Detrital zircon U-Pb geochronology from the Upper Carboniferous sediments of Benxi Formation in the North China Craton: implications for tectonic-sedimentary evolution

The provenance of the Upper Carboniferous Benxi Formation in North China Craton (NCC) has been considered as the northern margin of the NCC, not the North Qinling Orogenic Belt. To understand the provenance and the tectonic-sedimentary evolution during the sedimentary period of the Benxi Formation, the zircon U-Pb geochronology analysis was conducted on eleven clastic sandstone samples. The south of the NCC received clastic sediments from the North Qinling Orogenic Belt. The orogenic movements around the NCC in the Late Carboniferous period had significant impacts on the changes in paleotopography. During the early sedimentary period of the Hutian member of the Benxi Formation, the north of the Qinling Orogenic Belt was rapidly uplifted, and paleotopography was south-uplifting and north-dipping; thus, the clastic, source was the North Qinling Orogenic Belt. From the late sedimentary period of the Benxi Formation Hutian member to the sedimentary period of the Jinci member. paleotopography was reversed. The northern margin of die NCC quickly uplifted, and paleotopography was north-uplifting and south-dipping. Two distinct provenances were present in the sediments of the Benxi Formation. The sediments were supplied predominately by the provenance in the north.