准噶尔盆地南缘油页岩特征及控矿条件

Characteristics and ore-controlling condition of oil shale in Southern margin area of Junggar Basin

准噶尔盆地南缘油页岩资源储量巨大且发现已久,详细研究该区油页岩特征和控矿条件是明确其油页岩成矿特征与成矿规律的重要基础,为进一步指导勘探与有利区预测提供理论支撑。通过野外地质调查和地球化学实验分析等方法相结合,认为准噶尔盆地南缘2个油页岩群分别发育于中二叠统芦草沟组一、二段,以位于一段下亚段第一油页岩群的工业意义最大;油页岩以低品级为主,体积分数达77.19%,属于高灰分油页岩;滨浅湖和深湖形成的油页岩类型以深灰-棕灰色泥岩与夹白云岩薄层的页岩为主,泥灰岩次之且常与灰质粉砂岩或灰岩呈伴生关系,物缘区母岩类型是控制油页岩化学成分的重要因素之一;火山事件对油页岩区物源的控制大于其对成矿终止的控制。

The huge reserves of oil shale is detected long time ago at the southern margin of Junngar Basin. Carefully researching the characteristics and ore-controlling condition of oil shale in the southern margin of Junggar Basin mainly is great foundation to specifying the forming characteristics and formation law of oil shale deposit,and also provides theoretical reasons to the further guiding exploration and prediction of favorable areas. Based on field geological investigation,petrology and geochemistry study that two oil shale groups in Junggar basin were developed in Member 1,2 of the Junggar Formation of middle Permian series,the first oil shale group located in Lower-1 st member have the greatest industrial significance. Oil shale always has the accompanying relationship with overlying limy siltstone or limestone. The oil shale ore of this area have four types,including pure mudstone,marlston and mudstone both with banded silty stone and lends,and shale of dolomicrite sandwich,and the main types are mudstone and shale. The recoverable oil shale composed of 77. 19% low-grade and they are high-ash oil shale. The type of oil shale ore from shore shallow-deep lake environment is dark-brown grey mudstone and mudstone with thin dolomicrite. Mother rock types of provenance is one of the most important factors to explain the characteristics of chemical composition. The volcanic event which controlled the provenance in the area of oil shale is outweigh the begging and ending of the mineralization of the oil shale.