黔西月亮田矿区龙潭组泥岩地球化学特征及指示意义

Geochemical Caracteristics and Significance of Mudstone of the Longtan Formation in YueLiangtian Mining Area,Western Guizhou

通过广泛调研前人研究成果、月亮田矿区地勘资料,区域地质背景,钻取并测试区内两口钻井的17件泥岩样品;运用地球化学指标指示沉积环境,对区内龙潭组泥岩地球化学特征及地质意义进行了详细研究。结果表明:区内龙潭组沉积主体时期长期处于温湿气候,利于植物繁殖;古水体以淡水环境为主,间或有短暂海侵;沉积水体以贫氧至厌氧的弱氧化至还原性环境为主,为区域聚煤作用提供了良好条件;龙潭组物源以来自大陆岛弧的玄武岩为主。研究结果符合贵州省大地构造背景,不仅进一步佐证了研究区在晚二叠世龙潭期作为沉降区,长期接受玄武岩物源沉积,也揭示了古沉积环境及物源区构造背景,为区域地质研究提供了新的理论支持。

The geochemical characteristics and geological significance of mudstone of the Longtan formation are studied in detail through extensive investigation of previous research results,geological data,regional geological background and 17 mudstone samples from two drilling Wells.The results showed that the main sedimentary period of the Longtan formation was in a warm and humid climate for a long time,which was conducive to plant reproduction.The ancient water bodies were dominated by fresh water environment with occasional transgression.The sedimentary water body is dominated by weak oxidation to reductive environment from poor oxygen to anaerobic,which provides good conditions for regional coal accumulation.The source of the Longtan formation is basalt from mainland island arc.The results are in line with the tectonic background of guizhou province,which not only further proves that the study area,as a subsidence area in the late Permian Longtan period,accepted the basalt source sediments for a long time,but also reveals the paleosedimentary environment and the tectonic background of the provenance area,providing theoretical support for regional geological research.