大柳塔煤矿活鸡兔井束鸡沟小窑延安组烧变岩地质特征及地质灾害防治

Geological Yan’an Formation Burnt Rock Geological Features and Geological Hazard Control in Shujigou Small Coalmine,Huojitu Minefield,Daliuta Coalmine

大柳塔煤矿活鸡兔井束鸡沟小窑1-2上煤层和1-2煤层大部分自燃后缺失,部分地区1-2煤层有少量残留。煤层上部形成烧变岩。认识烧变岩地质特征可以为火烧区煤层及地层对比提供理论依据,为煤田开采提供重要的参考信息。经研究,1-2上煤层充分燃烧后,煤层之上的烧变岩,颜色上从下向上为褐色-红褐色-砖红色-浅粉色-灰白色,向上逐渐变浅,岩性上从下向上可以区分出熔结角砾岩、烧裂岩、块状烘烤岩、层状烘烤岩,裂隙逐渐减少;1-2煤层燃烧不充分,之上的烧变岩为熏烤岩,岩性为浅粉色碎屑岩。烧变岩中熔结角砾岩、烧裂岩具备良好的孔隙裂隙空间和储水构造条件,补给条件较好,是良好的富水区,煤田开采时注意保护地下水,防止污染与破坏。熔结角砾岩、烧裂岩中的地下水中极易溶解、存储有害气体,在煤田开采中需做好有毒气体泄露的防范措施。烧变岩中的块状烘烤岩为一类优良的建筑材料,可以用于建筑选材。烧变岩地形地貌也是一类重要的旅游景观。

Most of coal Nos.1-2 U and 1^-2 in the Shujigou small coalmine,Huojitu minefield,Daliuta coalmine are hiatus after spontaneous combustion;while coal No.1^-2 has a small amount of residue in local areas;while coal overburden have been turned into burnt rocks.To understand burnt rock geological features can provide theoretical basis for coal seams and strata correlation and important reference information for coal exploitation in burnt area.After analysis has considered that the color of coal No.1-2 U overburden burnt rock from bottom to top gradually changed lighter from brown,reddish brown,brick red,light pink to grayish white;lithologically from welded breccia to pyrogenic fractured rock,blocky baked rock to bedded baked rock with gradually reduced fractures.If coal No.1^-2 inadequately combusted,overburden burnt rock is called as“fire fumigated rock”,a kind of light pink colored clastic rock.The welded breccia and pyrogenic fractured rock in burnt rocks have good conditions of void,fractured spaces and good for water reservoiring,thus the favorable water-rich zones.During the coal mining should pay attention on groundwater protection,prevent pollution and destruction.Groundwater in welded breccia and pyrogenic fractured rock is very easy to dissolve and store harmful gases,thus during coal exploitation,countermeasures to poisonous gases leakage need to be done.Blocky baked rock in burnt rocks is category I excellent building material can be used in construction.Burnt rock topographic features also a kind of tourism landscape.