贵州晚二叠世含煤地层沉积格局及其构造控制

Sedimentary Patterns and Structural Controls of Late Permian Coal-Bearing Strata in Guizhou, China

贵州省主要含煤地层是上二叠统龙潭组和长兴组,先前研究基本查明了其沉积环境和区域构造背景．在此基础上,结合近年来的勘探成果,进一步就区域构速对含煤地层沉积格局的控制作用进行了探讨.研究表明:晚二叠世期间发育的同沉积断裂对含煤地层沉积格局起着区域性控制作用,形成了“东西分带、南北分区”的沉积与聚煤格局．总体来看,以横贯中部的遵义-惠水NNE向断裂带为界,东部地区海相沉积较为发育且煤层发育极差,西部地区以海陆交互相沉积为主且煤层发育较好;以盘县-六盘水NNE向断裂带为界,西部主要表现陆源区,而东部为沉积区.在此构造背景上,六盘水-瓮安断裂带将贵州中、西部进一步划分为黔北隆起和黔南坳陷2个一级构造单元,2个单元的沉积作用和聚煤特征差异显著．不同断裂带在不同沉积阶段沉降活动的差异性,是导致龙潭早期、龙潭晚期、长兴期沉积格局和聚煤特征有所不同的重要原因．

The major coal-bearing strata in Guizhou, South China, is composed of the late Permian Longtan and Changxing formations whose sedimentary environments and structural setting had been found out in previous researches. In this paper, the controls of the regional structure to the sedimentary patterns of the strata were discussed. The results show that the strata was regionally controlled by the synsedimentary faults within the late Permian, which resulted in the sedimentary and coal-accumulating patterns of the west-east zoning and northsouth sectioning in Guizhou. In general, taking the Zhunyi-Huishui NNE fault zone as a boundary, the marine deposits with poor coal seam were rather developed in the eastern, and the continental-oceanic transitional deposits with better coal seam were dominant in the western. Taking the Panxian-Liupanshui NNE fault zone as a boundary, the land-source area existed mainly in the western, and sedimentary area occurred in the eastern. Based on the structural setting, the central western in Guizhou was further divided into two the first-order structural units, i. e. , the north Guizhou uplift and south Guizhou depression, which were distinctly different in sedimentation and coal accumulation. The diversity of the sedimentary and coal-accumulating patterns among the early Longtan, late sulted from the differential subsidence in various stages. Longtan and Changxing ages was mainly refault zones within the different sedimentary