Major Brazilian gold deposits – 1982 to 1999

Authors: Charles H Thorman Ed DeWitt Marcos A Maron Eduardo A Ladeira

Publish Date: 2001/05/19

Volume: 36, Issue: 3-4, Pages: 218-227

PDF Link

Abstract

Brazil has been a major but intermittent producer of gold since its discovery in 1500 Brazil led the world in gold production during the 18th and early 19th centuries From the late 19th century to the late 20th century total mining company and garimpeiro production was small and relatively constant at about 5 to 8 t/year The discovery of alluvial deposits in the Amazon by garimpeiros in the 1970s and the opening of eight mines by mining companies from 1983 to 1990 fueled a major boom in Brazils gold production exceeding 100 t/year in 1988 and 1989 However garimpeiro alluvial production decreased rapidly in the 1990s to about 10 t/year by 1999 Company production increased about tenfold from about 4 t/year in 1982 to 40 t in 1992 Production from 1992 to the present remained relatively stable even though several mines were closed or were in the process of closing and no new major mines were put into production during that periodBased on their production history from 1982–1999 17 gold mines are ranked as major 20 t and minor 3–8 t mines From 1982–1999 deposits hosted in Archean rocks produced 66 of the gold in Brazil whereas deposits in Paleoproterozoic and Neoproterozoic rocks accounted for 19 and 15 respectively Deposits in metamorphosed sedimentary rocks especially carbonaterich rocks and carbonate ironformation yielded the great bulk of the gold Deposits in igneous rocks were of much less importance The Archean and Paleoproterozoic terranes of Brazil largely lack basemetalrich volcanogenic massive sulfide deposits porphyry deposits and polymetallic veins and sedimentary exhalative deposits An exception to this is in the Carajás Mineral Province

Keywords: