东太平洋CCFZ区多金属结核元素富集机制:来自结核剖面原位微区分析

多金属结核微层原位微区分析能够更好地揭示结核生长过程中元素的赋存和迁移过程,为认识多金属结核元素富集机制和成因提供新的证据.通过使用电子探针(EPMA)和激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)等手段对采集自东太平洋克拉里昂?克利珀顿断裂区(CCFZ区)的多金属结核进行了分析研究.研究结果表明,结核矿物主要为...

Elements Enrichment Mechanism of Polymetallic Nodules in CCFZ area of Eastern Pacific Ocean: In-Situ Microanalysis of Nodule Profile

In-situ microanalysis of polymetallic nodule can better reveal the occurrence and migration of elements in the growth process of polymetallic nodules than bulk nodule analysis, and provide new evidence for understanding the enrichment mechanism and genesis of polymetallic nodules. In this study, electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) were used to analyze the polymetallic nodule collected from the Clarion-Clipperton Fault Zone (CCFZ) of the East Pacific Ocean. The results show that the main minerals of the nodule are vernadite, 10 ? manganite and FeOOH. From the inside to the outside, the ferromanganese nodule can be divided into four distinct layer groups: L1, L2, L3 and L4, the average contents of Mn and Fe are 32.2 and 13.3%, 39.1 and 5.2%, 37.0 and 3.4%, 33.1 and 7.8%, respectively. The Mn/Fe ratio increases as a whole, and corresponding to 2.8, 16.6, 19.7 and 10.6, respectively. The variation of Co+Ni+Cu content shows similar trend, with the average content of 1.9%, 3.3%, 3.8% and 3.0%, respectively.The relationship of element content shows that Co mainly occurs in hydrogeneticvernadite, Ni and Cu both occur in hydrogenetic and diagenetic Mn phase minerals, while the enrichment ability of diagenetic 10 ? manganite is stronger than hydrogeneticvernadite. Based on the element composition and microstructure, the layers can be divided into hydrogenetic layer, mixed layer, diagenetic layer and mixed layer, respectively, and the nodules experienced hydrogenetic growth and diagenetic growth successively.