地质学报2017，Vol.91Issue(3)：617-628,12.
湖泊深水重力流沉积露头精细解剖——以鄂尔多斯盆地瑶曲剖面长7油层组为例
Outcrop-Based Analysis of a Deep-Water Gravity Flow Sediments in Lake:A Case Study from the Chang 7 of Yaoqu Section, Ordos Basin
摘要
Abstract
Outcrop-based sedimentary section plays an irreplaceable role in detailed analysis for internal architecture of sedimentary bodies and building accurate underground geological model.Taking the Chang 7 oil layer of Yaoqu Section developed in the south of Ordos Basin as an example,we discusses the type,characteristics,vertical sequences and sedimentary environment of deep-water gravity flow deposits of deep-water lithofacies employing geology,field outcrops and sedimentology.It is suggested by this study that six lithofacies including massive fine silt facies,Bouma Sequence siltstone facies,horizontal lamination bedding mudstone facies,massive mudstone facies and tuff facies,and five kinds of sedimentary units including debris flow deposit,turbidite deposit,slump deposit,deep-water original deposit and tephra deposit have occurred in Chang 7.Five kinds of sedimentary units constitute the distribution of A,B,C and D in vertical direction.In combination with the regional geological features,our study suggests that the sedimentary system developed in Chang 7 include mainly lake and channel gravity flow deposit.Lacustrine facies can be further divided into shore-shallow lake facies,deep-water in-situ sedimentary microfacies,with D type as the most developed lithofacies association.Channel gravity flow deposit can be further divided into four subphases,such as near source channel,far source channel,embankment and front lobe bodies,including three micro phases such as sandy debris flow deposit,turbidite deposit and slump deposit.Near source channel + embankment formed lithofacies associations of class A,class C and class B,and far source channel + embankment formed lithofacies associations of class B and class C,and front lobe developed into class C lithofacies association.The profile phase analysis shows that the topquality hydrocarbon rocks and gravity flow sandbody in the study area could form favorable tight lithological oil and gas reservoir with "lower-generation and upper storage".关键词
沉积露头/岩相类型/垂向组合/湖泊深水重力流/长7段/鄂尔多斯盆地Key words
outcrop-based/lithofacies type/vertical combination/deep-water gravity current of lake/Chang 7 oil layer/Ordos Basin引用本文复制引用
吕奇奇,罗顺社,付金华,向吉,牛小兵,龚辰,徐黎明,冯胜斌,李士祥..湖泊深水重力流沉积露头精细解剖——以鄂尔多斯盆地瑶曲剖面长7油层组为例[J].地质学报,2017,91(3):617-628,12.基金项目
本文为国家自然科学基金项目(编号41672099)和国家重点基础研究发展计划“973”项目(编号2014CB239003)联合资助成果. （编号41672099）
