Model of Indium Ore Formation

Abstract

Indium occurs in different types of ore deposits of all ages, from the presently-forming deposits at modern, actively spreading ridges and fumarole precipitates of active volcanoes to deposits in the Archean volcanic strata of the Abitibi and Murchison greenstone belts of Canada and South Africa, respectively. Indium deposits encompass many different types of ore deposits, including volcanic- and sediment-hosted exhalative massive sulfide deposits, epithermal deposits, polymetallic base metal vein deposits, granite-related tin-base metal deposits, and skarn deposits. These deposits are commonly associated with active oceanic or continental plate margins and orogenic belts with steep geothermal gradients due to magmatic activity. Close affinities to former active subduction environments and/or collision processes are also reflected by the formation ages of indium-bearing deposits which clearly scatter around geotectonically active periods, namely the Ordovician, the Carboniferous, the Late Cretaceous, and Tertiary (cf., Figs. 5.1–5.3). Different crustal environments of indium deposition are shown schematically in Figure 6.1.