Detrital provenance of Early Mesozoic basins in the Jiangnan domain, South China: Paleogeographic and geodynamic implications

Abstract

Detrital provenance analysis is an effective way to understand paleogeographic change and geodynamics. In this paper, we present petrological, whole-rock geochemical and detrital zircon U–Pb geochronological analysis of Early and Middle Jurassic terrestrial clastic rocks in the Jingdezhen Basin and the Huangshan Basin in the Jiangnan domain, South China. Petrology and whole-rock geochemistry show that the source rocks are dominated by intermediate to acid component. The Chemical Index of Alteration ranges from 69 to 86, suggesting a moderate weathering history for the source rocks. The Early–Middle Jurassic sediments in the Jingdezhen and Huangshan basins were mostly sourced from magmatogenic greywackes and felsic magmatic rocks, respectively. Detrital zircons have seven age peaks at ~240Ma, ~430Ma, ~1390Ma, ~1880Ma, ~2500Ma, –3200Ma and 788–999Ma (a wide peak). Provenance analysis indicates that the source rocks are in the Jiangnan domain, the Northwest Zhejiang Basin and the Wuyishan domain. Combining these with previous results and paleocurrent directions, we infer that the NE-trending Wuyishan and Xuefengshan domains and the nearly E–W-Jiangnan domain and Nanling tectonic belt were orogenic uplifts and watersheds during the Late Triassic to Middle Jurassic. The Early Mesozoic geodynamics in the South China Block was related to the westward subduction of the Paleo-Pacific Plate and the northward continent–continent collision following the closure of the Paleo-Tethys Ocean.