湘西-黔东地区寒武系都匀阶清虚洞期岩相古地理与铅锌成矿关系研究  

Lithofacies Palaeogeography of the Qingxudong Epoch,Duyun Stage,Cambrian Period and its Relationship to Lead-Zinc Deposits in Western Hunan and Eastern Guizhou Province

作　　者：汤朝阳[1] 邓峰[2] 李堃[1] 赵武强[1] 金世超[1] 

机构地区：[1]中国地质调查局武汉地质调查中心,湖北武汉430223 [2]河南省地质矿产勘查开发局第一地质勘查院,河南郑州450007

出　　处：《地质与勘探》2013年第1期19-27,共9页Geology and Exploration

基　　金：中国地质调查局项目(编号1212011121100和1212010632005)资助

摘　　要：依据地层记录中的两种相变面和两种穿时性,结合上扬子地区寒武系十余条代表性剖面的沉积特征及其横向展布规律,应用等时面优势相成图方法编制了寒武系都匀阶清虚洞期岩相古地理图。区内古地理格局具有西高东低、北浅南深(水深)的特点,沉积自北西向南东超覆,层位逐渐抬高穿时;岩性、厚度、颜色和沉积相类型上的差异是统一沉积背景下沉积物相变、穿时的结果。清虚洞组由灰岩段和白云岩段组成,以发育缓坡型碳酸盐台地为特征,纵向上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台地的生长发育过程;横向上从北西至南东发育从混积潮坪相、浅缓坡相、中缓坡相、深缓坡相和陆棚-盆地等沉积。岩相古地理对层控铅锌矿具有明显的控制作用,主要分布于中缓坡相藻灰岩微晶丘中,浊积岩、微晶丘、砾(粒)屑灰岩构成一完整的铅锌控矿序列。Based on two types of facies-changing surfaces and two types of diachrononisrns in stratigraphic records, and combining with the sedimenta- ry characteristics and lateral facies distribution of more than ten typical Cambrian profiles in the upper Yangtze region, the lithofacies palaeogeography of the Qingxudong epoch, Duyun stage, Cambrian Period has been studied with the isochronal dominant facies method and a stratigraphic map is prepared. The paleogeography in the study area is characterized by high in the west and low in the east, deep water in the south and shallow water in the north. The sediments overlapped from NW to SE, and exhibit diachrononism with increasing depth. The differences of the lithology, thickness, color and sedimentary facies are due to the sedimentary facies change and diachrononism. Vertically, the stratigraphic succession from the dolomite member and the limestone member of the Qingxudong Formation makes up of a large-scale upward-shoaling sedimentary facies succession and demonstrates a growth process of a ramp carbonate platform. Horizontally, the principal lithofacies palaeogeographic units in the upper Yangtze region, i. e. , carbonate tidal fiat, shallow ramp fa- cies, middle ramp facies, deep ramp facies, shallow shelf facie, and deep shelf facies as well as basin facies from the northern to the southern have been described. The lithofacics palaeography exerts a key control on the stratabound-typc lead-zinc deposits, which are distributed in the middle- and shallow ramp facies of the restricted platform, and the assemblage making up of turbidite and micrite mounds （ algal bioherm） and rudstone is a well developed succession for lead-zinc deposits.

关 键 词：铅锌成矿岩相古地理都匀阶寒武系 湘西-黔东地区 

分 类 号：P618[天文地球—矿床学]