海洋地质前沿2025，Vol.41Issue(6)：25-39,15.DOI:10.16028/j.1009-2722.2024.093
马里亚纳弧NW Eifuku热液区岩石中黄铁矿的地球化学特征
Geochemical characteristics of pyrite from rocks in the NW Eifuku hydrothermal area of the Mariana Arc
摘要
Abstract
A slightly altered volcanic rock sample and the bearing pyrite near NW Eifuku hydrothermal vent in the northern part of the Mariana Arc were selected.The major elements of the sample were analyzed,the olivine and pyrite were observed by electronic microprobe,and the S-isotope of pyrite was investigated.In addition,the geochemical characteristics,origination,and microbial mineralization of the pyrite were scrutinized.Results show that the sample is basaltic andesite in lithology,and contains four types of pyrite in occurrence,namely pyrite in altered porphyritic crystals,in porphyritic fissure,in matrix,and in air bubbles.The last three types of pyrite are idiomorphic or semi-idiomorphic,and are the products of early hydrothermal activity,while the pyrite in altered porphyritic crystals are allotriomorphic and colloidal and the S/Fe ratio is greater than those of the other three types,indicating their low temperature origin due to temperature drop caused by the mixing of hydrothermal flu-ids with seawater.The δ34 S values of the four types of pyrite are negative(-6.58‰～-19.60‰),and some of the idiomorphic pyrite have iron oxide layer edges,indicating that those pyrites may had been affected by microbial action during its formation.In particular,the Co and Ni contents of pyrite in altered peridotite is significantly greater than those of other types of pyrite,indicating the influence by the change in hydrothermal fluid composi-tion before and after alteration and the temperature drop due to hydrothermal fluid mixture with seawater,result-ing in the easier entry of elements into the lattice of pyrite.The difference in the chemical element content between the core and the rim of pyrite might be caused by microbial action,while the effect of olivine alteration on the element content of pyrite was relatively small.关键词
马里亚纳岛弧热液喷口/黄铁矿/微量元素/微生物成矿Key words
Mariana Arc hydrothermal vent/pyrite/trace element/microbial mineralization分类
海洋科学引用本文复制引用
刘锦风,曾志刚,王晓媛,曾志斌,杨小双,齐海燕..马里亚纳弧NW Eifuku热液区岩石中黄铁矿的地球化学特征[J].海洋地质前沿,2025,41(6):25-39,15.基金项目
国家自然科学基金"深海界面过程和化能生态系统"(42221005),"西太平洋俯冲体系中岩浆活动及其对热液物质供给的制约"(91958213),"冲绳海槽与马里亚纳海槽的热液烟囱体特征及其对流体演化的指示"(42330409) （42221005）
中国科学院战略性先导科技专项子课题"热液/冷泉区岩浆物质贡献与流体化学过程"(XDB42020402) （XDB42020402）
国家重点基础研究发展计划(973计划)项目"典型弧后盆地热液活动及其成矿机理"(2013CB429700) （973计划）
泰山学者工程(ts201511061) （ts201511061）
