Article ID Journal Published Year Pages File Type
6440472 Lithos 2016 73 Pages PDF
Abstract
Whole-rock Os isotopic compositions of the Purang peridotites give ancient TRD model ages (up to 1.3 Ga), indicating that the formation of these ancient depletion residues predated the opening of Neo-Tethyan Ocean. These observations, together with recent studies on other IYZ peridotites, suggest that the Purang peridotites are genetically unrelated to the associated mafic crust. Instead, they represent ancient SCLM domains, initially formed beneath a continental margin, and then modified by subduction, before they were incorporated into the Neo-Tethyan ocean basin. This model is consistent with the deep-mantle-recycling model for the presence of SuR-UHP phases in the IYZ ophiolites. The infiltration of MORB melts through these ancient depleted peridotites during their final exhumation in a (ultra-) slow-spreading center may have refertilized them to produce the clinopyroxene-rich peridotites.
Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Geochemistry and Petrology
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