黔西北晚二叠世含煤岩系高分辨率层序地层与聚煤模式研究

在高分辨层序地层学基本理论指导下,结合研究区岩心数据、测井等资料对黔西北晚二叠世含煤岩系划分出三个层序组,在此基础上研究了黔西北晚二叠世的聚煤模式。分析认为:研究区晚二叠世厚煤层的形成与分布直接受控于古沉积环境,水城、纳雍一带聚煤中心的三角洲沉积组合利于厚煤层的形成;聚煤中心的迁移受控于沉积盆地旋转引起的旋转旋回沉积机制;龙潭期—长兴期持续海进是研究区晚二叠世含煤岩系沉积期,尤其是晚二叠世沉积盆地顺时针方向的旋转导致可容纳空间变化的非均一性,致使聚煤中心发生逆时针方向的北迁和回迁。

A Study on Late Permian Coal-bearing Strata High Resolution Sequence Stratigraphy and Coal Accumulation Pattern in Northwestern Guizhou

Under the guidance of high resolution sequence stratigraphy basic principles, combined with study area rock core, well log-ging data, partitioned the late Permian coal-bearing strata into three sequence groups, and then studied the coal accumulation pattern in the area on this basis. The analysis considered that the formation and distribution of late Permian thick coal seams are directly con-trolled by paleosedimentary environment. Delta sedimentary association of coal accumulation centers in Shuicheng-Nayong district is advantageous to form thick coal seams. The migration of coal accumulation centers are controlled by the rotational cyclic sedimentation mechanism caused by sedimentary basin rotation. The durative transgression during Longtan-Changxing period coal-bearing strata sed-imentary stage, especially sedimentary basin clockwise rotation was the causation of accommodation space variation heterogeneity in the study area, and caused counter-clockwise northward migration and moved back of coal accumulation center.