Permian plume-strengthened Tarim lithosphere controls the Cenozoic deformation pattern of the Himalayan-Tibetan orogen

The high strength of the Tarim Basin (northwestern China) lithosphere, widely regarded as a Precambrian craton, is evidenced by its resistance to Cenozoic deformation in the Himalayan-Tibetan orogen. However, Neoproterozoic suturing and early Paleozoic shortening within the Tarim Basin suggest that its rigidity is a relatively recent phenomenon with unknown cause. We reprocessed high-resolution magnetic data that show a 300-400-km-diameter radial pattern of linear anomalies emanating from a central region characterized by mixed positive-negative anomalies. We suggest that this pattern was generated by the previously hypothesized Permian (ca. 300-270 Ma) plume beneath the Tarim Basin. Constrained by published geochemical and geochronological data from plume-related igneous rocks, we propose that the similar to 30 m.y. Permian plume activity resulted in a more viscous, depleted, thicker, dehydrated, and low-density mantle lithosphere. The resulting stronger lithosphere deflected strain from the Cenozoic India-Asia convergence around Tarim Basin, including Pamir overthrusting to the northwest and Altyn Tagh left-slip displacement to the northeast, thus shaping the geometry of the Himalayan-Tibetan orogen.