Peridotite and pyroxenite xenoliths from Tarim, NW China: Evidences for melt depletion and mantle refertilization in the mantle source region of the Tarim flood basalt

Mantle-derived spinel peridotite and spinel plagioclase pyroxenite xenoliths hosted in Cenozoic alkali basalts (20 Ma) are found in the Xikeer area, western Tarim Block, NW China. Based on petrographic and geochemical characteristics, the peridotite xenoliths are divided into three groups. Group 1 peridotite xenoliths have experienced high degree melt extraction (~ 17% fractional melting) and weak, incipient metasomatism. Group 2 and 3...