吐哈盆地侏罗系层序地层学研究  

Sequence Stratigraphy of Jurassic in Turpan-Hami Basin

作　　者：沈守文[1] 彭大钧[2] 颜其彬[1] 黄先律[2] 李志军 

机构地区：[1]西南石油学院,四川南充637001 [2]成都理工学院,成都610059 [3]吐哈油田物探研究所,新疆哈密839000

出　　处：《沉积学报》2001年第2期263-270,共8页Acta Sedimentologica Sinica

基　　金："油气藏地质及开发工程国家重点实验室"开放基金项目!(PLN972 2)资助

摘　　要：吐哈盆地侏罗系是一个盆地充填层序 (一级层序 ) ,包括 4个构造层序 (二级层序 ) ,分别与侏罗纪湖盆的 4个演化阶段 (稳定沉降阶段、短期收缩阶段、扩张阶段和萎缩阶段 )相对应 ,其中又分为 13个 (三级 )层序。与海相地层不同的是 ,本区识别出了 4种层序边界类型 (A型、B型、C型和D型 ) ,其对应的层序本文分别称之为冲积层序、淹没层序、类Ⅰ型层序和类Ⅱ型层序。冲积层序形成于构造剧烈抬升时的盆地萎缩阶段 。Fourteen sequence boundaries showing onlap or erosional truncation are recognized in the seismic sections of the Jurassic Turpan Hami basin.The two major boundaries (at the top and bottom of the Jurassic deposits)are regional unconformities extending beyond the basin.Three intermediate ones (between 3 re and 4 th section of Xishanyao Fm.Qikeai Fm.and Sanjianfeng Fm.and Kalaza Fm.and Qigu Fm.) are unconformities spaning most of the basin.The remaining nine sequence boundaries are local unconformities.The Jurassic sedimentary strata in Turpan Hami basin is a basin fill sequence (1 st order)including four tectonic sequences(2 nd order) and thirteen depositional sequences(3 rd order).The four tectonic sequences are bound with the four evolutionary stages(stable subsidence,short time contraction,expansion,and uplift desiccation)of the lake basin. According to classic sequence stratigraphy,there are two types of sequences and sequence boundaries in passive continental margins with a shelf and slope.The types of depositional sequences in terrestrial basin,however,are not the same as those from a passive continental margin.Four types of sequence boundaries(type A,B,C,and D)are identified in the basin.A type A boundary is formed at the desiccation stage of the lake basin caused by strong tectonic uplift.The sequence above the type A boundary is here termed as fluvial sequence, in which the major systems tract is a lowstand deposit composed of alluvial fan and fluvial facies.A type B boundary,where base level falls below the previous shore slope break and then rises rapidly,occurs as the stage of basin expansion caused by rapid tectonic subsidence.The corresponding sequence without the lowstand systems tract is here termed as submerged sequence. A type C boundary,where base level also falls below the previous shore slope break and fluvial incision occurs,is similar to the type 1 boundary identified by Vail et al(1977).The lowstand systems tract with deposits of basin floor fan and i

关 键 词：层序地层 可容空间 微量元素 侏罗系 吐哈盆地 盆土 

分 类 号：P539.2[天文地球—古生物学与地层学] P534.52[天文地球—地质学]