【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。更多还原

【Abstract】 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,short-term 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.更多还原