桂西南上泥盆统含锰岩系形成古海水深度条件分析  

Depth of Ancient Sea Related with Formation of the upper Devonian Mn-bearing Rock Series in Southwestern Guangxi Province

作　　者：秦元奎[1] 徐柏安[1] 姚敬劬[1] 

机构地区：[1]中南冶金地质研究所,宜昌443003

出　　处：《地质与勘探》2010年第2期277-284,共8页Geology and Exploration

基　　金：国家"十一五"科技支撑计划项目桂西南-滇东南大型锰矿勘查与评价研究课题(编号2006BA01A12-4)的资助

摘　　要：桂西南上泥盆统含锰岩系是我国沉积锰矿最主要的赋矿岩系之一,岩系形成于台间海槽环境。但是对台间海槽的海水深度历来有不同的认识。本文在如下方面作了进一步的研究:分析了产于含锰岩系榴江组和五指山组中古生物化石种属的特征及其与古生物生存环境的关系;鉴定了沉积物中可作为形成水深标志的特殊的矿物和岩石结构;测定了岩系中Ni、V、Cr等元素的含量,并据其比值特征推断了沉积物形成时的氧化还原条件。研究结果认为:晚泥盆世产于台沟海槽的含锰岩系形成于浅海环境,古海水深度范围可能为50～200m,一般水深0～150m。The Upper Devonian Mn-bearing series of south west Guangxi is the most important formation in China.Although it is commonly accepted that this series formed in a sea trough setting of between platforms,the ancient sea depth at which the Mn-bearing sediments settled is controversial.In this paper we present features of fossils species from Liujing and Wuzhishang formation and relationship between distribution of Living beings phylum and environment.We identify particular minerals and rock structures as the indicator of ancient sea depth.We analyze the content of V,Ni,and Cr and determine the oxidize-reduce condition in sedimentation.According to the results,we suggest that the Mn-bearing series formed in a shallow sea environment of interplatform channel and the possible range of ancient sea depth is 50-200 m,and the general depth is 80-150 m.

关 键 词：桂西南 上泥盆统 含锰岩系 古水深 

分 类 号：P618.32[天文地球—矿床学]