Towards a clarification of the provenance of Cenozoic sediments in the northern Qaidam Basin

作者：Haijian Lu, Jiacan Ye, Licheng Guo, Jiawei Pan, Shangfa Xiong, Haibing Li · 发表于：Lithosphere · 年份：2018 · DOI：10.1130/l1037.1 · 被引用次数：49 · 研究领域：Geological and Geochemical Analysis、earthquake and tectonic studies、High-pressure geophysics and materials

Determining the provenance of sedimentary basin fill in the northern Qaidam Basin is a key step toward understanding the sedimentary system dynamics and mountain-building processes of the surrounding orogenic belts in Tibet. The exceptionally thick (average of 6–8 km) Cenozoic fluvio-lacustrine deposits in the northern Qaidam Basin were once thought to have been eroded from the nearby northern Qaidam Basin margin and the southern Qilian Shan and to reflect the prolonged thrust-related exhumation of these orogenic belts. However, several recent studies, based mainly on paleocurrent and detrital zircon U-Pb age data, suggested that they were derived from the distant East Kunlun Shan to the south, or the Qimen Tagh to the southwest (at least 200 and 350 km from the northern Qaidam Basin, respectively). That model assumed that the East Kunlun Shan and Qimen Tagh formed significant topographic barriers during the earliest sedimentation of Cenozoic strata (e.g., the Lulehe Formation) in the northern Qaidam Basin. Therefore, the tectonic significance of the provenance of the Lulehe Formation remains a fundamental problem in understanding the postcollisional uplift history of the northern Tibetan Plateau. To address this issue, we conducted sedimentological and paleocurrent analyses of the Lulehe Formation and detrital zircon U-Pb dating of Mesozoic strata in the northern Qaidam Basin. The results, in combination with existing paleocurrent and seismic reflection data, collectively in...