The late Paleozoic lithofacies paleogeography and tectonic-sedimentary evolution of the eastern South China

Key words: 
• South China /
• Late Paleozoic /
• Strata isopach maps /
• Lithofacies maps /
• Basin subsidence

Abstract: [Objectives] After the early Paleozoic Wuyi-Yunkai orogeny, the eastern South China went into a tectonic quiescence period during the late Paleozoic, with large-scale marine transgression and think sedimentary strata accumulation. Specifically, nature of the lower Devonian to lower Permian (the Kungurian stage) strata, such as isopach change of strata, lateral variation of lithofacies, are important to understand the post-orogenic topography of the eastern South China. [Methods] We collected stratigraphic thicknesses and lithological data of the lower Devonian to lower Permian (the Kungurian stage) strata in the eastern South China, compiled strata isopach maps and lithofacies maps of six main stages, including the early Devonian, the middle Devonian, the late Devonian, the early Carboniferous, the late Carboniferous to early Permian (the Sakmarian stage), and the early Permian (the Artinskian and Kungurian stages). The tectonic subsidence rate of the basin at five different localities in each stage was calculated. [Results] The results show that the subsidence of the late Paleozoic basin of the eastern South China can be divided into two stages. The first stage was the Devonian with a high subsidence rate (about 25 m/Ma). The second stage was the Carboniferous to early Permian (the Kungurian stage) with a low subsidence rate (about 10 m/Ma). [Conclusions] Taking the regional widely-distributed and large-scaled normal faults into consideration, it speculates that the first stage of basin subsidence was mainly controlled by tectonic activities, which was inherited from the post-Wuyi-Yunkai orogenic collapse and possibly the drifting-away of South China from the Gondwana during the Devonian. The second stage of basin subsidence was controlled by the icehouse climate and sediment load of the baisn during the Carboniferous to early Permian.