鄂尔多斯盆地西缘断褶带南部二叠系山西组沉积特征及煤炭资源勘查潜力

Sedimentary characteristics and coal resources exploration potential of Permian Shanxi Formation in the south of fault and fold belt in west margin of southern Ordos basin

研究区位于鄂尔多斯盆地西缘断褶带南部的平凉市安国—峡门—小湾子一带。通过对该区二叠系山西组沉积特征研究,对赋煤地质条件和煤炭资源勘查前景进行了评价。本区二叠系山西组含煤沉积、成煤条件受古隆起及其决定的古地理环境的影响,沉积物源供给区主要为研究区南部,沉积环境为曲流河及三角洲,沉积期后构造作用导致了已沉积地层的剥蚀、变形等,致使二叠系山西组煤层在研究区分布面积小、结构复杂、稳定性差、原煤灰分高。本区山西组含煤地层由于受多种因素的影响和控制,区内未能形成并保留规模较大的煤田,找煤工作应选在安国—峡门—小湾子向斜及周边进行。

The study area is located in the south of fault and fold belt in west margin of Ordos basin in Anguo-Xiamen–Xiaowanzi area of Pingliang City. Through the study on the sedimentary characteristics of Permian Shanxi Formation in the area, the geological conditions of coal occurrence and coal resources exploration prospect were evaluated. The coal-bearing sedimentary and forming conditions of Permian Shanxi Formation were influenced by ancient uplift and pa-leogeographic environments, the south of the study area was the main sediment supply source area, meandering river and delta constituted sedimentary environments, the action of the post depositional structure caused erosion and deformation of the sedimented strata, etc., inducing small distribution area, complex structure, poor stability and high ash content of seams in Permian Shanxi Formation in the study area. Due to influence and control of multiple factors, coal-bearing strata of Shanxi Formation in the area failed to form and remain large coal field. Searching for coal should be done in Anguo-Xiamen–Xiaowanzi syncline and the surrounding area.