Tectonic–paleogeographic evolution of the Late Triassic in the Sichuan basin, SW China: Constraints from sedimentary facies and provenance analysis of the Xujiahe Formation

Abstract

Late Triassic sedimentary successions in the Sichuan Basin contain records about the transition from marine to continental environments. In this study, we focused on the field profile of the Xujiahe Formation to analyze its sedimentary distribution and provenance by using petrological, sedimentary facies, geochemistry, and provenance analyses. The results have shown that the Upper Triassic Xujiahe Formation in the Guangyuan area consists of marine and continental clastic materials. The potential source areas for these sediments include the Qinling orogenic belt, Longmen Mountain structural belt, and Motianling ancient land. The tectonic setting of the Sichuan Basin during this period could be attributed to an active continental margin.