南华北南缘下寒武统优质海相烃源岩初探

根据野外地质调查,在南华北南缘发现下寒武统海相泥质烃源岩。层位上主要分布于东坡组(豫西)/雨台山组顶部(淮南)及凤台组下部(淮南),岩性为灰黑色含磷泥页岩、泥页岩、深灰色泥灰岩;平面上主要分布于华北南缘大陆边缘及台缘斜坡区,海相泥页岩厚度呈现自北向南,自西向东增厚的趋势。该套海相泥质烃源岩有机质丰度高(有机碳1.7%),随厚度增大亦呈现变高的趋势,属Ⅰ型干酪根,热演化程度受重力滑动构造影响而偏高(R_o2.5%)。虽然厚度不大,但曾具有极强的生烃潜力,初步评价为优质烃源岩,是南华北南缘值得深入探索的海相天然气源岩。

Preliminary exploration of excellent marine hydrocarbon in lower Cambrian on the south margin of the north China

Based on field geological survey,excellent black mudstone - shale hydrocarbon was found to be developed in the South Margin of the North China Platform,which was mainly distributed in Dongpo formation(western Henan)/top of Yutaishan formation and bottom of Fengtai formation (southern Anhui).The lithology belongs to black mudstone -shale containing phosphor,shale,dark gray muddy limestone. In the plane,the source rock was mainly developed in Continental margin and the platform margin slope,the thickness presenting the trend of increasing,from north to south and from west to east.The organic matter abundance is high (organic carbon >1.7%),and increases with the thicker of thickness.It belongs to kerogenⅠand thermal evolution is higher and affected by gravity sliding tectonic(R_o> 2.5%). Although with the small thickness,it had a strong hydrocarbon potential and was evaluated to be a high - quality hydrocarbon source rock,which has the value of exploration.