Provenance analysis of the late Mesoproterozoic to Neoproterozoic Xuhuai Basin in the southeast North China Craton: Implications for paleogeographic reconstruction

Abstract

The late Mesoproterozoic to Neoproterozoic sedimentary rocks in the southeast North China Craton (NCC) are significant in paleogeographic reconstruction. An integrated approach of field investigation, detrital zircon U-Pb dating, and Lu-Hf isotope analysis reveals essential information on the tectonic-sedimentary evolution of the Xuhuai Basin. New age constraints show that the Xuhuai Basin comprises a lower (Huaihe Group, 1.1–0.9 Ga) and an upper (Langan Group, <0.82 Ga) successions, with an unconformity between them. The depositional age of the middle to upper part of the Huaihe Group (the Niyuan-Wangshan formations) is limited to 0.97–0.89 Ga. A comparison of regional basin formations suggests that the Xuhuai, Jiaolai, Dalian, and Pyongnam basins belong to the same rift system (the Xuhuai rift system). There was a distinct provenance change from ~2.7–2.5 Ga, ~2.1 Ga and ~1.9 Ga rocks (zircon ages) in the lower part, to 1.8–1.0 Ga in the middle-upper part of the Huaihe Group, and back to ~2.7–2.5 Ga, ~2.1 Ga and ~1.9 Ga rocks in the Langan Group. The ~2.7–2.5 Ga, ~2.1 Ga, ~1.9Ga, and ~1.8–1.4 Ga provenances could be from the NCC, while the 1.2–1.0 Ga provenances were possibly from the Grenvillian orogens which could be far or close neighbors of the NCC before 0.9 Ga. While both the 1.4–1.3 Ga and 1.2–1.0 Ga provenances possibly support a North China-São Francisco-Congo connection hypothesis, in which the Early Neoproterozoic basins such as the Xuhuai rift basins along the southeastern margin of the NCC, the coeval basins along the eastern and western margins of the São Francisco Craton and the west Congo Craton comprise a correlated rift system during 1.1–0.9 Ga.