Geodynamic processes that control the global distribution of giant gold deposits / Геодинамические процессы, управляющие глобальным распределением гигантских месторождений золота

This paper address the question of why giant gold deposits are so unevenly spread over the continents, what processes control their distribution, and how more might be found? Using the source-migration-trap paradigm, it is proposed that the regional distribution of gold deposits is controlled by fluid access to gold sources on a regional scale, and by large-scale migration mechanisms. Local distribution is controlled by migration and trap processes, not discussed in this paper. Our current levels of understanding of gold suggest a strong geodynamic control in the generation of enriched source rocks and the fluids that may carry gold, particularly the influence of subduction and accretion during orogeny. A new six-fold geodynamic classification system that emphasizes subduction and accretion processes has been used here qualitatively to assess the potential for gold-bearing source areas. The resulting classification is compared to the distribution of 181 known giant gold deposits (those with more than 100 t contained gold). The results confirm the proposition that the distribution of giant gold deposits is ultimately a function of the amount of oceanic crust consumed during the orogenic episode that built that part of the crust. Of the six geodynamic classes described, large ocean closure orogens were found to contain the most gold, with nearly half of the world’s gold held in known giant deposits. Implications for understanding ore genesis, exploration for other giant deposits, and for other empirical explanations of the distribution of gold are discussed further. <...>