新疆阿尔泰吉伯特铁矿床包裹体特征研究  

Inclusions study of Jibote iron deposit in the Chinese Altay orogenic belt： Evidence of magmatic in origin

作　　者：王雯[1] 柴凤梅[1] 王海培 杨俊杰[1] 李强[3] 谷高灵[4] 

机构地区：[1]新疆大学新疆中亚造山带大陆动力学与成矿预测实验室,乌鲁木齐830049 [2]新疆维吾尔自治区地质矿产研究所,乌鲁木齐830000 [3]中国地质科学院矿产资源研究所、国土资源部成矿作用与资源评价重点实验室,北京100037 [4]新疆维吾尔自治区地质矿产勘查开发局第四地质大队,新疆阿勒泰836500

出　　处：《地质科学》2017年第2期571-591,共21页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家重点基础研究发展计划“973”项目（编号：2012CB416803）资助;致谢感谢审稿老师和编辑部对本文的意见及建议.野外工作中得到八钢矿业公司的帮助,电子探针实验得到桂林理工大学廖宝丽老师,谢兰芳老师,胡轶同学等的悉心指导和帮助,拉曼测试实验得到中国地质科学院矿产资源研究所熊欣老师的支持和帮助.在此一并致以衷心的感谢.

摘　　要：吉伯特铁矿是新疆阿勒泰地区产于泥盆纪海相火山岩中的小型矿床。本文对吉伯特铁矿床的包裹体开展了研究，识别了熔体包裹体、熔体-流体包裹体以及富晶体的流体包裹体，并对其进行了初步的显微测温、激光拉曼光谱和电子探针等研究。熔体包裹体中含有富si玻璃质、贫Si富Fe熔体、石英、萤石、方解石、磁铁矿等多种成分，它们分别组成不同的包裹体组合。熔体包裹体、熔体-流体包裹体和流体包裹体的存在表明它们被捕获时是一种熔体与流体共存的不混溶状态，这充分说明了吉伯特铁矿床的形成与岩浆熔体、岩浆-热液过渡性流体有直接的成因联系。吉伯特铁矿床中Fe的矿化是一个熔体相逐渐减少，流体相逐渐增加的连续演化过程，它受岩浆作用、岩浆-热液过渡性流体以及矽卡岩作用的共同制约。The Jibote iron deposit is a typical example of iron deposit hosted in submarine volcanic- sedimentary assemblages and located in the Maizi volcano-sedimentary basin in the southern margin of the Chinese Altay orogenic belt （AOB）. The ore bodies are interbedded with the Upper Silurian to Lower Devonian metamorphosed volcanic-sedimentary rocks and display same distortion as wall rocks, which is always associated with intensely skarn alteration. In this research, detailed inclusion studies are carried out on skarn minerals （garnet, diopside and epidote）, quartz and calcite. Abundant inclusions have been observed in garnets including melt inclusions, fluid-meh inclusions and fluid inclusions, while fluid inclusions are only occurred in other minerals. These inclusions were studied using microthermometry, laser Raman spectroscopy and EMPA. The coexistence of melt inclusions with simultaneously trapped fluid- melt inclusions and fluid inclusions suggests immiscibility between silicate melt and hydrothermal fluid （magmatic fluids exsolved）. Melt inclusions contain abundant Fe-rich melt and silica-rich glasses, displaying strong evidence for melt immiscibility which plays a key role in the mineralization. Quartz, fluorite, magnetite and calcite occur at various inclusions and as solid in garnet suggest they are formed by crystallization fractionation from magma melt. Laser Raman experiments reveal H2O as the dominant volatile compounds in the melt inclusions in garnet and CO2 in fluid inclusions in quartz. Inclusions features support a magmatic origin for the Jibote iron deposit and magmatism, magmatic hydrothermal fluids and skarn alteration constraint on metallic ore formation.

关 键 词：熔体包裹体 熔体-流体包裹体 岩浆-热液流体 吉伯特铁矿床阿尔泰 

分 类 号：P618.31[天文地球—矿床学]