海底水一沉积物界面系统中成矿元素的组合特征与多金属结核形成的关系

利用“海洋四号”调查船HY4—871,881航次在东太平洋海盆取得的底层水、沉积物、间隙水及多金属结核样品,研究探讨了海底水—沉积物界面系统不同物质相中结核主要成矿元素间的关系,并以此为基础讨论了结核成矿元素的来源及其成矿机制。研究表明,Mn、Fc在底层水和沉积物中表现出一定的正相关关系。而在间隙水和结核中则发生了完全相反的变化。间隙水中Mn、Fc密切共生,而结核中Mn、Fc则高度离散,这表明在沉积物早期成岩阶段,Mr~Fc在间隙水中有着相同的溶出富集机制,而在结核形成过程中则有着完全不同的沉淀聚集机制。此外,Co、Ni、Cu与Mn、Fc之间组合关系的变化则反映了不同海底作用的影响。底层水与结核及间隙水与结核相应元素之间关系的变化表明结核主要成矿元素的来源不同,Mn、Ni、Cu主要来源于间隙水,Fc、Co则主要来源于底层水。

RELATION BETWEEN ASSOCIATION OF Mn, Fe, Ni,Cu AND Co IN WATER-SEDIMENT SYSTEM AT THE OCEAN FLOOR AND FORMATION OF POLYMETALLIC NODULES

On the basis of chemical analysis,the inter-clement relationship of Mn, Fc,Ni,Cu,and Co in bottom water, sediments, interstitial water and polymctallic nodules collected from the Eastern Pacific Basin during the cruises of R/V Haiyang 4 - 871,881 was disscusscd. Mn is positively related to Fc in bottom water, sediments and interstitial water. But Mn is negatively related to Fc in polymctallic nodules.It is suggested that Mn and Fc have the same dissolution enrichment mechanism in interstitial water, but have different precipitation enrichment mechanism in polymctallic nodules. The variations of assiciations of Mn Fc,Ni,Cu and Co is the result of different gcochcmical processes. Mn,Ni,and Cu in nodules arc mainly deposited from interstitial water, and Fc and Co arc mainly deposited from bottom water.