Late Paleozoic Sedimentation on the Northern Margin of the North China Block: Implications for Regional Tectonics and Climate Change

摘要

The Late Paleozoic collision between the North China continental block and the Altaid are terranes of Mongolia represents one of the earliest and most fundamental tectonic events in the ongoing construction of Asia. New detrital zircon provenance data from Carboniferous-Permian nonmarine strata on the northern margin of North China imply that the northern margin of the North China block constituted a continental margin arc prior to this collision (-400-275 Ma) and that collision took place via south-directed subduction beneath North China. A significant and widespread climate change took place in North China in mid-Permian time, and is recorded by a change from Carboniferous and Lower Permian humid-climate, coal-bearing sedimentary facies to Upper Permian and Lower Triassic arid-climate redbeds. In northern North China, this climate change is accompanied by a paleocuirent reversal, which indicates the onset of uplift on the northern margin of the North China block. The temporal association of climate change and uplift suggests that aridification of North China may have been caused by a rainshadow effect from topography related to [he convergence and ultimate collision between the North China block and the Altaid arc terranes of Mongolia. Alternatively, climate change may have occurred as a result of northward drift of the North China block through arid subtropical latitudes.