内蒙古贺兰山煤田二道岭矿区直罗组成煤环境分析

二道岭矿区侏罗系的成因属鄂尔多斯中生代盆地西缘的陆相碎屑沉积,岩石地层自下而上为富县组、延安组、直罗组和安定组。以往认为鄂尔多斯盆地的侏罗系延安组为含煤岩系,其他均为不含煤的地层,在近几年来的勘查中,发现直罗组也存在具有一定分布面积的可采煤层,笔者通过直罗组岩石露头、钻孔岩心和测井曲线的分析研究,划分了直罗组沉积相,并探索了直罗组的聚煤规律,对煤层进行了预测。研究认为,直罗组属典型的河流相沉积,进一步可细分为河床亚相、河漫滩亚相和漫滩沼泽亚相。煤层形成于漫滩沼泽亚相,富煤带的展布受控于河床亚相砂体。

Coal Forming Environment of Zhiluo Formation in Erdaoling Mine of Lanshan Coal Field, Inner Mongolia

The Erdaoling mine is located on the western margin of the Mesozoic Odors basin and belongs to continental clastic deposit during the Jurassic period.From the bottom up,the strata are the Fuxian,the Yan'an,the Zhiluo and the Anding Formations.In the past,it was thought that only the Yan'an Formation contains coal in the Jurassic systerm of the basin.However,recent explorations have shown that the Zhiluo Formation also has some minable coal seams in a certain area.After study of rock outcrops,well logs,borehole cores,the sedimentary facies of the Zhiluo Formation has been divided and the rule for coal accumulation was explored,and moreover,the coal-bearing strata were predicted.The author suggests that the Zhiluo Formation belongs to the typical fluvial sedimentary facies,which cab be further refined to the channel,flood-plain and backswamp microfacies.Coal seams are mainly formed in the backswamp microfacies and the spatial distribution of the coal seams is under control of the sand bodies of the channel microfacies.