云南东川铜矿带碳、氧同位素特征及成矿机制讨论  

Carbon and oxygen isotopic characteristics and metallogenic mechanism of Dongchuan copper belt in Yunnan Province

作　　者：曾瑞垠 王蒙 王幻 祝新友 张雄 王迪恒 ZENG Ruiyin;WANG Meng;WANG Huan;ZHU Xinyou;ZHANG Xiong;WANG Diheng(Sinotech Minerals Exploration Co.,Ltd.,Beijing 100012,China;Sino-Zijin Resouces Ltd.,Beijing 100012,China;No.8 Institute of Geology and Mineral Resources Exploration of Shandong Province,Rizhao 276800,Shandong,China;Beijing Institute of Geology For Mineral Resources Co.,Ltd.,Beijing 100012,China)

机构地区：[1]中色地科矿产勘查股份有限公司,北京100012 [2]中色紫金地质勘查(北京)有限责任公司,北京100012 [3]山东省地质矿产勘查开发局第八地质大队,山东日照276800 [4]北京矿产地质研究院有限责任公司,北京100012

出　　处：《矿产勘查》2023年第9期1595-1603,共9页Mineral Exploration

基　　金：中国铜业有限公司重点科技计划项目“云南东川铜矿成矿规律与成矿预测(2018K01)”资助。

摘　　要：东川铜矿带地处云南东川盆地,属于沉积岩容矿层状铜矿带,发育有稀矿山式铁铜矿体、东川式铜矿体、桃园式铜矿体等多类型铜矿体。为探讨东川铜矿带的成矿机制,本文通过对东川铜矿带各类型矿体的碳、氧同位素分析,结合前人研究成果,发现相对于赋矿白云岩,稀矿山式、东川式、桃园式铜矿体的白云石δ13C值呈降低的趋势,东川式铜矿体的包裹体δ13C值为-16.40‰~-0.20‰,桃园式铜矿体的包裹体δ13C值为-18.40‰~-4.20‰,包裹体中的δ13C值呈现明显的低值。碳、氧同位素特征说明成矿流体的碳源主要来自于海相碳酸盐的溶解作用,其次来自于有机质的氧化作用和脱羟基作用,有机质亦参与了成矿作用。含矿卤水运移到具还原性质的落雪组白云岩和黑山组炭质板岩中,与含有机质地层和含有机质流体发生氧化还原反应,形成多层位的层控铜矿床,东川铜矿带成矿机制为盆地卤水交代成矿。Dongchuan copper belt is located in Dongchuan Basin,Yunnan Province.It belongs to the layered copper belt containing deposits in sedimentary rocks.There are many types of iron copper bodies such as thin mine type,Dongchuan type,Taoyuan type,etc.In order to explore the metallogenic mechanism of Dongchuan copper belt,this paper analyzes the carbon and oxygen isotopes of various types of orebodies in Dongchuan copper belt and integrates the previous research results.It is found that theδ13C value of dolomite of the Xikuangshan type,Dongchuan type and Taoyuan type copper orebodys show a decreasing trend compared with the ore-bearing dolomite.Theδ13C values of the inclusions of Dongchuan type copper bodies are-16.40‰to-0.20‰,and that of Taoyuan type copper bodies are-18.40‰to-4.20‰,and theδ13C values of the inclusions are obviously low.The characteristics of carbon and oxygen isotopes indicate that the carbon source of ore-forming fluid mainly comes from the dissolution of marine carbonate,followed by the oxidation and dehydroxylation of organic matter,which is involved in the mineralization.Ore-bearing brine migrated into the reducing dolomite of Louxue Formation and the carbonaceous slate of Heishan Formation,and redox reaction occurred with organic strata and organic fluids to form multilayer stratified copper deposits.The mineralization mechanism of Dongchuan copper belt is brine metasomatism mineralization in the basin.

关 键 词：东川铜矿 碳同位素 氧同位素 有机质 成矿机制 

分 类 号：D42[政治法律—政治学]