The Idaho Cobalt Belt (ICB) is a unique example of sea-floor hydrothermal brines that vented along an ancient rift within a deep-water setting, providing for an interesting and distinctive geochemistry. The ICB is a northwest-trending zone of Co-Cu-Au occurrences, at least 64 km long and up to 10 km wide, centered on the Company’s Idaho Cobalt Operations (“ICO”). It is an exceptional metallogenic province in which cobalt occurs in sufficiently high concentrations to make it the primary metal in the deposits.
The deposits are mostly strata-bound and appear to have formed during a mafic volcanogenic-exhalative mineralizing event on a paleo-sea-floor ca1600 m.y. ago. More recent regional metamorphic events have remobilized Cu and, to a lesser extent, Co in varying degrees throughout the belt. The deposits are unusually rich in Co, Cu, Fe, As, Au, B, Bi and light rare earths, but low in Ni (relative to Co), Ag, Pb, and Zn. The synsedimentary controls, mineralogy and geochemistry are unusual among ore deposits, though similar features in some other deposits are known. Sediment-hosted deposits are major ore producers in the world, but unlike the ICB, most tend to be Pb and Zn rich. Some sediment-hosted deposits that contain Cu also contain Co – notably, the deposits of the Katanga province of the Democratic Republic of the Congo (DRC) and the adjoining Zambian Copperbelt deposits. Significant differences exist between deposits in these west African deposits and the ICB, whereas many intriguing similarities are found between ICB deposits and Sullivan, Canada, and Mount Isa and Broken Hill, Australia.
The ICB is currently known to host several Co-Cu deposits within several sequences of metamorphosed, mafic volcaniclastic rocks. The ICO encircles the inactive Blackbird mine and encompasses the Ram, Sunshine and East Sunshine deposits and more than a dozen underexplored prospects and exploration targets.