Akademik Veri Yönetim Sistemi
Earth and Planetary Science Letters, cilt.683, 2026 (SCI-Expanded, Scopus)
The Neogene intracontinental deformation pattern in the northern Tibetan Plateau (NTP) remains a topic of active debate, particularly concerning the tectonic interplay between the large-scale strike-slip Altyn Tagh fault zone (ATF) and the Qilian Shan thrust system. To clarify the timing and mechanisms of this interaction, we conducted an integrated analysis of Neogene sediments from the Hongyazi intermontane basin, which is influenced by both the left-lateral strike-slip motion along the ATF and the northeast-directed crustal shortening associated with the Qilian Shan. A high-resolution magnetostratigraphic framework spanning 17.76–8.69 Ma was established, constrained by a calcite U-Pb age and biostratigraphic data. Lithology, gravel composition, and detrital zircon U-Pb age distributions collectively record a marked change at ∼12.4 Ma, revealing a shift in sediment provenance linked to rapid uplift of the Danghenan Shan. Notably, paleomagnetic data indicate that vertical-axis rotations of the Hongyazi Basin and other basins adjacent to the western Qilian Shan thrust belts reversed from clockwise to counterclockwise at the same time, coinciding with a progressive slowing of the rotation of basins adjacent to the western ATF. The synchronicity between this rotational reversal and accelerated deformation in the Qilian Shan signals a major tectonic reorganization across the NTP, driven by the coupled effects of ATF shearing and crustal shortening within the Qilian Shan. Thereafter, the strain-accommodating role of the ATF progressively weakened, and the India-Eurasia convergence was increasingly absorbed by broadly distributed crustal shortening across the NTP. This shift marked a fundamental tectonic transition in the Neogene northward growth of the plateau, from boundary-parallel strike-slip faulting to internally distributed, continuous deformation.