云南省香格里拉县甭哥碱性杂岩体岩石地球化学特征及其地质意义

发布时间：2018-03-13 00:21

本文选题：甭哥碱性杂岩体　切入点：多期岩浆作用　出处：《岩石学报》2017年02期 　论文类型：期刊论文

【摘要】：云南省香格里拉地区发育一套以甭哥碱性杂岩体为代表的富碱高钾岩浆岩。该岩体SiO_2变化范围较宽,高FeO~T和碱质,低Al_2O_3、MgO和CaO;富集LILE和LREE,相对亏损HFSE并显著亏损Cr、Co、Ni等过渡族元素,同时还具有从弱负异常至强正异常的δEu及δCe,表现出埃达克质与岛弧型火山岩双重特征。岩石地球化学研究表明,甭哥岩体并非单一岩浆经简单结晶分异而来,其岩浆来源具有多样性与多期性,它们主要代表了晚三叠印支期俯冲洋片和地幔楔与下地壳部分熔融及新生代含金云母相的交代富集地幔低程度部分熔融的岩浆作用。其形成和演化大致经历了晚印支期初始岩浆形成和燕山期后续岩浆逐步叠加及新生代喜山期岩浆侵位三个阶段,在整个岩浆作用过程中,伴随有地幔流体交代作用及由此引发的壳幔物质混染现象。而与甭哥碱性杂岩体有关的金成矿作用主要受制于该区多阶段岩浆与含矿地幔流体的相互作用及地幔流体交代叠加混染作用,其金成矿的富矿体可能定位于深部,据此提出甭哥碱性杂岩体具有深部成矿的勘探开发远景。
[Abstract]:In Shangri-la area of Yunnan Province, there is a set of alkali rich and high potassium magmatic rocks, represented by the Boko alkaline complex, which have a wide range of SiO_2 variations, high FeO~T and alkali quality, low Al2O3, MgO and Cao, enriched in LILE and LREE, relatively depleted in HFSE, and significantly depleted in transitional elements such as Cr-Co-Ni, etc. At the same time, 未 EU and 未 Cefrom weak negative anomaly to strong positive anomaly show dual characteristics of adakitic and island-arc volcanic rocks. Its magma sources are diverse and multiphase. They mainly represent the magmatism of the subduction ocean plate and mantle wedge in the late Indosinian epoch and the partial melting of the lower crust and the metasomatic enrichment mantle of the Cenozoic phlogopite facies. The three stages of Indosinian initial magmatic formation and Yanshanian successive magma superposition and Cenozoic Himalayan magmatic emplacement are as follows. During the whole process of magmatism, Along with the mantle fluid metasomatism and the crust and mantle material mixing phenomenon, the gold mineralization related to the Bago alkaline complex is mainly restricted by the interaction between the multi-stage magma and the ore-bearing mantle fluid and the mantle. Fluid metasomatism superposition dyeing, The ore-rich bodies may be located in the deep, so it is suggested that the Bago alkaline complex has the prospect of deep metallogenic exploration and development.
【作者单位】：成都理工大学地球科学学院;四川省冶金地质勘查局成都地质调查所;
【基金】：中国地质调查局地调项目(1212011120587) 国土资源部构造成矿成藏重点实验室(成都理工大学) 国家自然科学基金项目(41403025)联合资助
【分类号】：P588.15

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