二叠纪贵州遵义次级裂谷盆地结构及其对锰矿的控制作用*

遵义锰矿不仅是在贵州发现最早的具工业价值的锰矿床,而且也是中国重要的锰资源基地之一。根据详细的二叠系茅口组—龙潭组地层划分,认为黔北裂陷遵义次级裂谷盆地由3个Ⅲ级断陷盆地和2个Ⅲ级隆起组成,至少包括13个Ⅳ级断陷盆地。3个Ⅲ级断陷盆地的演化,分别控制了铜锣井—深溪、转龙庙—谢家坝、张家湾—兴隆、和尚场—五龙溪锰矿成矿亚带的形成,其中铜锣井—深溪锰矿成矿亚带位于遵义次级裂谷盆地的中心,成矿作用强烈,已发现有铜锣井、深溪、永安3个大型锰矿床。Ⅳ级断陷盆地的发育,控制了研究区内各个锰矿床的形成。研究区内同沉积断层发育,已辨别出的14条同沉积断层为深部含硅、锰质气液的上升通道,是遵义二叠系锰矿形成的关键。综上,遵义次级裂谷盆地的发育和演化,对该地区锰矿沉积具有重要的控制作用。该研究成果对寻找遵义锰矿隐伏矿床、指导整装勘查具有重要的意义。

Structure of Zunyi rift basin in Guizhou Province during the Permian and its controlling on manganese deposits

As the earliest discovered manganese mine with industrial value in Guizhou Province,Zunyi manganese deposit is one of the important manganese resource bases in China. According to the detailed division of the Permian Maokou-Longtan Formations,the Zunyi secondary rift basin is considered to be composed of three 3^rd-order faulted basins and two 3^rd-order uplifts,which could be classified into at least 13 4th-order faulted basins. The 3^rd-order faulted basins controlled the formation of the Tongluojing-Shenxi,Zhuanlongmiao-Xiejiaba,Zhangjiawan-Xinglong,and Heshangchang-Wulongxi manganese sub-belts. The Tongluojing-Shenxi manganese sub-belt is the center of the Zunyi rift basin with strong manganese mineralization,forming three large manganese beds in Tongjing,Shenxi,and Yongan. The 4th-order faulted basins controlled the formation of various manganese beds in the study area. Moreover,14 synsedimentary faults have been identified,which are believed to be the ascending channel of the deep fluids rich in silicon and manganese gas and play a key role on the formation of Zunyi Permian manganese deposit. Therefore,the formation of Zunyi rift basin has a significant controlling on the manganese deposit. Results of this research are of great significance for searching hidden deposits and guiding the full-scale exploration of Zuiyi Manganese deposit.