【摘要】 准噶尔盆地西北缘前陆冲断带是剖析西准噶尔地区盆山耦合关系、沉积体系发育的关键地段。该区二叠系佳木河组为火山岩、火山碎屑岩、碎屑岩组成的混积地层。火山岩与碎屑岩组成的地层单元有广义上的成因联系,因为它们都属于史密斯地层,并均具有旋回特征。针对不同的岩性区:碎屑岩岩性区、火山岩与碎屑岩共存区、纯火山岩区,找出由于构造火山活动、相对湖平面变化等因素形成的可作为层序界面的不整合面。碎屑岩岩性区不整合面在地震剖面上主要表现为削蚀、底超、双向下超、顶超、下切谷等;共存区为同时发育火山岩与碎屑岩的削蚀带,不整合面类型较复杂;纯火山岩区表现为相对湖平面下降形成的削蚀不整合面。故可以通过地震、钻测井资料识别各类不整合面,并依据火山喷发方式、火山旋回、沉积旋回,按照不同对比原则进行经典层序地层学划分。更多还原

【Abstract】 The foreland thrust belt in northwestern margin of the Junggar Basin is a significant region to research basin-range coupling and development of sedimentary system of western area of Junggar Basin.Jiamuhe Formation in Permian is mixing accumulated formation which contains volcanics,volcanoclastic and clastic rocks.Volcanics stratigraphic unit and clastic rock stratigraphic unit have the generalized origin relation,which are Smith formation and with cycles.According to the difference of lithologic character,there are clastic rock area,volcanics and clastic rock mixed area and volcanics area.In different areas,we apply different ways to find some types of unconformity surfaces generated by tectogenesis,volcanic activity or fluctuation of lake-level and used as sequence boundaries.In clastic rocks area,unconformity surfaces in seismic profiles are represented as a truncation,a baselap,a bidirectional downlap,a toplap or an incised valley;In the mixed area,a truncation belt;while in the volcanics area,a truncation formed by relatively falling of lake-level.So we can identify different unconformity surfaces by seismic,drilling and log data,and then divide sequences in different sedimentary environments by correlation rules based on volcanic eruption types,volcanic cycle features and sedimentary cycle features.更多还原