gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

by Pedro Jacobi

A garimpeiro called Francisco Lopes Pereira found a small quartz-Py vein. Latter, in August 1993, Pedro Jacobi, while consulting for RTZ visited and sampled the occurrence. Results averaging more than 40g/t Au were encouraging and the area was selected for further work. gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

An agreement with the mineral right owner, Matapi, was written. gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

Preliminary soil gridding outlined a major gold anomaly, which encompassed the Py occurrence. Several gossan outcrops and highly (>100g/t Au) anomalous blocks of massive sulfide, mostly pyrite, were found. gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

The area was covered with geochemistry and geophysics (IP/Mag). gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

Drilling started immediately and the Ouro Roxo orebody was discovered. gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

The Ouro Roxo Project was conducted by several geologists (Carlos Sena, Ivanir Luchesi, Marcelo Pinto and Elton Pereira) and supervised by Pedro Jacobi during the following years.

After this initial stage a preliminary reserve of more than 1Mt @ 12-13g/t Au was calculated. The possibility to mine a richer but smaller orebody exists. Nevertheless the target was considered small for RTZ's standards and the area returned to Matapi.

Geology and Mineralization: gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

Ouro Roxo is situated in the southern portion of a major shear belt called Canta Galo-Ouro Roxo Shear. Milonites and protomilonites of dioritic composition of Archaen to lower Proterozoic age underlie the area. During Proterozoic (1.84Ga) granitic plugs intruded these milonites. ouro, cobre, molibdenita, pórfiros, exploração mineral, amazônia, brasil, geologia, consultor, áreas, garimpos, minerais, quartzo, tantalita, ametista, citrino, diamantes, tapajós, gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

A new, brittle deformation, period affected these sequences. Hydrothermal solutions related to these granites percolated trough late stage gash fractures and major dilation zones causing the Ouro Roxo orebody. gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

Main mineralization is represented by quartz-chlorite/sericite-sulfide–carbonate-gold veins. Pyrite is the dominant sulfide, followed by chalcopyrite (up to 1.5% Cu in intervals). Sphalerite is rare. ouro, cobre, molibdenita, pórfiros, exploração mineral, amazônia, brasil, geologia, consultor, áreas, garimpos, minerais, quartzo, tantalita, ametista, citrino, diamantes, tapajós, gold

The correlation between sulfides and gold is very good (gold is in average>50g/t in any massive sulfide) and between Cu and Au excellent. Alteration is restricted to the main fractures and selvages. A secondary enrichment of gold in laterites is remarkable. A factor of 10 x the average gold content of the saprolite was frequently observed. The possibility of additional reserves should be considered.ouro, cobre, molibdenita, pórfiros, exploração mineral, amazônia, brasil, geologia, consultor, áreas, garimpos, minerais, quartzo, tantalita, ametista, citrino, diamantes, tapajós, gold

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ouro, cobre, molibdenita, pórfiros, exploração mineral, amazônia, brasil, geologia, consultor, áreas, garimpos, minerais, quartzo, tantalita, ametista, citrin diamantes, tapajós,

gold, copper, molly, mineral exploration, brazil, amazon, geology, consultant, properties, minerals, tantalite, porphyries, consultants, quartz, amethyst, diamonds, tapajos, garimpo, garimpeiro

ouro, cobre, molibdenita, pórfiros, exploração mineral, am

azônia, brasil, geologia, consultor, áreas, garimpos, minerais, quartzo, tantalita, ametista, citrino, diamantes, tapajós, gold