贵州大方地区龙潭组煤系地层沉积环境分析

Sedimentary Environment Analysis of Longtan Formation Coal-bearing Stratum in Guizhou Dafang Area

通过观察大方地区龙潭组地层的野外特征并结合沉积学的理论知识,对龙潭组含煤地层特征、沉积环境、影响因素及分布规律进行研究,建立了2个龙潭煤系的标志层和3个含煤组,龙潭组沉积相类型主要为沼泽相和海岸相,沼泽相为龙潭组主要的成煤环境。凹陷的古地理环境、频繁的海退海进、古气候和丰富的植被是控制该区龙潭组含煤地层形成的主要原因。受构造和海退海进影响,含煤地层沿NNE向及NE向展布。

By observing the characteristics of the Longtan formation in Dafang area and combining the theoretical knowledge of the sedimentology, the characteristics of the coal-bearing stratum, the sedimentary environment, the influencing factors and the distribution law of the Longtan formation are studied. Two marked beds and three coal bearing groups of Longtan coal measures have been set up. The sedimentary facies of the Longtan formation are mainly swampy facies and coastal facies. The swamp facies is the main coal forming environment of the Longtan formation. The depressed paleogeographic environment, frequent regressive and transgression, humid paleoclimate and abundant vegetation are the main reasons for controlling the formation of coal-bearing in Longtan formation. Affected by tectonic and regressive and transgression, coal-bearing stratum are distributed along NNE direction and NE direction.