Some aspects of excellent marine source rock formation:implications on enrichment regularity of organic matter in continental margin basins  

作　　者：Wenhao Li Zhihuan Zhang Youchuan Li 

机构地区：[1]School of Geosciences, China University of Petroleum [2]Research Institute of Unconventional Petroleum and Renewable Energy, China University of Petroleum [3]State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum [4]CNOOC Research Institute

出　　处：《Chinese Journal Of Geochemistry》2015年第1期47-54,共8页中国地球化学学报

基　　金：supported by the Major State Basic Research Development Program (973 Project) (Number: 2009CB219402);Key Program of National Natural Science Foundation of China ((Number: 41330313)

摘　　要：Through the analysis of ocean organisms, the distribution characteristics and enrichment of organic matters in modern marine sediments and ancient marine strata, this paper shows that the main factors influencing the formation of excellent marine source rocks are the paleoclimate, biologic productivity, terrestrial organic matter, oxidation–reduction environment, sedimentation rate, and the type of the basin. In addition to those factors,high biologic productivity or high content of terrestrial organic matter input is a requirement for the enrichment of the organic matter in a marine environment. Reducing environment was favorable for organic matter accumulation and preservation in depositing and early diagenesis stage, which is an important element for the formation of high-quality marine source rocks. Paleoclimate also influences the marine source rocks formation, as humid subtropical and tropical climates are the most favorable regimes for the formation of marine source rocks. Wind transports some vascular plant materials into the marine environment. Furthermore, upwellings driven by steady wind can cause high biologic productivity, thus formingorganic-C-rich mud. Suitable sedimentation rate is beneficial for marine organic matter accumulation. Moreover, the type of the basin also plays an important role in the development of marine source rocks. Silled basins with a positive water balance often act as nutrient traps, thus enhancing both productivity and organic matter preservations, while in open oceans, organic matter enrichment in sediments has just been found in the oxygen minimum layers.Through the analysis of ocean organisms, the distribution characteristics and enrichment of organic matters in modern marine sediments and ancient marine strata, this paper shows that the main factors influencing the formation of excellent marine source rocks are the paleoclimate, biologic productivity, terrestrial organic matter, oxidation-reduction environment, sedimentation rate, and the type of the basin. In addition to those factors, high biologic productivity or high content of terrestrial organic matter input is a requirement for the enrichment of the organic matter in a marine environment. Reducing environment was favorable for organic matter accumula- tion and preservation in depositing and early diagenesis stage, which is an important element for the formation of high-quality marine source rocks. Paleoclimate also influ- ences the marine source rocks formation, as humid sub- tropical and tropical climates are the most favorable regimes for the formation of marine source rocks. Wind transports some vascular plant materials into the marine environment. Furthermore, upwellings driven by steady wind can cause high biologic productivity, thus forming organic-C-rich mud. Suitable sedimentation rate is benefi- cial for marine organic matter accumulation. Moreover, the type of the basin also plays an important role in the development of marine source rocks. Silled basins with a positive water balance often act as nutrient traps, thus enhancing both productivity and organic matter preserva- tions, while in open oceans, organic matter enrichment in sediments has just been found in the oxygen minimum layers.

关 键 词：海相烃源岩 大陆边缘盆地 富集规律 有机物 氧化还原环境 生物生产力 海洋沉积物 海洋生物 

分 类 号：P618.13[天文地球—矿床学]