东太平洋海隆热液活动及多金属硫化物资源潜力研究进展  

Seafloor Hydrothermal Activity and Polymetallic Sulfide Resources Potential in the East Pacific Rise

作　　者：曾志刚[1] 张维[1] 荣坤波 王晓媛[1] 陈帅[1] 崔路凯 江书龙 齐海燕[1] 

机构地区：[1]中国科学院海洋研究所,山东青岛266071

出　　处：《矿物岩石地球化学通报》2015年第5期938-946,884,共9页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家大洋重大专项课题(DY125-12-R-02);国家重点基础研究发展计划项目(2013CB429700);国家自然科学基金项目(40830849;41325021);山东省自然科学杰出青年基金项目(JQ200913)

摘　　要：本文综述了中国在东太平洋海隆（East Pacific rise,EPR）及其邻域的热液活动及多金属硫化物资源调查研究工作。近12年来,通过对EPR 13°N和1°-2°S多金属硫化物、Fe-Si-Mn羟基氧化物、热液柱、含金属沉积物和玄武岩进行研究,以及对EPR 13°N附近多金属硫化物资源潜力的初步分析。揭示了多金属硫化物的矿物组成特征及其与元素、同位素组成之间的关系;认识到热液柱颗粒物的快速沉淀导致了EPR 13°N附近Fe-Si-Mn羟基氧化物中REE含量较低和Mn含量偏高;指出了EPR 13°N附近可能存在新的热液活动区,并提出新的热液柱温度异常值计算方法;将EPR 13°N附近玄武岩中斜长石微斑晶和玄武质玻璃边缘的化学蚀变分别划分为5种和4种类型;初步论证EPR 1°-2°S附近的玄武岩是E-MORB和N-MORB两个源区的岩浆以不同比例混合形成的,且区内玄武岩中富集组分有可能来源于Galpagos扩张中心附近的热点源岩浆;提出根据多金属硫化物丘状堆积体或喷口群的形态进行储量估算,给出了EPR 13°N附近多金属硫化物堆积体储量的保守值（〉2000万t）。在此基础上,进一步明晰了未来在东太平洋海隆进行调查研究的方向及着力点。This paper reviews the China＇s investigate of the seafloor hydrothermal activity and polymetallic sulfide resources on the East Pacific Rise and its neighbors. Nearly 12 years,we have studied the polymetallic sulfide,Fe-Si-Mn oxyhydroxides,hydrothermal plume,metalliferous sediment and basalt,carried on the preliminary analysis to the polymetallic sulfide resource potential of East Pacific Rise near 13°N. The results show that the relationship between mineral facies of polymetallic sulfides and its elements and isotopes,and the quick settling of hydrothermal plume particles resulted in the lower REE content and higher Mn content of these Fe-Si-Mn oxyhydroxides. Further,we offer a new method for automatic calculation on the temperature anomaly of hydrothermal plume,and it is very possible that there might exist a new hydrothermal vent site in the EPR near 13°N. In addition,the chemical alteration at the rims of the plagioclase microphenocrysts and the edges of basaltic glass fragments can be divided into 5 and 4 types of alteration,respectively. The chemical characteristics of basalts from EPR near 1° ~ 2°S can be formed by mixing of N-MORB and E-MORB magmas,and the enriched compositions of basalts may be from a hotspot magma near the spreading axis of Galpagos. The resources estimates of polymetallic sulfide are made based on the volume of polymetallic sulfide mound or the shape of vent group,and the conservative resources of polymetallic sulfide in the EPR near 13°N is more than 2×107t. On this basis,we further clarify the direction and focus of future research in this area.

关 键 词：海底热液活动 多金属硫化物 资源潜力 东太平洋海隆 

分 类 号：P736.1[天文地球—海洋地质] P744[天文地球—海洋科学]