中国不同地质时代煤层瓦斯区域分布特征

DISTRIBUTION OF COAL SEAM GAS IN COAL-BEARING STRATA OF DIFFERENT PERIODS IN CHINA

通过完成1：200万中国煤层瓦斯地质图项目，系统地整理了中国近2000对矿井瓦斯涌出和谋与瓦斯突出资料，划分出88个瓦斯带，研究了中国不同地区、不同地质时代含煤地层的煤层瓦斯保存和生成条件，结合中国诸含煤地层的成煤条件、地质演化历史和煤化作用等，论述了不同时代含煤地层的煤层瓦斯分布特征。其中，石炭-二叠纪含煤地层成煤条件较好，深成煤化作用程度较高、盖层厚，是形成中国高瓦斯区。高瓦斯带。高瓦斯矿井的主要煤层。早、中侏罗世含煤地层虽然分布面积广、成煤条件好、资源量居诸含煤地层之首，但由于煤化程度偏低，又加上瓦斯风化带普遍较深，多为低瓦斯矿井和低瓦斯带分布。但在中国西部，大型含谋盆地周边多受逆冲推覆构造控制，对煤层瓦斯保存有利。

In this paper, a large amount of inforrnation about gas ernission and outburst in twothousand-couple of mines within China is collected and analysed systematically based on the geological map of coal seam gas of China (scale 1: 2 000 000), and eighty-eight different coal searngasbearing coal bed belts are also delimited. In addition, according to the structural features andbackground of different coal mine fields, the content of coal seam gas or amount of gas inflow,the sedimentary characteristics, the distribution of coal seam gas of different peried in mines orcoal fields are studied at the same time. It is found that the Carboniferous-Permian coal fieldsoccur with high gas-bearing searns. They possess the higher coalification degree and the betterconditions under which the coal searn gas might be generated and preserved. As the coal seamsof Lower-Middle Jurassic in China are weathered intensively, their gas content is low. In themarinal belts of huge coal basins in the west of China, the gas is well preserved under the control of reverse nappe structures.