论吐哈盆地台北凹陷西部双层结构

吐哈盆地台北凹陷侏罗系到第三系盆地结构类型，究竟是属于断陷型盆地还是坳陷型盆地，长期以来都存在着不同的观点。为此，通过进行台北凹陷西部区域地层对比和地震剖面层序地层划分，分析了该区的构造演化与沉积演化，开展了沉积体系划分和沉积相带展布研究。结果认为：该地区侏罗系到第三系存在着双层结构，即在侏罗纪属于坳陷盆地，发育大型三角洲和滨浅湖及深湖、半深湖沉积；而在白垩纪和第三纪则属于山前断陷型盆地，南北短轴方向上发育山麓洪积扇体系。这一结论为理清该区侏罗纪到第三纪沉积构造演化及盆地类型提供了一个新的思路，为该区储层综合评价及有利岩性油气藏分布区预测提供了理论依据。

DOUBLE LAYER STRUCTURE OF WESTERN TAIBEI SAG, TURPAN HAMI BASIN

There has long been a controversy over the basin structure type of the Jurassic to Tertiary in Taibei sag, the Turpan Hami Basin, i.e., being actually a faulted basin or a down warped basin. The structural and depositional evolution of the study area is analyzed, the sedimentary systems are divided, and the distribution of sedimentary facies belts is studied through stratigraphic correlation and sequence stratigraphic division on seismic section. The study reveals a double layer structure in the Jurassic to Tertiary basin of the study area, i.e. it was a down warped basin in the Jurassic when deposits of large delta, shoal shallow lake, deep lake, and semi deep lake facies were developed, while it was a piedmont faulted basin in the Cretaceous and Tertiary when piedmont alluvial fans were developed along its NS trending short axis. This understanding provides a new concept for studying the sedimentary structural evolution and basin types from the Jurassic to Tertiary, and a theoretical basis for comprehensive evaluation of reservoirs and prediction of favorable lithologic reservoirs in the study area.