Low- and high-alumina komatiites of Goiás, Central Brazil

Kuyumjian, Raul Minas; Jost, Hardy

doi:10.1016/j.jsames.2005.11.003

Cited by 15 publications

(3 citation statements)

References 47 publications

(62 reference statements)

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“…The Archean-Paleoproterozoic Terrane of Goiás extends over approximately 50,000 km 2 , and 30% of it consists of volcano-sedimentary sequences of the greenstone belt type and 70% comprises granite-gneiss rocks, thus forming a typical granite-greenstone terrane ( Fig. 2) (Almeida et al 1977, Danni et al 1981, Jost & Oliveira 1991, Kuyumjian & Jost 2006. The greenstone belts occur in five narrow belts, three of which (Crixás, Guarinos and Pilar de Goiás) are located in the northern end, and two of them (Serra de Santa Rita and Faina) are located in the southern end.…”

Section: Regional Geologymentioning

confidence: 99%

“…The greenstone belts Serra de Santa Rita and Faina are located in the southern part of the granite-greenstone terrane, and they are structured in a syncline that is NW-SE aligned, 150-km long and 6 km wide (Kuyumjian & Jost 2006, Baêta et al 1998. These belts are separated by the strike-slip Faina Fault, which strikes to N30E (Resende et al 1998), and they are located between two granite-gneiss complexes with distinct geologic evolution.…”

Section: Regional Geologymentioning

confidence: 99%

“…These belts host important gold deposits and are preserved in elongated synforms isolated by the Archean granite-gneiss complexes Hidrolina, Moquém, Caiamar, Anta, Caiçara and Uvá (Pimentel et al 2000, Jost & Fortes 2001 (Fig. 2).The greenstone belts Serra de Santa Rita and Faina are located in the southern part of the granite-greenstone terrane, and they are structured in a syncline that is NW-SE aligned, 150-km long and 6 km wide (Kuyumjian & Jost 2006, Baêta et al 1998. These belts are separated by the strike-slip Faina Fault, which strikes to N30E (Resende et al 1998), and they are located between two granite-gneiss complexes with distinct geologic evolution.…”

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Prospectivity analysis of gold and iron oxide copper-gold-(silver) mineralizations from the Faina Greenstone Belt, Brazil, using multiple data sets

et al. 2017

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ABSTRACT:The Faina Greenstone Belt is located in the southern sector of the Goiás Archean Block and has been investigated since the 18 th century because of its gold deposits. Recent studies have revealed the polymetallic potential of the belt, which is indicated by anomalous levels of Ag, Cu, Fe and Co in addition to Mn, Ba, Li, Ni, Cr and Zn. This study was developed based on a detailed analysis of two selected target sites, Cascavel and Tinteiro, and multiple data sets, such as airborne geophysics, geochemistry and geological information. These datasets were used to create a final prospectivity map using the fuzzy logic technique. The gold mineralization of Cascavel target is inserted in an orogenic system and occurs in two overlapping quartz veins systems, called Mestre-Cascavel and Cuca, embedded in quartzite with an average thickness 50 cm and guidance N45º-60ºW/25ºSW with free coarse gold in grains 2-3 mm to 3 cm. The prospectivity map created for this prospect generated four first-order favorable areas for mineralization and new medium-favorability foci. The Tinteiro area, derived from studies conducted by Orinoco do Brasil Mineração Ltda., shows polymetallic mineralization associated with an iron oxide-copper-gold ore deposit (IOCG) system posterior to Cascavel target mineralization. Its prospectivity map generated 19 new target sites with the potential for Au, Cu and Ag mineralization, suggesting new directions for future prospecting programs. KEYWORDS:Faina Greenstone Belt; aeromagnetometry; gamma spectrometry; gold mineralization; polymetallic mineralization; fuzzy logic. RESUMO: O Greenstone Belt INTRODUCTIONGlobally, mining companies seek to utilize prospective efficient methods that decrease costs during mineral exploration stages. To achieve such goals, they must use techniques that efficiently aggregate the data generated in the different stages of a given study by focusing on models that have a greater likelihood of estimating deposits (Robert et al. 2007). Magnetic surveys coupled with high-resolution gamma spectrometry data represent available technology in airborne geophysics for the detection of relevant structures for mineral exploration, and they have been shown to be efficient in the selection of follow-up target sites in tropical terranes (Silva et al. 2012, Carrino et al. 2011.The Faina Greenstone Belt is the target of this study, and, along with the Pilar de Goiás, Guarinos, Crixás and Serra de Santa Rita belts, it is part of the granite-greenstone terranes of the Archean-Paleoproterozoic terrane of Goiás, which is located in the northern sector of the Brasília Belt (Pimentel et al. 2004, Jost et al. 2005, Jost et al. 2013. This region has been investigated since the time of the Bandeirantes explorers (18 th and 19 th centuries) and shows the potential to host gold (Au) mineralizations. Several companies have mined in the area, including the well-known Metais de Goiás S.A. (METAGO), Western Mining Co., Amazônia Mineração and Troy Resources Brazil.The discovery of Sertão, a low-tonnag...

