地质学报2017，Vol.91Issue(5)：1120-1129,10.
鄂尔多斯盆地西南地区延长组长7段细粒沉积物特征研究
Characteristics of Fine-Grained Sediments from the 7th Member of the Yanchang Formation in the Southwestern Ordos Basin
摘要
Abstract
Fine-grained sediments extensively occur in the southwestern Ordos Basin.Based on a volume of drilling and logging data,redox condition and geochemical features of core,this study discusses the distribution rule and major controlling factors of the fine-grained system.The results show that the 7th Member of the Yangchang Formation in the southwestern Odors basin deposited in a warm and humid condition and is extensively distributed in semi-deep or deep lacustrines,with organic fine-grained shale well developed.Organic matter-rich shale formed on the bottom of lake basin and was affected by sedimentary modes of sand body.During the deposition of the Chang 73 Member,lake water invaded rapidly,increasing depth and size of the lake.The high productivity resulted in the layering of water body (salinity) and formed extensive anoxic environment,which are conductive to development and preservation of organic matter-rich shale.In silent deep-flat lake,insufficient clastic supply and high organic carbon gave rise to type Ⅰ and type Ⅱ kerogens,while in slope semi-deep lake close to the delta front,sediments are affected by terrestrial clastics and dominated by silty mudstone,with type Ⅱ kerogen and development of type Ⅲ kerogen.关键词
细粒沉积/有机质类型/长7段/深湖—半深湖Key words
fine-grained sediment/organic-rich shale/the 7th Member of the Yangchang Formation/Ordos basin引用本文复制引用
李威,文志刚..鄂尔多斯盆地西南地区延长组长7段细粒沉积物特征研究[J].地质学报,2017,91(5):1120-1129,10.基金项目
本文为中国石油科技创新项目“中国西部典型高酸值油藏的成因机理解剖”(编号2008D-5006-01-10)资助成果. （编号2008D-5006-01-10）
