Focus of the largest gold rush in Brazil in the latter part of the 20th century with unofficial production of 30 million ounces of gold.
High potential for the discovery of primary mineralization in this large, under-explored region of northern Brazil.
The Tapajós Mineral Province (TMP) was the focus of the largest gold rush in Brazil in the latter part of the 20th century with unofficial production of 30 million ounces of gold. Most of this gold was recovered from hydraulic mining by artisanal miners (garimpeiros) of alluvial deposits with lesser contributions from eluvial, colluvial and primary deposits. To date, there has been no significant commercial mine in the TMP, however the widespread alluvial gold, suggests very good potential for the discovery of primary mineralization in this large, under-explored region of northern Brazil.
The TMP covers an area of approximately 125,000 km² and encompasses the southwestern part of Pará state, the eastern part of Amazonas state and the northern part of Mato Grosso state. The area is drained by the Tapajós River and its tributaries that flow northeastward into the Amazon River.
Access to the area is largely by small aircraft from Itaituba to the hundreds of air strips in the region. The airstrips were mostly built by the garimpeiros to support their mining operations, but are now largely abandoned or only support a few workers. Itaituba, a city of approximately 120,000 people and located on the Tapajós River, was the hub of the gold rush and now supports most of the exploration activities in the region. The Transamazonia, Santarém–Cuiabá (BR163) and Transgarimpeiro Highway's provide access to some areas of the TMP.
The TMP is situated within the western portion of the Archean to Proterozoic Amazon craton. The area is underlain by a number of different granitic suites and associated volcanic rocks that can be un-deformed to strongly deformed and metamorphosed. Primary gold mineralization commonly occurs in veins and stockworks hosted in the granitic or felsic volcanic rocks in a porphyry to epithermal setting. Tocantinzinho is the largest deposit discovered to date, however other significant deposits include Cuiú-Cuiú, São Jorge, V3 and Ouro Roxo.