鄂尔多斯盆地神木地区上古生界山西组物源分析

Analysis of the Material Source of Upper Paleozoic Shanxi Formation in Shenmu Region of Ordos Basin

随着鄂尔多斯盆地神木地区山西组新的含气富集区的发现,其物源也引起了关注与重视。应用砂岩类型、岩屑类型、重矿物组合的分布特征、阴极发光及稀土元素对比分析等方法,分析了神木地区山西组的物源问题。结果表明神木地区山西组的物源主要来自盆地北部前寒武系变质岩,重矿物组合反映了山西组物源由2条水系控制,研究区内中西部水系来自于同一源区,而东部水系来自不同的源区,但是东西源区之间具有一定的亲缘性。山西组物源方向的确定对研究区内山西组沉积相研究以及指导该地区天然气勘探有重要的意义。

Because of the discovery of a new gas concentration district in the Shanxi Formation in the Shenmu area, the special attention has been paid to the material sources of these reservoirs. The material source of the Shanxi Formation is analyzed using the sand types, cutting types in combination with the distribution characteristics of heavy minerals, cathodoluminescence and the comparison analysis of rare earth elements. The results show that the debris materials of the Shanxi Formation mainly are derived from Pre-Cambrian metamorphic rock from the north part of the Ordos basin, two water systems control the material source of the Shanxi Formation, the middle-west water systems in the research area have the same source, the east water system has another source, but they are affinitive. The material source direction of the Shanxi Formation is important for the further study of the Shanxi Formation and gas exploration.