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

• DOI: 10.1130/l1037.1
• Publication Date: 2018-12-21T16:30:41Z
• Authors: Haijian Lu; Jiacan Ye; Licheng Guo; Jiawei Pan; Shangfa Xiong; Haibing Li
• Keywords: Paleocurrent; Basement; Geochronology

Determining the provenance of sedimentary basin fill in northern Qaidam Basin is a key step toward understanding system dynamics and mountain-building processes surrounding orogenic belts Tibet. The exceptionally thick (average 6–8 km) Cenozoic fluvio-lacustrine deposits were once thought to have been eroded from nearby margin southern Qilian Shan reflect prolonged thrust-related exhumation these belts. However, several recent studies, based mainly on paleocurrent detrital zircon U-Pb age data, suggested that they derived distant East Kunlun south, or Qimen Tagh southwest (at least 200 350 km Basin, respectively). That model assumed formed significant topographic barriers during earliest sedimentation strata (e.g., Lulehe Formation) Basin. Therefore, tectonic significance Formation remains fundamental problem postcollisional uplift history Tibetan Plateau. To address this issue, we conducted sedimentological analyses dating Mesozoic results, combination with existing seismic reflection collectively indicate although source area cannot be specified by matching ages rocks crystalline basement rocks, other evidence points consistently unified proximal northerly (the Shan). Our results emphasize noncrystalline rocks) fold-and-thrust should taken into consideration when seeking potential areas correlating siliciclastic detritus related rocks. In addition, study strongly supports claim variations proportions populations used caution determining terrane comparisons distributions.