东胜煤田西北缘延安组层序及成煤古地理特征  

Sequence and Coal-forming Paleogeographic Characteristics of Yan’an Formation in the Northwestern Margin of Dongsheng Coalfield

作　　者：梁圣建 黄兴龙 刘佳敏 王平丽[2] 李增学[2] 李晓静[2] 李旭超 冯凯 LIANG Shengjian;HUANG Xinglong;LIU Jiamin;WANG Pingli;LI Zengxue;LI Xiaojing;LI Xuchao;Feng Kai(Shandong Provincial Institute of Coal Geological Planning and Exploration,Ji’nan,Shandong 250104;Shandong University of Science and Technology,Qingdao,Shandong 266590;Sinopec North China Oil&Gas Branch,Zhengzhou,Henan 450006)

机构地区：[1]山东省煤田地质规划勘察研究院,山东济南250104 [2]山东科技大学,山东青岛266590 [3]中国石油化工股份有限公司华北油气分公司,河南郑州450006

出　　处：《中国煤炭地质》2023年第12期10-16,9,共8页Coal Geology of China

基　　金：国家自然科学基金项目(42072188,42272205)。

摘　　要：东胜煤田地处内蒙古自治区西南部,侏罗系延安组为重要的含煤地层,蕴藏的煤炭资源十分丰富。基于勘探区钻井岩心、测井、煤岩煤质测试分析资料,研究了东胜煤田西北缘延安组的层序地层格架和岩相古地理特征。采用含煤岩系层序地层学方法,通过识别层序界面,在研究区延安组划分出了3个三级层序,其中层序一、层序二为主要的含煤地层。采用岩相古地理方法,统计分析了研究区典型钻井延安组在不同层序的地层厚度、砂岩厚度、泥岩厚度、砂岩百分比、煤层厚度等重点数据,绘制了综合分析图件,恢复了研究区延安组岩相古地理格局。研究表明,层序一主要发育辫状河和曲流河沉积,层序二主要发育曲流河沉积。在岩相古地理分析基础上,结合研究区古植物、古气候及古构造特征,揭示了研究区聚煤规律:聚煤中心主要位于河道间河漫滩平原,湖侵体系域晚期和高位体系域晚期是主要发育时期,煤层具有层数多,厚度大并且发育稳定等特征。Dongsheng Coalfield is located in the southwest of Inner Mongolia Autonomous Region.The Jurassic Yan’an Formation is an important coal-bearing stratum with abundant coal resources.Based on the analysis data of drilling core,logging and coal quality test in the exploration area,the sequence stratigraphic framework and lithofacies paleogeographic characteristics of Yan’an Formation in the northwestern margin of Dongsheng Coalfield were studied.By using the sequence stratigraphy method of coal-bearing rock series and identifying the sequence interface,three third-order sequences are divided in the Yan’an Formation of the study area,among which sequence 1 and sequence 2 are the main coal-bearing strata.Based on the lithofacies paleogeography method,the comprehensive analysis maps were drawn by using the key data of stratigraphic thickness,sandstone thickness,mudstone thickness,sandstone percentage and coal seam thickness of different sequences in Yan’an Formation of typical drilling in the study area,and the lithofacies paleogeographic pattern of Yan’an Formation in the study area was restored.The study shows that sequence 1 mainly develops braided river and meandering river deposits,and sequence 2 mainly develops meandering river deposits.Based on the analysis of lithofacies paleogeography,combined with the characteristics of ancient plants,paleoclimate and paleostructure in the study area,the law of coal accumulation in the study area is revealed:The coal accumulation center is mainly located in the interchannel flood plain,and the late stage of the lake transgressive system domain and the late stage of the high-level system domain are the main development periods.The coal seam has the characteristics of many layers,large thickness and stable development.

关 键 词：延安组 层序划分 曲流河沉积体系 成煤古地理 东胜煤田 

分 类 号：P618.11[天文地球—矿床学]