Gold in Paleoproterozoic (2.1 to 1.77 Ga) Continental Magmatic Arcs at the Tapajós and Juruena Mineral Provinces (Amazonian Craton, Brazil): A New Frontier for the Exploration of Epithermal–Porphyry and Related Deposits

This review paper aims to integrate geological, tectonic and metallogenetic data, including new propose a regional model for the gold (and base metal) mineralization in south Amazonian Craton support mineral exploration concerning magmatic–hydrothermal deposits. The Proterozoic evolution of comprises accretion terrains Archean Carajás Mineral Province. In Tapajós Juruena provinces, located at part craton, long-lived ocean–continent subduction event produced ca. 2.0 1.77 Ga continental magmatic arcs. Extensive lava flows, volcaniclastic, sedimentary, plutonic rocks were originated during least four major orogenic events (ca. 2.1, 1.9, 1.88, 1.80 Ga) two post- anorogenic 1.87 Ga). Gold occurs in: (i) alluvial/colluvial occurrences, (ii) carbonate–sulfide-rich quartz veins shear zones, (iii) stockworks, veins, dissemination granites, (iv) contact basic dikes, (v) well-preserved high-, intermediate- low-sulfidation epithermal mineralization, (vi) porphyry-like intrusion-related systems associated with late- post-orogenic epizonal granites. estimated historical production, mainly secondary deposits, is over 27 Moz 6 provinces. A total resource 5 Au currently defined several small large primary Andesite rhyolite, clastic sedimentary (1.96–1.88 host (high-, intermediate-, low-sulfidation) Au–(Ag–Pb–Zn) whereas Au–Cu Cu–Mo–Au hosted sub-volcanic tonalitic granitic plutons. Advanced argillic alteration (alunite, pyrophyllite, enargite) high-sulfidation ring volcanoes around nested volcanic calderas. zone grades outward propylitic or chlorite alteration, often covered by silica caps vuggy silica. Lava flows volcaniclastic within faults edifices rhyolitic domes low- intermediate-sulfidation mineralization. Low-sulfidation zones typically have adularia illite sericite. Chalcopyrite, sphalerite, galena, pyrite, digenite, manganiferous calcite are related Late- evolved oxidized I-type granitoids alkalic-type Porphyry-style hydrothermal analogous those modern systems, inner sodic potassic (potassic feldspar ± biotite biotite) alterations grading propylitic, muscovite-sericite, chlorite–sericite, alterations. Potassic locus Cu–Mo gold-rich occur muscovite/sericite–quartz–pyrite alteration. Paleoproterozoic these provinces defines frontier world-class deposits worldwide arc-related terrains.