Sources of Noble Metals in Iron-Manganese Formations of the Northwest Pacific Marginal Seas
We analyzed the distribution of noble metals (Au, Ag, Pt, Os, Ir and Ru) in iron-manganese formations (IMF) and found the presence of micro- and nano-scale grains of Ag, Au, Pd, and Pt often mixed with other elements. We conclude on the basis of their irregular distribution that the three sources of these metals in ore formations are: seawater, hydrothermal water plums, and post-magmatic emissions of fluids and gases. The presence of the grains of platinum group elements and gold in the IMF found only in some submarine elevations may be caused by the peculiarities of the formation of volcanic rocks on the ancient continental basement.