Exploration for orogenic gold deposits – with emphasis on geochemical exploration in glaciated Precambrian terrain / Разведка орогенных месторождений золота – с акцентом на геохимические исследования в области докембрийского оледенения

An orogenic gold deposit is a structurally controlled gold occurrence formed during one of the major stages of an orogeny by orogenic fluids. Any rock type within a greenstone or schist belt, a metamorphosed supracrustal rock, dyke, or intrusion within or intrusion bounding such belt may host an orogenic gold deposit. There is strong structural control of mineralization at a variety of scales but the favoured host is typically the locally most reactive and/or most competent lithological unit. These deposits are not present in post- or anorogenic intrusions or unmetamorphosed supracrustal rocks. Most of the Precambrian deposits were formed during 2.70–2.60 Ga and 2.10–1.70 Ga. These epochs appear to be related to rapid crustal growth and accretionary stages of supercontinents. Mineralisation typically takes place during the last major stage of an orogeny. The late timing of this deposit type to provide important geological aids in exploration as the geometry of the geological units has not significantly changed after the mineralisation. Hence computer aided methods like geomechanical stress modelling can be utilised to model structurally favourable sites <...>