海洋学研究 ›› 2020, Vol. 38 ›› Issue (2): 16-25.DOI: 10.3969/j.issn.1001-909X.2020.02.003

• 研究论文 • 上一篇    下一篇

南海东北部陆坡结核成因及对冷泉活动的指示

陆怡1,2, 初凤友*1,2, 董彦辉1,2, 朱志敏1,2, 朱继浩1,2, 鲁江姑1,2   

  1. 1.自然资源部 第二海洋研究所,浙江 杭州 310012;
    2.自然资源部 海底科学重点实验室,浙江 杭州 310012
  • 收稿日期:2020-01-06 出版日期:2020-06-15 发布日期:2020-11-13
  • 通讯作者: *初凤友(1964-),男,研究员,主要从事海底资源与成矿系统研究。E-mail:chu@sio.org.cn
  • 作者简介:陆怡(1993-),女,山东省青岛市人,主要从事多金属结核成矿研究。E-mail:luyijane@126.com
  • 基金资助:
    大洋“十三五”资源环境课题资助(N1-01-06,N2-1-03,N1-01-01);自然资源部第二海洋研究所基本科研业务费项目资助(JT1304)

Formation of nodules on continental slopes in thenortheast of the South China Sea and itsimplications for cold seep

LU Yi1,2, CHU Fengyou*1,2, DONG Yanhui1,2, ZHU Zhimin1,2, ZHU Jihao1,2, LU Jianggu1,2   

  1. 1. Second Institute of Oceanography, MNR, Hangzhou 310012, China;
    2. Key Laboratory of Submarine Geosciences, MNR, Hangzhou 310012, China
  • Received:2020-01-06 Online:2020-06-15 Published:2020-11-13

摘要: 本文对2018年利用“海龙Ⅲ”ROV在南海东北部陆坡采集到的多金属结核样品进行了矿物学和地球化学分析。结果表明研究区结核以棒状为主,具有2层结构。结核外层的矿物学和元素组成特征与水成型多金属结核较为相似。结核内层多发育孔洞,以针铁矿为主,有黄铁矿残余,Fe、As元素含量高,Mn、REE等元素含量低。NH-2结核样品内部的碳酸盐组分的全岩δ13C为-30.91‰。所研究结核样品的早期形成过程与冷泉活动密切相关,结核生长后期冷泉活动停止或是减弱,在等深流作用下结核黄铁矿被氧化成针铁矿,之后锰铁氧化物继续在结核外部生长。

关键词: 结核, 冷泉, 南海, 东沙, 大陆坡

Abstract: The polymetallic nodule samples were analyzed for their mineralogical and geochemical features, which were acquired on the northeastern slope of the South China Sea using the ROV named as Sea Dragon III. The results showed that the nodules in the study area were predominantly by rod-shaped with a two-layer structure. The outer layer of the polymetallic nodules was mineralogically and geochemically similar to hydrogenic nodules. While the inner layer was porously and composed of goethite with residual minor pyrite. Geochemically, the inner layer was characterized by high concentration of Fe and As but extremely low concentration of Mn, REE and other elements. The inner layer carbon isotopes ( δ13C ) of sample NH-2 was -30.91‰. The study presented that the early forming process of the nodules was related to the activities of cold seep, but the pyrite was oxidized following the extinction of cold seep. Under the influences of contour current in the area, the ferromanganese oxides continued to grow in the outer layer of the nodules.

Key words: cold seep, South China Sea, Dongsha, continental slopes

中图分类号: