Provenance Analysis and Dating of Parent Rocks of the Sandstones  from Kepingtage Formation(Silurian) in the Northern Tarim Basin

Key words: 
• northern Tarim Basin /
• Kepingtage Formation /
• provenance analysis /
• SHRIMP UPb ages of detrital zircons

Abstract:  According to the observation of petrographic thin sections, the approaches of the heavy mineralogy analysis and the analysis of SHRIMP UPb ages of detrital zircons, which is of the sandstone samples taken from the Dawangou outcrops of Keping area and the drill cores of TP3,TP7 and KQ1 in northern Tarim Basin, as well as using the classic Dickinson Ternary Diagram method and combining with regional geology background analysis, we make a conclusion that the provenance of the sandstones in the Kepingtage Formation of Silurian in the west area of northern Tarim Basin is different from that in the center and east area of northern Tarim Basin. The tectonic setting of the former provenance is the continental island arc environment, and it is composed of the materials from the Proterozoic upper crust. Thus the provenance is inferred to be Tabei uplift. However, the tectonic setting of the latter provenance is the recycled orogens environment and it is composed of the Ordovician materials. So, the provenance is inferred to be Kuluketage uplift. The type of provenance is widely igneous rock. Compared with the center and east area of northern Tarim Basin, the west area is farther to the provenance. These conclusions are of great importance to the reconstruction of paleogeography deposition environment and the analysis of the type and evolution of Tarim Basin.