南大西洋15°S热液区玄武岩中熔融包裹体组成及意义  

The significances and compositions of melt inclusions in the basalt from South Atlantic 15°S hydrothermal field

作　　者：唐鑫[1,2] 杨耀民 王国芝[2] 张海桃[3] 范蕾[2] 许鹏[2] 朱志伟[3] 

机构地区：[1]国家深海基地管理中心,山东青岛266237 [2]成都理工大学地球科学学院,成都610059 [3]国家海洋局第一海洋研究所,山东青岛266061

出　　处：《成都理工大学学报（自然科学版）》2016年第3期362-371,共10页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：中国大洋协会"十二五"重大项目(DY125-12-R-01);国家自然科学基金项目(41273060)

摘　　要：熔融包裹体中的硅酸盐子矿物、金属相和流体相可以动态地反映岩浆演化过程中岩浆的成分变化和金属成矿物质从熔浆中出熔分离的过程。本文选取南大西洋中脊15°S(SMAR15°S)热液区玄武岩斜长石熔融包裹体作为研究对象,通过扫描电镜能谱分析和激光拉曼分析,揭示熔融包裹体中熔体相的成分和金属矿物的种类,探讨岩浆作用对成矿的贡献。研究表明,斜长石熔融包裹体中存在黄铜矿、黄铁矿、磁铁矿和铬铁矿等金属子矿物,它们随脱气作用从岩浆中分离并进入岩浆流体相中冷凝结晶。熔融包裹体中金属子矿物与母岩无明显蚀变,共同指示岩浆流体对SMAR15°S热液区块状硫化物的形成可能具有一定贡献。SMAR15°S热液区热液硫化物可能存在岩浆来源。The characteristics of silicate minerals, metals and fluid phase in the melt inclusions contain the information on composition changes of magma and separation process of metal ore-forming materials in the process of magma evolution. Therefore, melt inclusions in the basalt plagioclases from the 15°S hydrothermal field of the South Middle Atlantic Ridge （SMAR15°S） are selected as research object so as to study the contribution of the magmatism to the mineralization. Analyses of scanning electron microscopy, energy spectrometer and laser Raman spectroscopy reveal that some metal minerals such as chalcopyrite, pyrite, magnetite and chromite exist in the melt inclusions. It is considered that these metal minerals are precipitated in the melt inclusions from the magma by the degassing processes. The metal minerals both in the melt inclusions and in the low alteration host rocks indicate that the magmatic fluids in the SMAR15°S hydrothermal field make contribution to the formation of hydrothermal sulfides and the magmatic fluid is one of the resources for the hydrothermal sulfide in the SMAR15°S hydrothermal field.

关 键 词：南大西洋中脊 SMAR15°S热液区 玄武岩 熔融包裹体 

分 类 号：P588.145[天文地球—岩石学]