Main factors controlling the deposition of the Middle-Upper Permian source rocks in Laibin area and its tectonic setting
Qiu Zhen1,2, Wang Qingchen1
1. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029;
2. PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083
Based on analyzing geochemical indicators, such as total organic concentration (TOC), paleoproductivity (Ba/Al ratio), and paleoredox (V/Cr, V/(V+Ni)), of the Maokou Formation (the Middle Permian) and the Heshan Fromation (the Upper Permian) from the Penglaitan section and Tieqiao section in Laibin area , it is concluded that (1) good source rocks (average TOC≈3%) locally developed at the Penglaitan section and (2) the basin environment with anoxic depositional condition mainly controlled the accumulation of them. Compared with regional study, we consider that source rocks not developed regionally in the Qiangui basin during the Late Permian, which was probably related to the regional uplift caused by the Emeishan Plume.