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

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.