活鸡兔井田延安组煤层地球化学特征与沉积古环境研究  

Study on geochemical characteristics and sedimentary paleoenvironment of Yan′an Formation Coal Seam in Huojitu Mine Field

作　　者：李国利 崔春兰 董振国 王秀青 Li Guoli;Cui Chunlan;Dong Zhenguo;Wang Xiuqing(Inner Mongolia Coal Geological Exploration(Group)472 Co.,Ltd.,Tongliao 028000,China;National Energy Group Coal Management Branch,Baotou 014010,China;Shenhua Geological Exploration Co.,Ltd.,Beijing 100011,China;Inner Mongolia Autonomous Region Surveying and Mapping Geographic Information Center,Hohhot 010020,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]国家能源集团煤炭经营分公司,内蒙古包头014010 [3]神华地质勘查有限责任公司,北京100011 [4]内蒙古自治区测绘地理信息中心,内蒙古呼和浩特010020

出　　处：《能源与环保》2023年第5期55-63,共9页CHINA ENERGY AND ENVIRONMENTAL PROTECTION

基　　金：国家能源投资集团有限责任公司科技创新项目(GJNY-18-76)。

摘　　要：通过对活鸡兔井田钻孔岩心的采样和测试分析,查明延安组煤层显微煤岩特征、物理化学性质、煤灰成分等,采用煤层CIA和ICV方法对物源区风化程度和沉积过程进行分析,采用碳氮比(C/N)方法对成煤植物类型进行判别,采用镜/惰比(V/I)、元素比值等方法对其古沉积环境进行了恢复。研究结果表明:延安组煤具有水分低、灰分低、挥发分中等、含硫特低的特点,煤层中氧化物主要为SiO_(2)、Al 2O_(3)、CaO、Fe 2O_(3)、SO_(3)等,煤层矿物物源区化学风化作用程度中等,沉积物未经历物质的再循环过程,成煤植物来源主要为湿润气候条件下发育的裸子植物体;延安组沉积期古气候较潮湿,主要为低位泥炭沼泽沉积环境,古水体较浅,呈半咸水的水体环境,古生产力较高,有利于煤炭的聚集和成煤演化;从延安组沉积早期(5煤组)到延安组沉积晚期(1煤组),煤系地层主要发育湖泊三角洲平原沉积体系,古气候主要为温湿、半湿润气候,水体古盐度中等,主要为半咸水相,古氧化相为弱还原环境。Through the sampling and test analysis of drilling cores in Huojitu Mine Field,the micro-coal rock characteristics,physical and chemical properties,coal ash composition,etc.of the Yan′an Formation coal seam were identified.The weathering degree and sedimentary process of the source area were analyzed using coal seam material CIA and ICV methods.The carbon nitrogen ratio(C/N)method was used to distinguish the types of coal forming plants.The ancient sedimentary environment was restored using methods such as mirror/inert ratio(V/I)and element ratio.The research results show that the coal of Yanan Formation has the characteristics of low moisture,low ash,medium volatile content and extremely low sulfur content.The Oxide in the coal seam are mainly SiO_(2),Al 2O_(3),CaO,Fe 2O_(3),SO_(3),etc.The provenance is moderate weathering,and the sedimentary material cycle has not been experienced during the deposition process.The source of coal-forming plants is mainly gymnosperms developed under humid climate conditions;the paleoclimate of the Yanan Formation was relatively humid during the depositional period,mainly low-level peat swamp depositional environment,paleowater bodies shallow freshwater environment with brackish water facies,high paleoproductivity,favorable for coal accumulation and coal formation evolution.The strata mainly develop lake delta plain sedimentary system,the paleoclimate is mainly warm-humid and semi-humid climate,the paleo-salinity of the water body is moderate,mainly is brackish aqueous phase,and the paleo-oxidative phase is a weak reducing environment.

关 键 词：鄂尔多斯盆地北部 侏罗系 元素地球化学 物源分析 古沉积环境 

分 类 号：P595[天文地球—地球化学] P531[天文地球—地质学]