大杨树盆地中部九峰山组上段沉积环境及聚煤模式

Sedimentary environment and coal-accumulation pattern for the Upper Jiufengshan Formation in the central of Dayangshu Basin

大杨树盆地煤层赋存状态复杂,煤田勘探一直没有突破。为了确定有利找煤区域,应用沉积学基本原理,结合钻孔资料,沉积构造及组合,并编绘砾岩、砂岩、泥岩厚度等值线,对大杨树盆地中部九峰山组上段的沉积环境和聚煤模式进行分析。认为研究区内沉积环境主要为冲积扇、扇三角洲和湖泊。研究发现,煤层主要分布于扇三角洲平原和滨浅湖沉积环境内并围绕半深湖—深湖沉积区呈带状分布,并且区域内发育有两种类型的聚煤模式:大杨树—达尔滨含煤区属于进积型聚煤模式,马尾山—春林沟含煤区为退积型聚煤模式。虽然两含煤区具有不同的聚煤模式,但发育有类似的聚煤环境,综合煤层的聚集模式与分布规律认为马尾山—春林沟含煤区是理想的勘探区域。

Abstract：Coal seam occurrence of Dayangshu Basin is complicated, coal exploration has yet to break. In order to confirm the advantageous coal mineralization regions, by applying the basic principles of sedimentology, combined with borehole data, sedimentary structure and composition. The authors drawn the thickness contour maps of conglomerate, sandstone and mudstone, analyzed the sedimentary environment and coal-accumulating pattern of the Upper Jiufengs- han Formation in central Dayangshu Basin. The results show that the main sedimentary environment is alluvial fan, fan- delta and lake in the studied area. Also, the coal seam mainly distributes in the fan delta plains and shore-shallow lacus- trine sedimentary environment and appears zonally surround the semi-deep lake to deep lake sedimentary area, where two types of coal accumulations exist, ie. , progradational coal-accumulation pattern in the Dayangshu-Daerbin coal-bearing area and retrogradational coal-accumulation pattern in the Maweishan-Chunlingou coal-bearing area. Although coal-accu- mulation patterns of the two coal-bearing areas are different, they are similar in coal accumulation environment. Based on the coal-accumulation pattern and distribution law of coal seam, Maweishan-Chunlingou coal-bearing area is a potential exploration area. Key words： Dayangshu Basin ; Jiufengshan Formation ; sedimentary environment; sedimentary facies ; coal-accumulating pattern