Enigma of Alluvial Gold Mining in Pre-Contact Peru—The Present Is Key to the Past

Abstract

Peru has produced metals for thousands of years and is the leading gold producer in Latin America today; however, the indigenous mining technology used to produce industrial amounts of gold in pre-contact Peru has thus far been undescribed. Industrial amounts of gold are produced in only two ways: 1) gravity separation/mercury (amalgamation), and 2) cyanide. Therefore, an understanding of present-day gold mining methods is key to understanding gold mining in the past. For example, in 2018, Peru’s large-scale open-pit gold mines produced 123,767 kg of gold using cyanide and 18,875 kg of gold were produced from small-scale alluvial gold mines that used gravity separation and mercury. Since cyanide was not used until the 1880s, mercury amalgamation must be critiqued as the mining technology that produced prodigious amounts of gold from alluvial sources in pre-contact Peru.