【作者】 景春雷；

【导师】 刘保华； 郑彦鹏；

【作者基本信息】 国家海洋局第一海洋研究所 ， 海洋地质， 2012， 硕士

【摘要】 海底热液活动是20世纪海洋科学领域最重要的发现之一。现代海底热液活动及资源效应的研究已成为当前地球科学研究的热点，海底热液多金属硫化物也成为受到国际关注的海底矿藏。2010年5月，经国际海底管理局理事会批准，中国在西南印度洋获得了1万平方公里具有专属勘探权并在未来享有优先开采权的多金属硫化物资源矿区。要想全面认识海底多金属硫化物矿床，并对这些潜在资源进行开发，首先需要了解海底热液活动的分布规律、海底多金属硫化物矿形成的区域地质环境、以及区域地质背景条件对海底热液多金属硫化物矿体规模、成矿机制等的控制作用等相关科学问题。本论文通过广泛收集国内、外已有的调查研究成果，参考大量的文献资料，并对所获得的资料开展筛选、整理、图件编绘等工作，在对水深、重力、磁力、地震等数据资料的综合研究基础上，分析了全球海底多金属硫化物矿床空间分布与板块构造位置之间的相关性，讨论了典型多金属硫化物矿区的区域地质概况、基底岩石与沉积盖层、地球物理场、岩石圈深部结构等特征，探讨了制约海底多金属硫化物矿体形成与分布的主要控制因素，指出深部岩浆活动和断裂构造是控制海底热液系统和多金属硫化物成矿最关键的因素。研究表明，海底热液活动主要分布于离散型板块边界和汇聚型板块边界，其产出的板块构造位置主要可以划分为大洋中脊型（A型）构造环境、洋-弧型板块俯冲边缘形成的弧后盆地型（B型）构造环境、洋-陆型板块俯冲边缘形成的大陆边缘型（C型）构造环境以及板内热点活动型（D型）构造环境这四类。海底热液多金属硫化物的形成主要受到深部岩浆活动、断裂构造、沉积物盖层、板块扩张速率、水深、围岩类型等因素的控制，其中深部岩浆活动为多金属硫化物成矿提供了热源和矿物质元素，断裂构造为热液活动提供了重要的导矿通道和容矿裂隙。不同扩张速率的构造环境中深部岩浆活动、海底断裂构造特征及形成的多金属硫化物矿体均存在差异。分析认为深部岩浆活动和断裂构造是控制海底热液系统和多金属硫化物成矿最关键的因素。快、慢扩张构造环境深部岩浆活动和断裂构造的差异导致海底形成的多金属硫化物矿体规模不同。快速扩张构造环境的岩浆供给量大，但是由于岩浆侵入频繁，且断裂构造规模小，造成海底热液活动分散喷溢，形成的热液喷口小且活动时间短，多金属硫化物矿体规模小；在慢速扩张构造环境，虽然岩浆供给量小，但是岩浆活动稳定，且断裂构造规模大，有利于海底热液活动的集中喷溢，形成的热液喷口大且活动时间长，多金属硫化物矿体规模大。更多还原

【Abstract】 Submarine hydrothermal activity is one of the most important discoveries inthe field of marine science in the20th century, the study of modern submarinehydrothermal activity and the effect of the resources and the environment has become hotspot of earth science research nowadays. Submarine hydrothermal polymetallic sulfidesalso become the seabed deposits that receive the international concern. May2010,approved by the council of International Seabed Authority, China has obtained10thousand square kilometres seabed mining areas of exclusive exploration and prioritymining rights in the Southwest Indian Ocean. In order to understand submarinepolymetallic sulfide deposits comprehensively, and exploit these potential resources, wemust know firstly the distribution of hydrothermal activity, the regional geologicalenvironment, and its effect of size, metallogenic mechanism and other aspects ofhydrothermal polymetallic sulfides.On the basis of the latest data of global hydrothermal vent sites (588sites),extensive existing survey research results at home and abroad, as well as a large numberof documents are collected, all the collected data are picked up, rearranged and somefigures are drawn. Based on a comprehensively study of the bathymetry, gravity,magnetic, seismic and other data, the correlation between the distribution of globalsubmarine polymetallic sulfide deposits and plate tectonic positions are analysed, thecharacters of typical hydrothermal sulfide mining areas, such as geophysical field,basement rocks, sediment caps, lithosphere structure and so on, are discussed, the maincontrolling factors that constraint the formation and distribution of the submarinepolymetallic sulfides are extracted.The results show that submarine hydrothermal polymetallic sulfide vent sites mainly locate at divergent and convergent plate boundary. The plate tectonic positions can beclassified as four tectonic setting: mid-ocean ridge tectonic setting, back-arc basintectonic setting in the subducting plate edge of ocean-arc, continental margin tectonicsetting in the subducting plate edge of ocean-continent, intraplate hot spots tectonicsetting. The formation of submarine hydrothermal polymetallic sulfides is primarilycontrolled by deep magmatic activity, faults structure, sediment cap, spreading rate,water depth, the types of wall rock and other factors. Deep magmatic activity provideheat resource and mineral elements for the mineralization of the polymetallic sulfides,faults structure provide important guiding channels and fissures for hydrothermalactivity.Deep magmatic activity, submarine fault structure and the thickness of sediment inthe tectonic settings with different spreading rates are different. Deep magmatic activityand fault structure are the two most crucial controlling factors of submarine hydrothermalsystems and the mineralization of polymetallic sulfide. Different fault structure and deepmagmatic activity in fast-and slow-spreading tectonic settings contribute to different sizeof polymetallic sulfide deposits. Fast spreading tectonic settings with high magmaticbudgets, have continual diking events and small-scale fault structure. That results indispersive ejection of hydrothermal activity, small and short-lived hydrothermal vent, andsmall size of polymetallic sulfide deposits. Slow spreading tectonic settings with lowmagmatic budgets, have stable magmatic activity and large-scale fault structure. Thatcontributes to concentrated ejection of hydrothermal activity, large and longevity ofhydrothermal vents, and massive polymetallic sulfide deposits.更多还原