陇东地区延长组细粒沉积物特征

发布时间：2018-07-04 13:33

  本文选题：细粒沉积 + 有机质类型　； 参考：《地质科技情报》2017年01期

【摘要】：在大量钻井、测井资料的基础上,采用岩心分析、地球化学测试等方法,从湖泊演化过程中水体盐度、氧化还原条件、生产力变化及地球化学特征等方面,对鄂尔多斯盆地陇东地区细粒沉积物特征、分面规律及其主控因素进行了研究,取得的主要认识有:鄂尔多斯盆地陇东地区延长组长7段沉积期,气候温暖潮湿,半深湖-深湖大面积分布,富有机质细粒沉积物发育,该期形成的富有机质页岩主要受湖盆底形、砂体沉积模式的影响。尤其长73亚段沉积期为细粒沉积物主要发育期,快速湖侵,湖水深度和范围急剧增加,湖泊表层水体与底层水体存在盐度分层,形成大面积缺氧环境,有利于大规模发育富有机质页岩。深湖区平缓地带,陆源碎屑供给不足,有机碳含量高,有机质类型好(以Ⅰ、Ⅱ型为主),半深湖区斜坡带发育物源来自于陆地的粉砂质泥岩,干酪根以Ⅱ型为主,同时发育Ⅲ型干酪根。
[Abstract]:On the basis of a large amount of drilling and logging data, core analysis, geochemical testing and other methods are used to analyze the salinity of water body, redox conditions, productivity changes and geochemical characteristics in the process of lake evolution. The characteristics of fine grained sediments in Longdong area of Ordos Basin are studied. The main results are as follows: the sedimentary period of Chang 7 in Longdong region, Ordos Basin, the climate is warm and humid. The semi-deep lacustrine and deep lake distributed in large area, and the organic matter rich shale formed in this period was mainly influenced by the lacustrine basin bottom and the sedimentary model of sand body. Especially, the deposition period of Chang73 submember is the main developing period of fine grain sediments, which is characterized by rapid lake transgression, sharp increase in depth and range of lake water, and stratification of salinity between the surface and bottom water of the lake, which forms a large area of anoxic environment. It is conducive to the large-scale development of organic shale. In the flat zone of the deep lake region, the continental clastic supply is insufficient, the organic carbon content is high, the organic matter type is good (type 鈪，

本文编号：2096236