全球白垩系烃源岩分布及沉积环境  

Global distribution and sedimentary environment of the Cretaceous source rocks

作　　者：杨静懿[1] 李江海[1] 马丽亚[1] 

机构地区：[1]造山带与地壳演化教育部重点实验室,北京大学地球与空间科学学院,北京100871

出　　处：《古地理学报》2014年第3期401-410,共10页Journal of Palaeogeography：Chinese Edition

基　　金：国家重点基础研究发展计划"973计划"项目(编号:2009CB219302)资助

摘　　要：烃源岩是油气生成的物质基础,白垩系烃源岩以29%的比例居全球各层系之首。通过古地磁与地理信息数据耦合,以及对所有白垩系烃源岩层位数据的统计和对比,恢复了白垩系烃源岩的分布特征,分析了其发育环境。结果表明:(1)白垩系烃源岩主要发育于阿普特阶—土伦阶(占白垩系烃源岩的52.63%)。(2)白垩系烃源岩主要发育于2种构造、沉积环境:陆表海环境(非典型被动陆缘)和裂谷环境。(3)白垩纪早期,烃源岩干酪根以Ⅰ型为主;白垩纪中期,烃源岩干酪根过渡为以Ⅱ型为主,Ⅰ型较少;白垩纪晚期,Ⅲ型干酪根烃源岩迅速增多。(4)白垩纪大陆裂解边缘出现富有机质沉积,上升流促进生物繁盛,高温、干旱的气候使陆表浅海区盐度较高,其还原环境有利于烃源岩的保存。Hydrocarbon source rock is the material basis of oil and gas. The Cretaceous source rocks which account for 29% of all hydrocarbon source rocks occupied the top place in all series of strata. The precise distribution and characteristics of the Cretaceous source rocks in palaeoenvironment are recovered by statistical analysis and the coupling of paleomagnetism and geographic information. The results show： （1） Cretaceous source rocks were mainly deposited in the Aptian-Turonian （nearly 52.63% of the Cretaceous source rocks） ; （2） Two types of palaeoenvironments were favorable for source rock deposition, including epeiric sea （ atypical passive margin） and rift environment; （3） The kerogen of source rocks mainly consisted of type Ⅰ in the early Cretaceous. Then type Ⅱ became the majority in the middle of Cretaceous. The proportion of type Ⅲ increased rapidly at the late Cretaceous; （4） The rich organic matter more likely appeared along the continent breakup edge with thriving plankton caused by the upwelling current. The high temperature and arid climate created high salinity areas in the shallow parts of epeiric sea which helped to preserve the source rocks.

关 键 词：白垩纪 全球烃源岩 沉积相 古环境 编图 

分 类 号：TE122.15[石油与天然气工程—油气勘探]