柴北缘东部北大滩地区中侏罗统石门沟组控煤因素

Coal control factors of Middle Jurassic Shimengou Formation in Beidatan area, east part of the northern Qaidam basin

  • 摘要: 青海省北大滩地区煤炭勘查工作的关键是沉积期的聚煤环境和沉积前后构造作用对煤层赋存的控制作用。为明确柴北缘东部北大滩地区石门沟组的控煤因素,有效指导该含煤区的煤炭勘查工作,基于野外露头、钻孔、地球物理勘探等地质资料,在分析北大滩地区石门沟组聚煤环境和构造作用的基础上,从聚煤环境、古隆起和断裂、向斜等方面深入探讨了石门沟组的控煤因素。其中,扇三角洲平原分流河道间的泥炭沼泽和滨湖环境的滨湖沼泽是有利的成煤环境,控制着煤层横向发育、分布特征;古隆起控制着有利聚煤区和煤层分布区;北大滩向斜内部次级背斜和逆断层的上盘控制着煤层埋藏深度,煤层埋藏浅降低了后期煤炭勘查的难度。

     

    Abstract: The key of the coal exploration in Beidatan area of Qinghai Province is the coal accumulation environment in the sedimentary period and the control of coal seam occurrence by tectonic action before and after sedimentation. To identify Shimengou Formation coal controlling factors in Beidatan area, east part of the northern Qaidam basin, effectively guide the coal exploration of the coal bearing area, through field outcrops, drilling, geophysical prospecting and other geological information system, based on the analysis of coal accumulating environment and structural function of Shimengou Formation in Beidatan area, the control factors of coal were deeply discussed from coal accumulation environment, paleo-uplift, fault and syncline. Among them, the peat marshes and lakeside marshes between distributary channels in fan delta plain were favorable coal-forming environments, which controlled the transverse development and distribution of coal seams; the paleo-uplift controled the favorable coal-accumulating area and coalbed distribution area; the upper wall of the secondary anticline and reverse fault in the Beidatan syncline controlled the burial depth of coal seams. Shallow burial depth of coal seams reduced the difficulties in later coal exploration.

     

/

返回文章
返回