湘中南华系大塘坡组锰矿地球化学特征及其意义  

Geochemical Characteristics and Significance of Manganese Deposits in Datangpo Formation,Central Hunan Province

作　　者：刘虎 施磊 叶锋 曹景良[1] 陈艳[2] 吴继兵 王哲 王娟[1] LIU Hu;SHI Lei;YE Feng;CAO Jingliang;CHEN Yan;WU Jibing;WANG Zhe;WANG Juan(Hunan Geological Exploration Institute of China Metallurgical Geology Bureau,Changsha,Hunan 410016;Guangxi Fourth Geological Team,Nanning,Guangxi 530031)

机构地区：[1]中国冶金地质总局湖南地质勘查院,湖南长沙410016 [2]广西第四地质队,广西南宁530031

出　　处：《地质与勘探》2019年第S01期383-393,共11页Geology and Exploration

基　　金：中国地质调查局“湘西-滇东地区矿产地质调查”项目(编号:DD20160032)资助。

摘　　要：湘中湘潭盆地大塘坡组锰矿是湖南重要的锰矿基地。盆地内发育一组NNE向同沉积断裂,形成了一系列凹陷带(断陷槽),控制了沉积岩相的分布,锰矿主要产于盆地凹陷带的黑色页岩夹碳酸锰矿微相内。矿石中Co、Zn、Pb、Mo和Ba等元素丰度较高,Co/Ni、SiO_(2)/Al_(2)O_(3)、(Fe+Mn)/Ti、Al/(Fe+Mn+Al)比值以及Co/Zn-(Cu+Ni+Co)和Fe-Mn-(Cu+Ni+Co)图解都揭示锰矿成矿过程中有海底热水的参与;稀土元素分布模式、Ce、Eu异常表示锰矿形成于被动大陆边缘环境,并具有热水沉积特征;碳同位素结果显示出富集碳的轻同位素的特征,反映了湘中地区锰矿中碳同位素热水沉积的特征;氧同位素计算古温度为湘中地区锰矿的低温热水沉积成因提供了有利的佐证。The manganese deposit in Datang formation of Xiangtan basin in central Hunan is an important manganese ore base in Hunan.A group of NNE trending synsedimentary faults developed in the basin,forming a series of depression belts(fault troughs),controlling the distribution of sedimentary facies.Manganese deposits mainly occur in the black shale intercalated with manganese carbonate microfacies in the basin depression belt.Co,Zn,Pb,Mo and Ba are abundant in the ores.Co/Ni,SiO_(2)/Al_(2)O_(3),(Fe+Mn)/Ti,Al/(Fe+Mn+Al)ratios and Co/Zn-(Cu+Ni+Co)and Fe-Mn-(Cu+Ni+Co)diagrams reveal the participation of seafloor hydrothermal water in the process of manganese mineralization.The distribution pattern of rare earth elements,Ce and Eu anomalies indicate that manganese ore was formed on the passive continental margin.The results of carbon isotope analysis show the characteristics of light isotope enrichment,which reflects the characteristics of carbon isotope hydrothermal sedimentation in manganese deposits in central Hunan.The paleotemperature calculated by oxygen isotope provides favorable evidence for the genesis of low temperature hydrothermal sedimentation of manganese deposits in central Hunan.

关 键 词：地球化学 南华纪 地质特征 锰矿 湖南省 

分 类 号：P618[天文地球—矿床学]