九州-帕劳海脊南段共生多金属结核与富钴结壳地球化学特征及其资源意义  

Geochemical characteristics and resource significance of polymetallic nodules and cobalt-rich crusts in the southern Kyushu-Palau ridge

作　　者：宋维宇 李超[3] 孟祥君[1,2] 黄威 赵京涛 陆凯 徐磊[1,2] 胡邦琦 虞义勇 孙建伟[1,2] 李阳 周吉祥 胡刚 原晓军[1,2] SONG Weiyu;LI Chao;MENG Xiangjun;HUANG Wei;ZHAO Jingtao;LU kai;XU Lei;HU Bangqi;YU Yiyong;SUN Jianwei;LI Yang;ZHOU Jixiang;HU Gang;YUAN Xiaojun(Qingdao Institute of Marine Geology,China Geological Survey,Qingdao 266237,China;Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266237,China;Xiamen University,Xiamen 361005,China)

机构地区：[1]中国地质调查局青岛海洋地质研究所,青岛266237 [2]青岛海洋科学与技术试点国家实验室海洋矿产资源评价与探测功能实验室,青岛266237 [3]厦门大学,厦门361005

出　　处：《海洋地质与第四纪地质》2022年第5期149-157,共9页Marine Geology & Quaternary Geology

基　　金：中国地质调查局国家专项(DD20221720,DD20191010,DD20191003);自然资源部海底科学重点实验室开放基金(KLSG2005)。

摘　　要：深海多金属结核与富钴结壳富含Mn、Co、Ni、Cu及稀土等元素,极具资源潜力,因而广受关注。选择采集自九州-帕劳海脊南段水深约3000 m的6个多金属结核和2个富钴结壳样品进行地球化学特征研究。结果显示本区样品Mn/Fe比值为0.88~1.07,Co及稀土元素含量高,与库克群岛多金属结核元素特征相似,表现出典型的水成成因特征。与其他地区水成结核、结壳相比,样品具有较高的Ca含量,可能和其所在位置海脊部位水深较浅、位于碳酸盐补偿深度(CCD)以上有关。样品表现出Y负异常、Nd含量高等水成结核的特点,但微弱的Ce正异常特征与其他地区水成多金属结核/壳的强烈Ce正异常特征不同,这表明其生长于弱氧化环境。本区结核分布在CCD以上,最小溶氧层(OMZ)以下,是一种水成成因、贫氧生长的新型多金属结核,其物质来源、成矿模式将为揭示多金属结核的形成分布规律提供一条全新的认识途径。同时研究区结核、结壳Co及稀土元素含量较高,且分布位置较浅,易于开采,具有一定的资源潜力。Deep-sea polymetallic nodules and cobalt-rich crusts are abundant in a variety of valuable metals with great resource potential.In this paper,6 polymetallic nodules and 2 cobalt-rich crusts were collected from the southern section of the Kyushu-Palau ridge at a depth of about3 000 m and their geochemical characteristics were analyzed and revealed.Results show that the Mn/Fe ratios of the samples range from 0.88 to1.07,and the contents of Co and rare earth elements are high,which is similar to the polymetallic nodules in Cook Islands,showing typical hydrodiagenetic nodules and crusts.Compared to other high potential areas of the global ocean,our samples have higher Ca content,which might be related to the shallow water depth(above the carbonate compensation depth).Negative Y anomaly and high Nd content show characteristics of hydrogenic origin,but the weak positive Ce anomaly makes it different from other hydrogenic nodules/crusts,showing strong negative Ce anomaly,indicating that the samples grew in a weak oxidation environment.Therefore,distribution above CCD,growth in weak oxidation environment,and unique elements characteristics manifested that the nodule in the study area is a new type of polymetallic nodules,and the study of its elements source and mineralization mechanisms will provide a new insight to understand the formation and distribution of polymetallic nodules.In addition,with high Co and rare earth elements content,and shallow distribution,nodules and crusts in this area are easy to exploit with promising resource potential.

关 键 词：多金属结核 富钴结壳 稀土元素 九州-帕劳海脊 

分 类 号：P736.3[天文地球—海洋地质]