鄂尔多斯盆地上三叠统瓦窑堡组层序-古地理及聚煤规律
发布时间：2018-11-09 12:21
【摘要】：依据钻孔岩芯及测井曲线资料对鄂尔多斯盆地东部晚三叠世瓦窑堡组沉积相、聚煤模式、层序地层格架、岩相古地理进行研究,提出该区聚煤规律。瓦窑堡组依据岩性共分为五段,其中底部的第1段和顶部的第5段以泥岩、粉砂岩为主,第2段、第3段、第4段下部以砂岩为主,上部以泥岩、粉砂岩为主。根据瓦窑堡组顶部区域不整合面、第1段、第3段以及第4段底部河流下切谷冲刷面、瓦窑堡组底部与其下伏地层间地层颜色及岩性突变面等层序界面,将瓦窑堡组划分为3个三级层序,其中层序I对应瓦窑堡组一段和二段,层序Ⅱ对应瓦窑堡组三段,层序Ⅲ对应瓦窑堡组四段和五段。通过统计各个三级层序内的岩性数据,绘制地层厚度、砂泥比、煤层厚度等值线图,以三级层序为作图单元,恢复各层序的古地理格局,主要的古地理单元为河流、三角洲和湖泊,物源位于研究区东北部。层序Ⅲ的聚煤作用明显优于层序Ⅰ和层序Ⅱ,最有利于成煤环境为三角洲平原分流间湾,聚煤中心大致位于石湾镇—玉家湾镇—安塞县一带。
[Abstract]:The sedimentary facies, coal accumulation model, sequence stratigraphic framework and lithofacies paleogeography of the Wayaobu formation of the late Triassic in the eastern part of Ordos Basin are studied based on the data of borehole core and logging curve. The Wayaobu formation is divided into five sections according to lithology, in which the first section at the bottom and the fifth section at the top are dominated by mudstone and siltstone, the second, the third and the fourth are dominated by sandstone, and the upper by mudstone and siltstone. According to the unconformities at the top of the Wayaobu formation, the first, the third and the fourth member bottom of the fluvial valley scouring surface, and the sequence interface between the bottom of the Wayaobu formation and its underlying strata, such as the abrupt change surface of formation color and lithology, etc. The Wayaobu formation is divided into three third-order sequences, in which sequence I corresponds to the first and second member of the Wayaobu formation, sequence 鈪，
本文编号：2320396
[Abstract]:The sedimentary facies, coal accumulation model, sequence stratigraphic framework and lithofacies paleogeography of the Wayaobu formation of the late Triassic in the eastern part of Ordos Basin are studied based on the data of borehole core and logging curve. The Wayaobu formation is divided into five sections according to lithology, in which the first section at the bottom and the fifth section at the top are dominated by mudstone and siltstone, the second, the third and the fourth are dominated by sandstone, and the upper by mudstone and siltstone. According to the unconformities at the top of the Wayaobu formation, the first, the third and the fourth member bottom of the fluvial valley scouring surface, and the sequence interface between the bottom of the Wayaobu formation and its underlying strata, such as the abrupt change surface of formation color and lithology, etc. The Wayaobu formation is divided into three third-order sequences, in which sequence I corresponds to the first and second member of the Wayaobu formation, sequence 鈪，
本文编号：2320396
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