Sedimentary environment and the controlling factors of organic-rich rocks in the Lucaogou Formation of the Jimusar Sag, Junggar Basin, NW China
投稿时间:2018-01-24  
英文关键词:Organic-rich rocks, Paleoenvironment, Lucaogou Formation, Jimusar Sag, Junggar Basin
基金项目:This study was supported by the National Science and Technology Major Program of China (Grant No. 2017ZX05009002); the National Basic Research Program of China (Grant No. 2014CB239002); the Natural Science Foundation of Shandong Province, China (Grant No. ZR2014DQ016), and the Natural Science Foundation Joint Special of Shandong Province, China (Grant No. ZR2016DL05).
作者单位
Chang-Sheng Qu School of Geosciences, China University of Petroleum, Qingdao 266580, Shandong, China
Shandong University of Science and Technology, Qingdao 266590, Shandong, China 
Long-Wei Qiu School of Geosciences, China University of Petroleum, Qingdao 266580, Shandong, China
Key Laboratory of Deep Oil and Gas Geology and Geophysics, (China University of Petroleum), Ministry of Education, Qingdao 266580, Shandong, China 
Ying-Chang Cao School of Geosciences, China University of Petroleum, Qingdao 266580, Shandong, China
Key Laboratory of Deep Oil and Gas Geology and Geophysics, (China University of Petroleum), Ministry of Education, Qingdao 266580, Shandong, China 
Yong-Qiang Yang School of Geosciences, China University of Petroleum, Qingdao 266580, Shandong, China
Key Laboratory of Deep Oil and Gas Geology and Geophysics, (China University of Petroleum), Ministry of Education, Qingdao 266580, Shandong, China 
Kuan-Hong Yu School of Geosciences, China University of Petroleum, Qingdao 266580, Shandong, China
Key Laboratory of Deep Oil and Gas Geology and Geophysics, (China University of Petroleum), Ministry of Education, Qingdao 266580, Shandong, China 
摘要点击次数: 23
全文下载次数: 27
      
英文摘要:
      The Lucaogou Formation in the Jimusar Sag of the eastern Junggar Basin is an important sedimentary stratum accumulating huge amounts of lacustrine tight oil in China, where organic-rich rocks are commonly observed. Focusing on the Lucaogou Formation, a precise analysis of the inorganic and organic petrology and the inorganic geochemistry characteristics was conducted. The paleoclimate and paleoenvironment during sedimentation of the Lucaogou Formation were established, and the key factors that were controlling the accumulation of organic matter during this time were identified. The results of this study suggest that during the sedimentation of the Lucaogou Formation, the paleoclimate periodically changed from a humid environment to an arid environment. As a result, the salinity of the water and the redox environment fluctuated. During the sedimentation period, the lake showed sufficient nutrient supplies and a high primary productivity. The interval studies in the Lucaogou Formation were divided into five sedimentary cycles, where the first, second, and fifth sedimentary cycles consisted of cyclical paleoclimate fluctuations varied from a humid environment to an arid environment and shifted back to a humid environment with levels of salinity from low to high and decreased again. The third and fourth cycles have cyclical fluctuations from a humid to an arid environment and corresponding salinity variation between low and high levels. During the period when organic-rich rocks in the Lucaogou Formation deposited in the Jimusar Sag, the paleoclimate and the water body were suitable for lower aquatic organisms to flourish. As a result, its paleoproductivity was high, especially during the early period of each cycle. A quiet deep water body is likely to form an anoxic environment at the bottom and is also good for accumulation and preservation of organisms. Fine-grained sediments were accumulated at a low deposition rate, with a low dilution of organic matter. Therefore, high paleoproductivity provided a sufficient volume of organisms in the studied area in a quiet deep water body with an anoxic environment and these were the key factors controlling formation of organic-rich rocks.
Chang-Sheng Qu,Long-Wei Qiu,Ying-Chang Cao,Yong-Qiang Yang,Kuan-Hong Yu,2019.Sedimentary environment and the controlling factors of organic-rich rocks in the Lucaogou Formation of the Jimusar Sag, Junggar Basin, NW China.Petroleum Science,16(4):763~775.
查看全文  查看/发表评论  下载PDF阅读器