【摘要】 柱状构造为富钴结壳中多种微观构造类型之一。为探讨富钴结壳柱状构造的形成机制,利用高分辨率电子探针技术分析了位于中太平洋某海山的富钴结壳中柱状构造的微观形态和微区元素化学特征,结果表明,柱状构造是由围绕核心的微层呈弓形外延辐射生长逐渐分枝而成。壳层由亮色、暗色微层交替叠置而成,其中亮色微层富锰、钴、镍和氧,而暗色微层富铁和硅;同一微层各部分的生长速率不同,介于0.27~0.92 mm/Ma。柱状构造壳层亮色、暗色微层交替变化以及相应成分的不同是微观氧化还原环境变化的结果,而柱状构造的分枝和同一微层生长速率的差异则与富钴结壳生长界面有界面双电层有关。更多还原

【Abstract】 Columnar structure is one of the microstructures in cobalt-rich crusts.In order to elucidate its forming mechanism,microscopical features and microprobe element chemistries have been analyzed with a high-resolution backscattered electron probe microscope analyzer on the profile of a cobalt-rich crust from the Mid-Pacific Mountains.The results show that the columnar structure consists of the light microlayers(rich in manganese,cobalt,nickel and oxygen) and gray microlayers(rich in iron and silicon),in which they occur alternately,and the growth rates of the same microlayer are different and range from 0.27 to 0.92 mm/Ma.The reasons for the diferent colours of microlayers and the component alternation could be the change of redox environments resulting in the different phases of mineral forming.The electrical double layer of growth interface of cobalt-rich crusts could explain the bifurcation of microlayers of columnar structure and the variations of growth ratios in the same microlayer.更多还原