摘要
湘西-黔东地区下寒武统发育完整,是一套从黑色岩系到碳酸盐岩的沉积序列,代表早寒武世复杂的古地理变迁。纵向上,下寒武统组成一个二级层序,可以进一步划分为5个三级层序,构成总体向上变浅的沉积相序列,同时反映了缓坡型碳酸盐岩台地的生长发育过程,铅锌矿赋存于第四层序高水位体系域中;空间上从北西至南东发育从局限台地、浅滩和微生物(藻)丘相、陆棚相等沉积。岩相古地理对层控铅锌矿具有明显的控制作用,主要分布于台地边缘藻丘和浅滩相与局限台地潮下过渡部位。研究表明牛蹄塘组黑色碳质页岩是铅锌矿源层,清虚洞组灰岩是主要容矿层,其中浊积岩、藻丘体、砾(粒)屑灰岩构成一个完整的铅锌控矿序列。
In the Western Hunan and Eastern Guizhou Provinces, the Lower Cambrian is well developed and marked by sedimentary succession from black shale to carbonate rocks. Vertically, the stratigraphic succession constitutes a second-order sequence that can be further subdivided into five third-order sequences, and that makes up of a larger scale upward-shoaling succession of sedimentary facies and demonstrates a growth process of the ramp carbonate platform. Horizontally, the principal lithofacies palaeogeographic units in the study area, i. e. carbonate tidal flat, subtidal facies of restricted platform and platform marginal bioherm （or bank） facies as well as basin facies from the northern to the southern have been described. All of them demonstrate a complicated palaeogeographic background. The stratabound lead-zinc deposits distributing between platform marginal facies and subtidal facies of restricted carbonate platform were dominated by the lithofacies palaeogeographic framework. The black shale of the Niutitang Formation is source bed for the lead-zinc mineralization and the Qingxudong Formation is the host rock （reservoir bed）. The assemblage that made up of turbidite and algal bioherm （reef） and rudstone is a well developed succession for the lead-zinc deposits controlling.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2012年第1期111-117,共7页
Geotectonica et Metallogenia
基金
中国地质调查局"上扬子铅锌矿床与岩相古地理关系研究"(1212011121100)
"上扬子地块及其周缘铅锌多金属矿综合评价"(1212010813068)
"湘西-鄂西地区铅锌多金属矿勘查选区研究"(1212010632005)成果之一
关键词
铅锌矿制约
沉积序列
早寒武世
湘西-黔东地区
lead-zinc deposit
sedimentary sequence
Lower Cambrian
Western Hunan
Eastern Guizhou
