Paleoxygenation facies and oxygendeficient environmental model of the Devonian source rocks from southern South China Sea：
An example from the Middle and Upper Devonian of Guangxi
DU Yuan-Sheng, GONG Yi-Ming, ZHANG Zhe, ZENG Xiong-Wei
1 Key Laboratory of Biogeology and Environmental Geology of Ministry of Education， Wuhan430074， Hubei
2 China University of Geosciences(Wuhan)， Wuhan430074， Hubei
xygendeficient environment is an important condition for formation and preservation of marine source rocks. The study of paleoxygenation facies is significant for tracing spatialtemporal distribution of highquality marine source rocks and interpreting the evolution of depositional environments. During the Devonian， carbonate platform(nearshore and isolated platforms)and inner platform taphrogenic trough resulting from intracontinental rifting were simultaneously developed in the southern South China Sea. The Devonian paleoxygenation facies types are controlled by seawater layering in platform troughs and the QinzhouFangcheng taphrogenic trough， where quasianaerobic and anaerobic facies were dominant. The paleoxygenation facies is controlled by sealevel changes in platform in which developed aerobic and dysaerobic facies. Siliceous， phosphorus and organic carbonrich deposits of the Devonian indicate the upwelling flows influence. The southern South China Sea was located in the tradewind zone near the equator in the Devonian. Westward surface ocean current passed over the southern South China Sea and formed offshore currents. Eastward bottom current compensated toward shore and formed the upwelling flow. The Devonian upwelling flow led to the formation of an oxygendeficient environment in the southern South China Sea.
DU Yuan-Sheng,GONG Yi-Ming,ZHANG Zhe et al. Paleoxygenation facies and oxygendeficient environmental model of the Devonian source rocks from southern South China Sea：
An example from the Middle and Upper Devonian of Guangxi[J]. JOPC, 2009, 11(1): 28-36.
