龙永煤田童子岩组层序地层格架与聚煤规律研究  

Sequence stratigraphic framework and coal-accumulating patterns of the Tongziyan Formation in the Longyong coalfield

作　　者：许福美[1] 姜琳 鲍道亮 刘明松[1] 邱占林[1] Xu Fumei;Jiang Lin;Bao Daoliang;Liu Mingsong;Qiu Zhanlin(School of Resource Engineering,Longyan University,Longyan,Fujian 364000)

机构地区：[1]龙岩学院资源工程系,福建龙岩364000

出　　处：《地质科学》2019年第4期1155-1166,共12页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：福建省自然科学基金项目(编号:2015J01170)资助.

摘　　要：龙永煤田位于我国华南晚古生代闽西南地体聚煤盆地中最主要的富煤带上,童子岩组是其主要含煤岩系.笔者在收集岩心、野外露头和测井等地质资料的基础上,运用层序地层学的基本理论和研究思路,对龙永煤田童子岩组进行了分析,确定了层序界线,阐明其层序地层格架,揭示了该煤田的聚煤规律.研究表明:童子岩组存在初始海泛面和最大海侵面两个关键界面.初始海泛面位于童子组二段的Ⅱ标志层底部,是三级层序(层序Ⅰ和层序Ⅱ)的分界面;最大海泛面位于童子组二段泥岩的顶部,是三级层序Ⅱ中海侵体系域与高水位体系域的分界面.层序Ⅰ包含6个四级层序(准层序S1~S6),层序Ⅱ包含6个四级层序(准层序S7~S12),其中层序Ⅰ对应文笔山组和童子岩组一段地层,层序Ⅱ对应童子岩组二段和三段地层.聚煤作用主要发生在高位体系域中,最重要的聚煤作用发育在障壁岛—泻湖相和滨岸湖泊相中,主采煤层主要发育在S3、S4、S9、S10和S12的5个准层序内.Longyong coalfield is the most important coal-rich belt which is located in the Late Paleozoic coal-accumulating basin in southwestern Fujian, South China. Tongzi Formation is the main coal-bearing rock series. On the basis of collecting geological data such as core, outcrop and well logging, the author analyzed Tongzi Formation in Longyong coalfield by using basic theory and research ideas of sequence stratigraphy, determined sequence boundaries, clarified its sequence stratigraphic framework and revealed the coal accumulation law of the coalfield. The results show that the Tongzi Formation has two key interfaces:The initial flooding surface and the maximum transgression surface. The initial flooding surface is located at the bottom of the No.Ⅱ key bed of the second segment of the Tongziyan Formation, and it is the interface of low-level system tract and transgressive system tract, and the interface of three-order sequence(sequence Ⅰ and sequence Ⅱ). The maximum flooding surface is located in the top of mudstones of the second segment of the Tongziyan Formation, which is the interface between the transgressive system tract and the high water system tract in the third-order sequence Ⅱ. Type-Ⅰ sequence contains seven fourth-order sequences(parasequence S1~S6), and Type-Ⅱ sequence contains six fourth-order sequences(parasequence S7~S12). Type-Ⅰ sequence corresponds to the Wenbishan Formation and the first segment of the Tongziyan Formation, and Type-Ⅱ sequence corresponds to the second and third segment of the Tongziyan Formation. Coal accumulation mainly occurs in the high-level system tract. The most important coal accumulation of the Tongziyan Formation is developed in barrier island-lagoon sedimentary environments. The coal seams are mainly developed in the S3, S4, S9, S10 and S12 parasequences.

关 键 词：层序地层 聚煤规律 体系域 初始海泛面 最大海泛面 童子岩组 

分 类 号：P618.13[天文地球—矿床学]