Magnetostratigraphy of Cenozoic deposits in the western Qaidam Basin and its implication for the surface uplift of the northeastern margin of the Tibetan Plateau

摘要

Thick Cenozoic deposits in the northwestern Qaidam Basin record erosion of the Altyn Tagh and high terrain west of that basin and presumably the concurrent growth of the northeastern Tibetan Plateau. A detailed magnetostratigraphic study of the Huatugou section, northwestern Qaidam basin, reveals that this section spans the period from similar to 30 to similar to 11 Ma. Magnetostratigraphic and sedimentological studies indicate that the accumulation rate abruptly increased near similar to 15 Ma. The acceleration in sedimentation rate suggests enhanced tectonic deformation in the Qaidam basin since similar to 15 Ma that may have begun simultaneously with accelerated deformation along the Altyn Tagh, Kunlun, and Haiyuan faults, which contributed to the growth history of the Qaidam basin and its surroundings since similar to 15 Ma. (C) 2015 Elsevier B.V. All rights reserved.