鄂尔多斯盆地埋藏演化史恢复

鄂尔多斯盆地沉积背景和勘探资料表明,盆地西部地区白垩系的声波时差资料具有明显的分段性,用泥岩压实趋势法估算三叠系及其以上地层剥蚀厚度缺乏普遍适用性.采用钻井分层资料“点连线、线线相交闭合”方式及以地层对比为主的方法对三叠纪以来4期地层抬升并遭受剥蚀的剥蚀量进行了恢复,并对结果进行了对比验证.恢复结果表明,白垩纪末期为三叠纪以来最强烈的一期全盆抬升剥蚀事件,三叠纪末期、中侏罗世和侏罗纪末期这3期剥蚀事件相对较弱.自三叠纪以来,盆地表现出掀斜构造演化过程.

Restoration of burial history of four periods in Ordos Basin

The sedimentary background and exploration data show that the interval transit time curves of the Cretaceous in the western Ordos Basin are made up of several subsections. The mudstone compaction curve method is unsuitable to calculate the erosion thickness of the Triassic and post-Triassic strata. The correlation of strata was used to calculate the erosion thickness of the Triassic, Middle Jurassic, Later Jurassic and Later Cretaceous periods. The restored results are calibrated with the method of section ties and compared with the results of early research. The restoration results indicate that the strongest uplift erosion event among the four events took place in the Later Cretaceous. The restored results of burial history show that the basin has experienced tilted structural evolution from west to south to southeast to east since the Mesozoic.