Three-Dimensional Structural Analysis of Ferromanganese Nodules from the Western North Pacific Ocean Using X-ray Computed Tomography
Three-Dimensional Structural Analysis of Ferromanganese Nodules from the Western North Pacific Ocean Using X-ray Computed Tomography
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DOI：
10.3390/min11101100
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发表时间：
2021-10-01
期刊：
影响因子：
2.5
通讯作者：
Kato, Yasuhiro
中科院分区：
文献类型：
--
作者：
Nakamura, Kentaro;Terauchi, Daiki;Kato, Yasuhiro
使用 X 射线计算机断层扫描 (X 射线 CT) 评估了从南鸟岛周围的太平洋潜水收集的 934 个铁锰结核样本的三维层状生长结构，以阐明其生长历史。在三个正交方向上测量的层状结构的厚度表明，无论形状和大小如何，铁锰结核在所有方向上均等生长。根据CT值的差异，将层状构造细分为I、II、III、IV层，与岩石学特征相对应。然后根据是否具有 I、I 和 II、I-III 或 I-IV 亚层，将结节分别分类为 I、II、III 和 IV 型。层的总厚度和子层的数量之间的相关性表明两者都代表了结节的相对年龄。大多数采样点都发现了所有这些类型的结核，每个潜水点的总层厚度直方图显示了几个峰值。这些发现表明结节生长的开始是间歇性的，而不是同时发生的。在整个研究区域的许多地点发现了三个不同的厚度峰值，这表明至少三个覆盖数百公里的结核起始事件引发了铁锰结核的生长。
The three-dimensional layered growth structure of 934 ferromanganese nodule samples collected from dives in the Pacific Ocean around Minamitorishima Island was assessed using X-ray computed tomography (X-ray CT) to elucidate their growth history. The thickness of the layered structure measured in three orthogonal directions showed that the ferromanganese nodules grew equally in all directions regardless of shape and size. Based on differences in CT numbers, a layered structure was subdivided into sublayers I, II, III, and IV, which corresponded to petrological features. The nodules were then classified as Types I, II, III, and IV according to whether they had sublayers I, I and II, I-III, or I-IV, respectively. Correlations between the total thickness of the layers and the number of sublayers indicated that both represented the relative age of the nodules. Nodules with all these types were recovered from most of the sampling sites, and histograms of the total layer thickness at each dive site showed several peaks. These findings indicated that the initiation of nodule growth was intermittent, rather than simultaneous. Three distinct thickness peaks were found at many sites throughout the study area, suggesting that at least three nodule initiation events covering hundreds of kilometers initiated the growth of ferromanganese nodules.