河南晚石炭世含煤地层中的风暴异地煤
THE STORM ALLOCHTHONY COAL OF LATE CARBONIFEROUS COAL-BEARING FORMATION IN HENAN PROVINCE
-
摘要: 河南省晚石炭世含煤地层中,存在着因风暴作用强烈侵蚀滨海泥炭沼泽,而后通过风暴回流把泥炭物质和植物遗体长距离搬运到浅海环境再沉积的风暴异地煤。这种异地煤的直接顶底板是具有风暴沉积特征的浅海碳酸盐岩.煤破碎成粉砂级-泥级,煤层原生结构已完全看不到,煤层下部为含有大量海相动物化石的滞积层,中部为具有类似丘状层理的波状层,上部为水平纹层,其层序特征几乎可与煤层直接顶底板浅海碳酸盐风暴岩类比。研究这种异地煤的沉积背景和形成机制以及这种煤层所反映出的煤质特征、煤岩特征、沉积特征、层序及层序类型特征,不仅可以开拓出一种新型异地成煤类型而扩大煤地质学的研究领域,而且有助于研究古气候、古水深和煤岩层对比等问题。Abstract: There have been found storm allochthony coals in Upper Carboniferous in Henan Province, which redeposited in neritic environment when storm scoured strongly swamp in coastal plain and transported these materials into neritic environment. The direct bottom and top beds of this coal are both carbonatite with the chracteristics of storm deposits. Coal grade is silty-muddy and there are any primary structures in coal thin section. The sequence of coalbed is similiar to that of carbonate storm deposits in its bottom and top beds, which consists of lag bed with plentiful of marine fossils at the bottom, wavy laminated bed with hummocky cross bedding at the middle, and horizontal laminated bed at the top. This paper dealts with the chracteristics of coal quality, coal petrographics, the types of sequences, depositional setting and forming regimes of storm allochthony coal. These studies not only find a new type of coal-forming pattern and develop the research scope of coal geology, but also are helpful to study paleoclimate, paleoenvironment and coal correlation.