补连塔煤矿中生界高分辨率层序地层与沉积环境演化

通过多口钻孔岩心、测井等资料，结合区域地质背景，对补连塔煤矿中生界进行层序地层及微相划分，总结其沉积环境演化规律。研究结果表明：补连塔煤矿中生界可以区分出7个长周期基准面旋回，13个中周期基准面旋回，在全矿区均可对比。从下向上，侏罗系延安组为三角洲沉积相，侏罗系直罗组和安定组为河流沉积相，白垩系志丹群为冲积扇沉积相。中生代从早到晚，补连塔煤矿由近坳陷湖盆三角洲沉积环境逐渐演化为远坳陷湖盆的河流沉积环境（河流—冲积平原）以及凹陷盆地冲积扇沉积环境，其水平面具有两次加深—变浅的旋回性变化过程。地层组合序列变化记录了盆地沉积演化的地质历史，反映了一个陆相坳陷盆地初始形成、扩张、萎缩到消亡和一个凹陷盆地的形成、发展和萎缩的叠合过程。长周期基准面下降半旋回晚期出现的煤层具有条带状冲刷减薄现象，在掘进中重点预防厚煤层顶板层状剥落现象；而在长周期基准面上升半旋回与下降半旋回转换处（最大水泛面处）沉积煤层具有分叉、合并现象，在掘进中需要重点预防顶板塌陷现象。

High-resolution sequence stratigraphy and sedimentary environment evolution of Mesozoic in Bulianta coal mine

Based on the data of multiple borehole cores and logging, combined with the regional geological background, the sequence stratigraphy and microfacies of Mesozoic in Bulianta coal mine were divided, and the evolution law of sedimentary environment was summarized. The results show that the Mesozoic in Bulianta coal mine could be divided into 7 long-period base level cycles and 13 medium period base level cycles, which could be compared in the whole mining area. From bottom to top, Jurassic Yan ' an Formation was delta sedimentary facies, Jurassic Zhiluo Formation and Anding Formation was fluvial sedimentary facies, and Cretaceous Zhidan Group was alluvial fan sedimentary facies. From early to late in Mesozoic, the sedimentary environment of Bulianta coal mine had gradually evolved from the delta sedimentary environment of near depression lake basin to the fluvial sedimentary environment （river alluvial plain） of far depression lake basin and the diluvial fan sedimentary facies of depression basin. Its horizontal plane had two deepening-shallowing cyclic changes. The change of stratigraphic assemblage sequence recorded the geological history of sedimentary evolution of the basin, and reflected the superimposition process of initial formation, expansion, shrinkage to extinction of a continental depression basin and the formation, development and shrinkage of depression basin. The coal seam in the late half cycle of long-period base level decline has the phenomenon of strip erosion thinning, which focused on preventing the roof spalling of thick coal seam in tunneling. The sedimentary coal seam at the conversion of ascending and descending half cycles（the maximum flooding surface）of long-term base level has the phenomenon of bifurcation and merger, and it is necessary to focus on preventing roof collapse in tunneling.