鄂尔多斯盆地合水地区延长组—延安组地层分布特征  

THE DISTRIBUTION FEATURES OF THE YANCHANG AND YAN'AN FORMATIONS IN HESHUI AREA,ORDOS BASIN

作　　者：陈永峤[1] 李伟华[1] 汪凌霞[1] 文志刚[1] 

机构地区：[1]长江大学地球化学系油气资源与勘探技术教育部重点实验室,湖北荆州434023

出　　处：《地层学杂志》2011年第1期41-48,共8页Journal of Stratigraphy

基　　金："西峰两侧地区长3以上石油富集区筛选"项目支持

摘　　要：利用岩芯、测井等资料,研究了鄂尔多斯盆地合水地区延安组的煤层或炭质泥岩、侏罗系与三叠系之间的不整合面以及延长组的凝灰岩、凝灰质泥岩或泥岩等不同类型的标志层特征,并利用这些标志层对地层进行了油组划分和对比,重点分析了延长组2段—延安组10段各油组地层的分布特征:三叠纪延长组上部地层受到了不同程度的剥蚀,西南部的地层缺失较东北部严重,年代越新的地层缺失得越多,其中长1地层缺失最为严重,其次是长2地层,依次是长3、长4+5、长6地层,且仅在古河道中才缺失,而长7地层基本没有受到剥蚀;富县组分布局限且厚度变化大;延安组的延10地层仅分布在子午岭高地以西的地区,古河道内地层厚度较大,延9地层的沉积处在填平补齐时期。Based on well cores and logging data, the features of marker beds ,such as coal beds or bass of Yan＇an Formation, unconformity surface between Jurassic and Triassic, tuff or tuffaceous mudstone or mudstone of Yanchang Formation in Heshui of the Ordos Basin are studied in the paper. Then, the oil bed strata of the study area is divided and correlated using those marker beds, and distribution features of strata from the 2nd menber of Yanchang Formation to the 10th menber of Yanan Formation are analysed mainly. It is concluded that strata in the top of Yan＇an Formation had subjected to denude on varying extent, consequently, stratigraphic loss of south-west is more sever than that of north-east, and the older the more complete stratigraphic, thereinto, the loss of Chang 1 and Chang 2 strata is the most, Chang 3 and Chang 4＋5 strata is only lost in ancient rive, Chang 6 and Chang 7 strata is integrity. Fuxian Formation strata has a varying thickness and limited distribution in the lower Yan＇an Formation, Yan 10 strata is distributed instably, thicker in ancient river and thinner in both sides, and is not deposited on the highlands.

关 键 词：标志层 地层划分和对比 延长组 富县组 延安组 侏罗系 三叠系 鄂尔多斯盆地 

分 类 号：P534.51[天文地球—古生物学与地层学] P534.52[天文地球—地质学]