鄂尔多斯盆地中生界聚煤规律及对多能源共存富集的贡献

On the Coal Accumulating Law of Mesozoic and Its Contribution to the Concentration of Multiple Energy Resources in Ordos Basin

鄂尔多斯盆地发育三套含煤地层,石炭—二叠纪含煤地层形成于北方大型聚煤盆地,三叠纪含煤地层形成于大型内陆坳陷盆地,侏罗纪含煤地层则形成于鄂尔多斯大型坳陷聚煤盆地。鄂尔多斯盆地中生界主要由冲积扇沉积、河流沉积、湖泊沉积和三角洲沉积等4种沉积体系所组成,在盆地充填整个序列中,上述沉积体系呈旋回式叠覆,同一时期不同沉积体系构成一个完整的体系域。不同沉积环境下发育的不同沉积体系及其空间上的配置情况为鄂尔多斯盆地多种能源矿产的形成,特别是多层系成煤、多层系生油气、多旋回成煤和油气奠定了可靠的地质基础。煤的聚积成为鄂尔多斯盆地主体能源矿产,与之相伴生的矿产如煤成气、煤层气等,煤与石油也有一定的亲缘关系,因此,盆地的聚煤作用对多种能源矿产共存具有关键性贡献。

Three sets of coal bearing strata have developed in Ordos basin, in which the Permian-Carboniferous one formed in the coal accumulating basin of large scale in the north, the Triassic one formed in the inland depressed basin of large scale, and the Jurassic one formed in the depressed coal accumulating basin of large scale in Ordos. The strata of Mesozoic were dominated by the alluvial fan depositional system, the river depositional system, the lake depositional system and the delta depositional system. In the whole filling sequence, the depositional systems of above take on the patterns of superposition. The different depositional systems formed in the same period have composed the integrated system tract. The different depositional systems formed in the different depositional environment and its collocating circs in the space have established the stable geologic bases for the formation of the multiple energy resources in Ordos basin, especially the coal formation of the multiple strata, the oil and gas formation of the multiple strata, the coal formation and the oil and gas of the multiple cycle. The coal accumulation has been the main energy resource in Ordos basin, the concomitant mineral resources are the coal-forming gas and the coal-type gas and so on. The coal has some relative relation with the petroleum. So the coal accumulation possesses the key contribution to the coexistence of the multiple energy resource.