The Buqingshan Complex, the eastern part of the Muztagh–Buqingshan–Anemaqen ophiolitic mélange zone (MBAM), contains a series of oceanic rocks that represent the remnants of the Paleo-Tethys Ocean. Field investigations reveal that the mafic-ultramafic rocks consist mainly of serpentinite, diabase, massive basalt, and pillow basalt. The serpentinites show similar geochemical characteristics to abyssal peridotites, which is probably the residual part of the depleted upper mantle after 17–20% melt extraction. The mafic rocks have geochemical affinities similar...