Finding of cuprous gold in ferromanganese crust from the Alba Guyot of the Magellan Seamounts

Abstract

A 10 μm particle of cuprous gold was found in the phosphate-argillaceous matrix of a three-layer Fe-Mn crust dredged from the Guyot Alba of the Magellan Seamount (Pacific Ocean). The gold was studied with a scanning electron microscope at the Institute of Volcanology and Seismology, Far East Branch of the Russian Academy of Sciences. The gold is represented by cuprous gold with an admixture of platinum (up to 3.1 wt % Cu and up to 1.7 wt % Pt). The composition of impurities suggests an ophiolitic source of gold. The shape of the grain and its presence in the unaltered matrix indicates its allothigenic nature. This finding expands the list of of the Pacific Ocean guyots with allotigenic gold particles found on the surface.

Keywords

• cuprous gold
• ferromanganese crusts
• magellan seamounts
• alba guyot