鄂尔多斯盆地东北缘补连塔矿区延安组煤岩沉积古环境分析  

Sedimentary paleoenvironment analysis of coal and rock in Yanan Formation in Bulianta mining area,northeastern margin of Ordos Basin

作　　者：李国利 李斌 崔春兰 董振国 LI Guoli;LI Bin;CUI Chunlan;DONG Zhenguo(Inner Mongolia Coal Geological Exploration(Group)472 Co.,Ltd.,Tongliao 028000,Inner Mongolia,China;Hanshan Normal College,Chaozhou 521014,Guangdong,China;CHN Energy Trading Company,Beijing 100011,China;Shenhua Geological Exploration Co.,Ltd.,Beijing 100011,China)

机构地区：[1]内蒙古煤炭地质勘查(集团)四七二有限公司,内蒙古通辽028000 [2]韩山师范学院,广东潮州521014 [3]国家能源集团煤炭经营分公司,北京100011 [4]神华地质勘查有限责任公司,北京100011

出　　处：《矿产勘查》2024年第12期2259-2269,共11页Mineral Exploration

基　　金：神华神东电力有限责任公司科技创新项目“宁东煤矿南部区构造特征及煤层对比控制(SGEG-FZB-2024-D4-KX-752)”资助。

摘　　要：延安组煤岩含有多种元素,是地质历史时期的地球化学记录,某些特定元素丰度和组合特征能够较好地反映构造背景及古沉积环境,具有指相意义。当前对补连塔矿区延安组煤岩元素特征及沉积环境的协同演化方面缺乏全面系统的研究,为了查明其含煤地层的地球化学特征和沉积环境,对该区延安组煤岩样品进行分析化验,开展地球化学、元素示踪等方面的分析和研究,结果表明:样品K_(2)O/Na_(2)O-SiO_(2)、SiO_(2)/Al2O3-K_(2)O/Na_(2)O特征反映延安组物源区构造背景相对稳定,主要与活动大陆边缘—大陆岛弧相关;硅铝系数(Si/Al)为2.69、铝钛系数(Al/Ti)为21.24,辨别延安组煤岩矿物物源以中性岩(镁铁质岩石)类为主,样品成分变异指数(ICV)均值为1.92,代表为首次沉积的产物;常量元素含量和比值辨别延安组含煤地层古气候温暖潮湿,古水体较为稳定,为半咸水沉积环境,沉积条件较为稳定,主要发育湖泊三角洲沉积体系,从延安组沉积早期(5#煤组)到延安组沉积晚期(1#煤组),古气候由温湿气候转为半湿润气候,水体古盐度逐渐增加,古氧化还原环境为低位泥炭沼泽的还原环境,为有利于煤炭聚集和演化的沉积环境,沉积环境研究和恢复有助于揭示延安期聚煤规律,可为煤炭富集区预测和煤炭的高效开采提供地球化学依据。The Yanan Formation coal rock contains multiple elements and is a geochemical record of geological history.The abundance and combination characteristics of certain specific elements can better reflect the tectonic background and ancient sedimentary environment,and have indicative significance.However,there is currently a lack of comprehensive and systematic research on the elemental characteristics of coal and rock in the Yanan Formation of the Bulianta mining area and their synergistic evolution with sedimentary environments.In order to investigate the geochemical characteristics and sedimentary environment of the Yanan Formation coal bearing strata in the Bulianta mining area,utilize analysis and testing results of samples,the geochemical characteristics and element tracing of the Yanan Formation coal rocks in the area were analyzed and studied.The results showed that the K_(2)O/Na_(2)O-SiO_(2) and SiO_(2)/Al2O3-K_(2)O/Na_(2)O characteristics of the samples reflected the relatively stable tectonic background of the Yanan Formation source area,mainly related to the active continental margin continental island arc;The silicon aluminum ratio(Si/Al)is 2.69 and the aluminum titanium ratio(Al/Ti)is 21.24.The mineral source of Yanan Formation coal rock is mainly neutral rock(magnesian iron rock),and the average composition variation index(ICV)of the sample is 1.92,representing the product of the first sedimentation;The identification of the content and ratio of constant elements in the coal bearing strata of the Yanan Formation indicates that the ancient climate was warm and humid,and the ancient water bodies were relatively stable.It was a semi saline sedimentary environment with stable sedimentary conditions,mainly developed in the lake delta sedimentary system.From the early stage of Yanan Formation sedimentation(Coal Formation 5)to the late stage of Yanan Formation sedimentation(Coal Formation 1),the ancient climate shifted from warm and humid climate to semi humid climate,and the ancient salinity of the water gra

关 键 词：侏罗系延安组 元素地球化学 物源分析 古沉积环境 地质勘查工程 

分 类 号：P595[天文地球—地球化学] P531[天文地球—地质学]