Annotated record of the detailed examination of Mn deposits from the H.M.S. Penguin expedition to the Coral Sea

The analyses of the samples from the Balfour Shoal show that these deposits contain a very large quantity of carbonate of lime, ranging from 88.7 per cent, on the summit to 71.9 per cent, in the deeper water at the base of the cone. The decrease in the quantity of carbonate of lime with increase of depth is not quite regular; still, a general fall in the percentage of lime is clearly indicated from shallower to deeper water. As might be expected in such a circumscribed area, there is a great uniformity both in the chemical composition and relative abundance of the organic and inorganic constituents of the deposits. In all cases the carbonate of lime is almost wholly made up of the dead shells which have fallen from the surface waters - belonging to Plankton organisms such as Pteropods, Heteropods, pelagic Foraminifera and coccoliths. The calcareous shells were in very many cases discoloured brown or black by depositions of the peroxide of manganese. On the north-east steep side of the Balfour Shoal there were indications that depositions of manganese peroxide were more abundant than elsewhere. In 1645 fathoms, there was an angular fragment of a mottled yellowish jasper coated with manganese peroxide, and in 1570 fathoms there were three characteristic spherical black manganese nodules from one-half to three-fourths of an inch in diameter, quite similar to those procured by the Challenger in many areas of the Pacific and Atlantic. In one of these nodules the nucleus was a sub-angular fragment of a light-coloured augite-granophyre.

对巴尔弗浅滩（Balfour Shoal）的样本分析结果显示，该区域沉积物含有极大量的碳酸钙（carbonate of lime），其含量范围从浅滩顶部的88.7%到锥体基底深水区域的71.9%不等。碳酸钙含量随深度增加的变化并非完全规律，但整体上仍清晰呈现出从浅水区到深水区石灰质百分比逐渐下降的趋势。正如这类局限海域的典型特征，沉积物的化学成分以及有机、无机组分的相对丰度均表现出高度的一致性。所有样本中的碳酸钙几乎全部由表层水域沉降的死亡壳体构成，这些壳体属于翼足类（Pteropods）、异足类（Heteropods）、浮游有孔虫（pelagic Foraminifera）以及颗石藻（coccoliths）等浮游生物。钙质壳体在多数情况下因二氧化锰（peroxide of manganese）沉积而呈现棕褐色或黑色。在巴尔弗浅滩的东北陡坡区域，二氧化锰沉积的丰度高于其他区域。在1645英寻水深处，采集到一块被二氧化锰包裹的斑驳黄褐色碧玉棱角状碎屑；在1570英寻水深处，发现了三个典型的球形黑色锰结核，直径介于0.5至0.75英寸之间，与挑战者号（Challenger）在太平洋和大西洋诸多区域采集到的锰结核极为相似。其中一枚锰结核的核心为浅色透辉石花岗斑岩（augite-granophyre）的次棱角状碎屑。