贵州南华纪-震旦纪沉积大地构造及其对沉积矿产的控制作用

摘要

In early Neoterozoic(>820-720 Ma),South China formed with Yangtze block,Cathaysia Massif and Jiangnan orogen. In late Neoterozoic,Nanhua rift valley developed along Jiangnan orogen of early Neoterozoic in Nanhua period-Sinian period(720-541 Ma),east Guizhou is an important part of Nanhua rift valley. The view of tradition thought that east Guizhou of this valley is NNE,more and more evidences improved that this valley is NEE. The rift valley of Nanhua period in east Guizhou has typical horst and graben structure, it also control the'Datangpo type'manganese deposit distribution. Rift valley went into sedimentation stage after Sinian period, the center migrated to the south of Kaili-Yuping. In Sinian period,Yangtze block and Nanhua rift valley had obvious sedimentary differentiation of phosphorate deposit in shallow sea-carbonate rock and pelite-silicalite. Yangtze block and Nanhua rift valley controlled the distribution of phosphorite deposit of Doushantuo formation,Sinian period of Yangtze block and barite in Laobao formation of Nanhua rift valley. Rich phosphprite developed in the south margin of Yangtze block in the north of Songtao-Guiyang syndepositional fault,barite developed in Tianzhu-Cengong area in where the rift valley sedimented strongly.%新元古代早期(>820 720 Ma),华南由扬子地块、华夏地块和江南造山带3个构造单元组成.新元古代晚期,南华纪-震旦纪(720 541 Ma)沿新元古代早期的江南造山带发育一裂谷盆地-南华裂谷,贵州东部是南华裂谷的重要组成部分.传统认为黔东地区该裂谷盆地为北北东向,越来越多的证据证明该裂谷盆地为北东东向.黔东地区南华纪裂谷盆地具有典型的地堑、地垒结构,并控制着"大塘坡式"锰矿的分布.震旦纪之后,裂谷盆地处于沉降阶段,沉降中心向南迁移到凯里-玉屏一线.震旦纪时期,扬子地块和南华裂谷存在明显的滨浅海磷矿-碳酸盐岩和深水泥质岩-硅质岩的沉积分异.扬子地块和南华裂谷控制着扬子地块震旦系陡山沱组磷矿和南华裂谷老堡组重晶石等沉积矿产的分布.富磷矿位于松桃-贵阳同沉积断裂以北的扬子地块南缘,重晶石矿发育于裂谷盆地强烈沉降区的天柱-岑巩一带.