg/Si ratios in bulk rock compositions than primitive mantle, reflecting a refractory abyssal mantle peridotite protolith however, the two samples under study contain high Al/Si and low Mg/Si ratios compared to primitive mantle, signifying their ultramafic, cumulate protolith nature. REE modelling suggests that the Shergol peridotites of refractory nature represent mantle residues leftover after less than 15% partial melting whereas, the Shergol peridotites of a cumulate nature represent solidified melts located at the base of an oceanic crust in the context of Mesozoic NeoTethys ocean.