Magnetostratigraphic and paleoenvironmental records for a LaT_e Cenozoic sedimentary sequence drilled from Lop Nor in the easT_ern Tarim Basin

摘要

The Tarim Basin, one of the largest inland basins in the world, is situated in the northwestern China and to the north of the Tibetan Plateau. Continuous Cenozoic deposits have accumulated in this basin, which are crucial for investigating the growth of the Tibetan Plateau and the paleoclimatic evolution in Asian interior. Here we report the magnetostratigraphic and paleoenvironmental records for a Late Cenozoic sedimentary sequence drilled from Lop Nor in the eastern Tarim Basin. Magnetostratigraphic results show that this core has recorded a magnetic polarity sequence from C3Bn to C1n, covering an age range from ca. 7 Ma to the present Decreased magnetic susceptibility occurred after ca. 5.6-5.1 Ma, which was interpreted to indicate an enhancement of aridity in the Tarim Basin since this period. We attribute this aridification to the combined effect of global climate cooling and the uplift of the Northern Tibetan Plateau since the late Miocene.