Articles | Volume 9, issue 5
Research article
22 Oct 2018
Research article |  | 22 Oct 2018

Permian plume beneath Tarim from receiver functions

Lev Vinnik, Yangfan Deng, Grigoriy Kosarev, Sergey Oreshin, and Larissa Makeyeva

Abstract. Receiver functions for the central Tien Shan and northern Tarim in central Asia reveal a pronounced depression on the 410 km discontinuity beneath the Permian basalts in Tarim. The depression may be caused by elevated temperature. The striking spatial correlation between the anomaly of the MTZ and the Permian basalts suggests that both may be effects of the same plume. This relation can be reconciled with the possible motion of Tarim on the order of 1000 km by assuming that the mantle layer, which has moved coherently with the plate since the Permian, extends to a depth of 410 km or more. Alternatively, the lithosphere and underlying mantle are decoupled at a depth of  ∼ 200 km, but a cumulative effect of the Tarim plate motion since the Permian is less by an order of magnitude. A similar explanation is applicable to the Siberian traps.

Short summary
We used seismology data to estimate the thickness of the MTZ and found it thinned beneath Tarim, which is exactly beneath the Permian basalts. This relation can be reconciled with coherent translation of a tectosphere that extends to a depth of 410 km or more. Combined with observations in the Siberian large igneous province and Greenland, these features may confirm the existence of a deep tectosphere. Alternatively, the shift of Tarim is less than predicted by an order of magnitude.