中国南方下寒武统石煤的特征、沉积环境和成因

CHARACTERISTICS ,SEDIMENTARY ENVIRONMENT AND ORIGINOF THE LOWEKR CAMBRIAN STONE -LIKE COAL IN SOUTHERN CHINA

在早寒武世，中国南方存在着四种类型的含石煤地层一南岭型、扬子型、江南型和华南型，其中的石煤在量和质的方面均各不用问，据研究，这主要与当时的沉积背景（一个浅水台地、一个深水盆地和三个深水大陆斜坡）差异有关。作者通过对石煤的分布、厚度、物质组分、岩石类型、物理化学性质和伴生元素的讨论，认为其形成机理为：海平面上升，由上升洋流携带富养海水在沉积速率缓慢和少泥的条件下，促使菌藻类大量发育，并由此引起海底缺氧环境；菌藻类死亡后沉积在海底，经过复杂的成岩变质作用就形成了石煤。

During the early Cambrian period,there were four kinds of strata containing stone-like coal in southern ChinaNanling,Yangtze,Jiangnan and Huana types,in which stone-like coal was different in quality and qnd quantity. Based on the study,this was mainly reat-ed with the difference of sedimentary settings(shallow-water platform,deep-water basinand deep-water continental slope ). According to distribution, thickness, material copo-nents. rypes, asscciated elements, physical and chemical properies etc. of the stone-likecoal, the authors think that the genetical machanism of the stine-like coal was as following:cwing to the rise of sea level and nutrititon-atundent sea-water carried by upwelling,alarng amount of thallogen occurred in the condition of the slower sedimentary rate and lack-ing of clay and rnd resulted in oxygen-deficient environment in lower water and sea floor. After thallogen died. they deposited in the sea floor and the stone-like coal was formedthrough complicated diagenesis and metamorphisn.