琼东南盆地崖城组沉积特征及成煤环境

基于琼东南盆地各凹陷含煤地层岩心、测井等资料，以及崖城组岩石学、煤岩学及煤质学资料，研究了该盆地主要含煤地层崖城组的沉积、聚煤特点及成煤环境。结果显示:崖城组主要由含砾粗砂岩、粗砂岩、中砂岩、泥岩、碳质泥岩和煤组成，属于断陷盆地晚期的沉积；琼东南盆地以浅海周缘扇三角洲和滨海带为主要成煤环境及聚煤模式，成煤环境基本上与我国南方古近纪近海型成煤环境类似。 

Depositional characteristics and coal forming environment of Yacheng Formation,Qiongdongnan basin

The depositional characteristics, coal-accumulation law and coal forming environment of Yacheng Formation in coal-bearing strata are studied based on the analysis of the core, logging, and data of petrology, anthracology and coal property. On the basis of the analysis, the coal accumulation model was came up. Yacheng Formation can be divided into three members, which are memberⅠ, member Ⅱ and member Ⅲ. Yacheng Formation is the later period sedimention of graben basin, which was composed of peddy sandstones, grit, medium-sandstone, mudstone, carbargilite, caustobiolith(coal). Sandstones have some instable constituents, such as feldspar, detritus, mica and so on in which quartzose arkose, lithic arkosic wacke and so on are more common.Mudstone is rich in plant detritus and has higher organic content. Coal accumulation model of fan dalta near the shallow sea and shoreland was found in Qiongdongnan basin. And the coal forming environment is basically similar with the paralic one in Paleogenein period of South China. So many coal seams are of the main characteristics. Marine fossils and glauconite and other marine authigenic minerals can be found. The terrestrial higher plants (pteridophytes) and a few aquatic plants became the main coal forming plants.