阿尔科马盆地是美国中部油区的一个古生界断陷盆地。宾夕法尼亚系的哈茨绍恩组是主要产气层之一。这个气藏自1910年开采七十多年来,还不断有新的发现。在盆地范围内这个组自下而上分为四层:下砂层、下煤层、上砂层、上煤层。两组砂层都是巨厚的条带形的分流河道砂岩及分流间河湾相的砂岩和砂质页岩。两组煤层紧贴着分流河道砂 The Alcoma Basin is a Paleozoic rift basin in the central United States. The Harz-Schoonn Formation of the Pennsylvania Department is one of the major gas layers. This gas reservoir has been continuously discovered since it was mined for more than 70 years in 1910. Within the basin, this group is divided into four layers from bottom to top: lower sands, lower sands, upper sands and upper sands. Both sets of sand layers are thick, strip-shaped distributary fluvial sandstones and fluvial-facies sandstone and sandy shale. Two sets of coal seam close to the distributary channel sand