坳陷型湖盆缓坡边缘沉积坡折带的识别--以鄂尔多斯盆地三叠纪延长期沉积坡折带为例  

Identification of Sedimentary Slope Breaks in the Margin of a Down Warped Lake Basin's Ramp Belt:A Case from Triassic Yanchang Formation,Ordos Basin

作　　者：李树同[1] 王多云[2] 王彬[1] 陶辉飞[1] 刘志伟[3] 

机构地区：[1]中国科学院地质与地球物理研究所兰州油气资源研究中心 [2]北京师范大学资源学院,北京100875 [3]中国石油长庆油田分公司工程技术管理部,陕西西安710021

出　　处：《天然气地球科学》2008年第1期83-88,共6页Natural Gas Geoscience

摘　　要：鄂尔多斯盆地中生界是典型的稳定克拉通内坳陷型湖盆沉积,在三叠纪延长期湖盆的缓坡边缘(吴旗—子午岭一线以北地区)发育沉积坡折带,利用地震反射特征及岩性地层学对比等常规手段难以对其识别。在延长组三级层序地层格架内,分别从层序地层充填形态、沉积微相组合类型、短期基准面旋回叠加类型及其相应可容空间(A)和沉积物供给通量(S)之间的比值(A/S)关系等3个方面对湖盆缓坡边缘的沉积坡折带进行了识别,在此基础上总结和归纳出了坳陷型湖盆缓坡边缘沉积坡折带的判识方法,并建立了识别模式。In Mesozoic, the Ordos basin is a down warped lake basin sediment in a typical stable Craton. In the Triassic Yanchang period, the margin of the lake basin ramp belt （northern of the line Wuqi-Ziwuling） developed sedimentary slope breaks, however, using seismic reflection characteristics and lithological stratum correlation techniques are difficult to identify it. Within a three-sequence-stratigraphic framework, this paper identifies the margin of the ramp belt＇s sedimentary slope breaks of the Yanchang period＇s basin from three aspects： sequence stratigraphy filling shape, sedimentary microfacies association types, shortterm base-level cycle superposition types, and the corresponding ratio （A / S） of the accommodation space （A） and the supply of sediment flux （S）. On this basis, an identification method of the margin of the ramp belt＇s sedimentary slope breaks of down warped lake basins and its recognition model are established.

关 键 词：鄂尔多斯盆地 层序地层 坡折带 微相组合 可容空间 

分 类 号：TE122[石油与天然气工程—油气勘探]