鄂尔多斯盆地白豹-姬塬地区上三叠统延长组物源分析

利用砂岩碎屑颗粒类型、重矿物组合、石英阴极发光、稀土元素分配模式以及岩相古地理格局等物源分析的方法,对鄂尔多斯盆地白豹-姬塬地区上三叠统延长组长2、长3、长4 5、长8段沉积期进行了物源分析。结果表明,姬塬、白豹地区砂体物源来源于盆地北缘古陆,为三角洲体系向南延伸部分。其中姬塬地区砂体属于盆地北缘安边三角洲组成部分,延伸方向是由北向南或北北东向南南西方向,白豹地区砂体为靖边-吴旗三角洲砂体向南延伸部分,两个三角洲延伸部分之间有叠置区。

Source analysis of Yanchang formation in Baibao-Jiyuan region, Ordos basin

e source was analyzed on member 2, member 3, member 4 and 5 sedimentary stages of Yanchang formation of upper Triassic in Baibao -Jiyuan region using such methods as sandstone clastic particle types, heavy minerals combination, cathodeluminescence feature of quartz, rare earth element distribution mode, and lith-facies palaeogeographic pattern etc. The results indicate that the source of the sand bodies in Baibao and Jiyuan region comes from the ancient land of the basin northern morgin, which is the southern extending part of delta system. The sand body system in Jiyuan region extending from north to south or from north north east to south south west is part of Anbian delta system lying in the basin northern morgin. The sand body in Baibao region is the southern extending part of Jingbian -Wuqi delta sand body. There is a superposition between the extending parts of two deltas.