云南省煤矿瓦斯赋存构造控制规律与瓦斯分带划分

Tectonic control rule and zoning division of coalmine gas occurrence in Yunnan province

瓦斯赋存规律认识不清,是导致煤矿瓦斯突出灾害频发的根本原因。应用瓦斯赋存地质构造逐级控制理论,结合云南省煤矿瓦斯地质图编制资料,探讨了云南省煤矿瓦斯赋存构造控制规律,进行了瓦斯分带划分及瓦斯带特征分析。研究结果表明:印支期,NW向构造发生右行活动,形成压扭性构造,破碎煤体、形成构造煤。燕山期,滇东和滇东北形成了一系列NE-NNE向平缓褶皱,煤系地层保存较完整;而滇东南断裂活动发育,煤系地层遭受了严重的破坏。喜山运动第Ⅰ幕,云贵高原抬升,侏罗纪、白垩纪地层风化剥蚀殆尽,瓦斯大量释放;喜山运动第Ⅱ幕,NE向构造带强烈挤压、冲断、推覆,破碎煤体、形成构造煤,有利于瓦斯保存。新构造运动时期,滇东NNE、NE向构造带应力集中,易引发瓦斯突出;滇中高瓦斯区NW、NNW向构造带应力集中,易引起瓦斯突出事故。将云南省煤矿瓦斯赋存分布划分了两个高突瓦斯带和两个瓦斯带,即滇东高突瓦斯带、华坪祥云一平浪高突瓦斯带、滇中瓦斯带和滇西滇南瓦斯带。

Unclear understanding of gas occurrence rule is a root reason of frequent gas outburst disasters. Basing on tectonic control theory of gas occurrence, combining with datum of Yunnan Province gas-geology map, the tec- tonic control rule and zoning division of gas occurrence were discussed. The results showed that NW structures were dextrorotary, which formed compresso-shear structures and tectonic coal during the Indosinian. During Yanshanian period, a series of NE-NNE gentle folds were formed in the eastern and northeast Yunnan Province, therefore coal measure strata were well preserved. But faulted structure developed well in the southeastern region, coal measure strata were destroyed severely. At the first phase of the Himalayan movement, Jurassic and Cretaceous stratum were weathered and denuded seriously due to Yunnan-Guizhou Plateau uplifting, so amounts of mine gas escaped. At the second phase of the Himalayan movement, NE structure belts were extruded and thrusted, coal body was broken and tectonic coal was formed, which was helpful to preserve mine gas. During neotectonics period, the tectonic stress of NNE, NE structure belts in the eastern region and the NW, NNW structure belts in high-gas zones of the western region concentrated, which easily leads to gas outburst. Coalmine gas occurrence and distribution in Yunnan Province were divided into 2 high-gas outburst zones and 2 gas zones, including eastern Yunnan high-gas outburst zone, Huaping-Xiangyun-Yipinglang high-gas outburst zone, central Yunnan gas zone and western-southern Yunnan gas zone.