深海富钴结核微区X射线荧光光谱分析和数据挖掘

西太平洋富钴结核是近年来新发现的海底固体矿产资源，富含Mn，Fe，Co，Ni和Cu等多种关键金属元素。富钴结核是一种非均质的地球化学和矿物学集合体，粒径约6 cm的结核在生长过程中记录了数千万年的海洋沉积历史，亟需高分辨率的分析技术揭示古海洋环境信息。采用微区X射线荧光光谱仪（μ-XRF），对C3BC1704富钴结核开展多元素面扫描，获得了原位高分辨率多元素的信号强度数据，评价了μ-XRF技术在富钴结核中的应用质量。元素信号谱峰特征和数据频谱分布结果显示，富钴结核中Mn，Fe，Ti，Co，Ca和Ni等元素信号强度敏感，数据呈现相对较好的正态分布特征，可用于定量或半定量分析；Si，Cu和Al等元素信号较弱，数据呈现左偏的正态分布特征，建议相关数据仅作参考。μ-XRF获得的数据量庞大且彼此独立，本研究将不同元素连接成彼此关联的多维矩阵，实现了数据的位置信息和特征元素之间的数学运算和筛选，了解了金属元素的分布和变化特征，揭示了富钴结核生长过程的环境变化。结果显示，Mn和Fe等元素在生长层中波动剧烈，金属元素在富钴结核中的分布极不均匀，显示出多成因类型的交替微层和7个大的生长周期旋回。C3BC1704富钴结核主体暴露在海水中，金属元素主要来自海水，化学组成指示为典型的水成成因。进一步定量分析结果显示，Mn，Cu和Ni等元素含量从内部向外围呈现同步降低的趋势，Fe，Ti和Co等元素含量则呈现同步升高的趋势，这些特征指示早期偏向于成岩富集环境，晚期则以水成富集为主。富钴结核金属元素的分布和变化特征，清晰呈现了富钴结核的生长结构，揭示了富钴结核生长过程的环境变化，有利于富钴结核的成矿模型的构建。

μ-XRF Analysis and Data Mining of Deep-Sea Co-Rich Ferromanganese Nodules in Western Pacific

Co-rich ferromanganese nodules in the Western Pacific Ocean are rich in Mn, Fe, Co, Ni, Cu and other metal elements, which are newly discovered seabed solid mineral resources in recent years. They are heterogeneous geochemical and mineralogical aggregates. Co-rich ferromanganese nodules with a particle size of 6 cm record tens of millions of years of marine sedimentary history during their growth. Therefore, high-resolution analysis technology is urgently needed to reveal the paleo marine environmental information. In this study, we used a microscopic X-ray fluorescence spectrometer (μ-XRF) to scan the surface of C3BC1704 Co-rich ferromanganese nodule, and obtained in situ high-resolution multi-element signal intensity data, and evaluated the application quality of μ-XRF technology in Co-rich ferromanganese nodules for the first time. The results show that Mn, Fe, Ti, Co, Ca, Ni elements have sensitive signal intensity changes, and the data show relatively good normal distribution characteristics, which can be used for quantitative or semi quantitative analysis. The signals of Si, Cu, Al and other elements are weak, and their data show a left skewed normal distribution. It is suggested that the relevant data should be used for reference only. The amount of data obtained is huge and independent of each other. In this study, different elements are connected into the multi-dimensional matrix to realize the mathematical operation and screening between the location information and feature elements of the data. The distribution and variation characteristics of metal elements are understood, and the environmental changes in the growth process of cobalt rich nodules are revealed. The results show that Mn, Fe and other elements fluctuate violently in the growth layer, and the distribution of metal elements in the Co-rich ferromanganese nodules is extremely uneven, showing multiple genetic types of alternating micro layers and seven large growth cycles. The main body of the C3BC1704 Co-rich ferromanganese nodule is exposed to seawater, and its metal elements mainly come from seawater, which belongs to the typical hydrogenic types. Further quantitative analysis showed that the contents of Mn, Cu and Ni decreased synchronously from the inside to the outside, while the contents of Fe, Ti and co increased synchronously. It is indicated that the Co-rich ferromanganese nodules relatively tend to be enriched in diagenesis in the early stage and hydrogenises mainly in the late stage. The distribution and variation characteristics of metal elements clearly show the growth structure, reveal the environmental changes, and promote the construction of the metallogenic model of Co-rich ferromanganese nodules.