鄂尔多斯盆地基底断裂与能源矿产成藏成矿的关系

RELATION BETWEEN BASEMENT FRACTURES AND FORMATION OF ENERGY RESOURCES IN ORDOS BASIN

对鄂尔多斯盆地内基底断裂特征及其活动性、盆地元素地球化学场以及与能源矿产关系作了对比和分析。结果表明,鄂尔多斯盆内基底断裂控制了多种能源矿产的分布特征,盆地北部以天然气、大中型煤田为主,南部以油田、中小型煤矿为主,断裂带发育地段以油-气混合区为主,铀矿富集受基底断裂或深断裂的控制。元素地球化学场与基底断裂关系密切,不同高、低背景的元素地球化学场展布位置、走向或扭曲变形与相应地段的基底断裂存在有关,基底断裂控制了地球化学场和元素组合特征;基底断裂的存在与活动、地球化学场特征反映出盆地内存在深部流体活动的迹象,基底断裂的活动为深部流体的运移并参与多种能源矿产的成藏成矿作用提供了有利条件。

The basement fractures and their activities, element geochemistry fields, and the relationship between the element geochemistry fields and the energy resources in Ordos Basin were compared and analyzed in this paper. The results indicate that the basement fractures controlled the distribution features of multi - energy resources, most natural gas and large - to medium -scale coalfields in North Ordos Basin, and most oil fields and medium - to small - scale coalfields in South Ordos Basin. Distribution of fault zones mostly occur in the mixed regions with both natural gas and oil fields. On the other hand, the enrichment of uranium deposits in the study area is controlled by the basement or deep fractures, where element geochemistry fields are closely correlated with basement fractures. The distribution features, strikes and tortuosities of all kinds of element geochemistry fields are related with the basement fractures in the corresponding section, the geochemistry fields and its element combinations are controlled by the basement fractures. Active indication of deep fluids is reflected by the existence and the activities of the basement fractures, and the features of basement fractures and the activities of the basement fractures offer pathways for migration of deep fluids and joint formation of multi - energy resources.