织纳煤田西部坐拱地区龙潭组 C_3 煤层形成环境和聚煤特征

Depositional Enviroments and Coal—forming Characteristics of Coal Ca of Longtan Formation in Zhuogong,Western Guizhou

本文主要讨论了坐拱一带龙潭组 C_3煤层的形成环境和聚煤特征。研究表明:C_3煤层形成对的下伏碎屑岩段为一发育在上三角洲平原上的网状河流体系。C_3煤层形成后,本区先后发育泻湖—海湾沉积和潮坪沉积,构成向上变浅的沉积序列。C_3(?)层的聚煤特征明显受其沉积时的沉积环境和沉积后沉积环境的影响。

Mainly disscussed in this paper aye the depositional enviroments and coal—forming characteristics of coal C_3 in Longtan Formation.The lower clastic member under coal C_3 is interperted as deposits of anastomosed river system on the upper delta plain.The limestone and clastic member above coal C_3 is considered as low—energy subtidal and intertidal zone deposits which constitute a sallowening upward sequence.The thickness, lataral extent of coal C_3 are mainly affected by the predepositional enviroments.The sulphur and ash content of coal C_3 is mainly affected by the contemporaneous and postdepositional enviroments.