摘要
富碱斑岩因其产出构造环境独特、岩石类型特殊,并常与铜多金属矿床密切相关,而受到广泛关注。笔者等在回顾相关研究进展的基础上,通过岩石成因和构造环境、岩浆性质和岩浆源区等方面的综合研究,探讨了金沙江—红河富碱斑岩成矿带富碱岩浆成矿作用及成岩成矿机制。系统的矿床地质、年代学、地球化学等研究表明:①金沙江—红河富碱斑岩成矿带内成岩成矿作用集中于43~32 Ma,成矿富碱斑岩系始新世—渐新世I型钾玄质花岗斑岩,是印—亚大陆后碰撞背景下大陆内部大型走滑和伸展等动力过程诱导的岩浆活动产物,金沙江和哀牢山—红河断裂的差异走滑运动可能控制了成矿带差异性成岩成矿事件;②成矿带北段以Cu—Mo为主的成矿富碱斑岩源自新元古代下地壳的部分熔融,且源区有富集地幔和亏损地幔物质的加入,而南段以Cu—Au或Cu(—Mo—Au)为主的成矿富碱斑岩源自具有不同程度富集地幔物质加入的新生下地壳的部分熔融;③带内以Cu为主的斑岩—矽卡岩型矿床中成矿富碱斑岩的氧逸度(ΔFMQ)与矿床规模具有正相关性。除受氧逸度控制外,源区高K2O含量有利于斑岩—矽卡岩型Au矿床的形成。该研究对金沙江—红河富碱斑岩成矿带乃至同类矿床研究和找矿勘查具有理论和实际意义。
Objectives:Alkali-rich porphyry has attracted extensive attention because of its unique tectonic setting,special rock type and close relationship with copper polymetallic deposits.By reviewing the related research progress of alkali-rich porphyry,this paper focuses on discussing the mineralization of alkali-rich magma and its petrogenetic and metallogenic mechanism in the Jinsha River—Honghe River alkali-rich porphyry metallogenic belt,from the comprehensive study of petrogenesis and tectonic setting,magmatic properties and source control of mineralization,etc.Systematic studies on the geology,chronology and geochemistry of ore deposits show that:①the magmatic emplacement and mineralization ages of porphyry—skarn deposits in the Jinsha River—Honghe River alkali-rich porphyry metallogenic belt are concentrated in the range of 43~32 Ma.The ore-bearing alkali-rich porphyries belong to Eocene—Oligocene I-type shoshonitic granite porphyries,which were products of intracontinental magmatic activity induced by geodynamic processes such as large-scale strike-slip and extension in a post-collisional setting.The divergently magmatic and metallogenic events in the belt may be controlled by the divergent strike-slip movements between the Jinsha River and Ailao Mountains—Honghe River strike-slip faulting resulted from the Indo—Asian collision;②the ore-bearing alkali-rich porphyries associated with Cu—Mo mineralization in northern section of the metallogenic belt were probably derived from the partial melting of a Neoproterozoic lower crust with the addition of enriched and depleted mantle-derived magmas.However,the orebearing alkali-rich porphyries associated with Cu—Au or Cu(—Mo—Au)mineralization in southern section of the metallogenic belt were probably derived from the partial melting of juvenile lower crust with variable contributions from enriched mantle-derived components;and③there is a positive relationship between the oxygen fugacity(ΔFMQ)and deposit size(metal tonnage)for porphyry—skarn C
作者
杨航
王蝶
吴鹏
王峰
陈福川
YANG Hang;WANG Die;WU Peng;WANG Feng;CHEN Fuchuan(Faculty of Land Resource Engineering,Kunming University of Science and Technology,Kunming,650093;Southwest of Geological Survey,Geological Survey Center for Non-ferrous Mineral Resources,Kunming,650093;Yunnan Metallurgy Resources Exploration Co.,Ltd.,Kunming,651100)
出处
《地质论评》
CAS
CSCD
北大核心
2023年第5期1669-1693,共25页
Geological Review
基金
国家自然科学基金资助项目(编号:41102049,41963003)
云南省“万人计划”青年拔尖人才专项(编号:YNWR-QNBJ-2018-272)
云南省矿产资源预测评价工程实验室(2010)
云南省地质过程与矿产资源创新团队(2012)资助项目的成果。