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Section: Regional Geologymentioning

confidence: 99%

Section: Regional Geologymentioning

confidence: 99%

mentioning

confidence: 99%

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Prospectivity analysis of gold and iron oxide copper-gold-(silver) mineralizations from the Faina Greenstone Belt, Brazil, using multiple data sets

et al. 2017

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Geochemical Constraints on Cumulate Textured Ti-rich Al-depleted Komatiites from Chotanagpur Gneissic Complex, Eastern India

Prasad

Bhattacharya

2016

Journal of the Geological Society of India

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For the first time occurrence of Ti rich Al depleted ultramafic cumulates having komatiitic signature in the northwestern fringe of Chotanagpur Gneissic Complex is presented. These rocks exhibit intrusive relationship with metasedimentary rocks and metaultramafites. Geochemically they are characterized by Mg# 79.1-91.60, high TiO2 (1.29-1.54 wt%), significantly low Al2O3/TiO2 and (Gd/Yb)n >1. Major oxides, trace and REE content suggest low degree of fractional crystallization and lesser degree of partial melting. These Al depleted komatiites are characterized by high concentration of incompatible elements than most suites of Barberton type komatiites. High Ti content suggests less degree of majorite garnet melting, leaving behind garnet in the restite. The rock shows higher Ti/Sc (190), Ti/V (22), Zr/Y (3), Zr/Sc (4), V/Sc (8), Zr/Sm (28) and Zr/Hf (47) ratios than primitive mantle and REE distribution pattern shows gentle slope from LREE to HREE in most samples pointing towards mantle metasomatism and crustal contamination during emplacement. The observed chemical characteristics indicate derivation of komatiite from an enriched mantle source and represent plume activity in an extensional tectonic regime of intracratonic setting.

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Mass-dependent and mass-independent sulfur isotope fractionation (δ34S and δ33S) from Brazilian Archean and Proterozoic sulfide deposits by laser ablation multi-collector ICP-MS

et al. 2012

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Low- and high-alumina komatiites of Goiás, Central Brazil

Cited by 15 publications

References 47 publications

Prospectivity analysis of gold and iron oxide copper-gold-(silver) mineralizations from the Faina Greenstone Belt, Brazil, using multiple data sets

Prospectivity analysis of gold and iron oxide copper-gold-(silver) mineralizations from the Faina Greenstone Belt, Brazil, using multiple data sets

Geochemical Constraints on Cumulate Textured Ti-rich Al-depleted Komatiites from Chotanagpur Gneissic Complex, Eastern India

Mass-dependent and mass-independent sulfur isotope fractionation (δ34S and δ33S) from Brazilian Archean and Proterozoic sulfide deposits by laser ablation multi-collector ICP-MS

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