On December 20, 2024, G Mining Ventures Corp. (“GMIN”) acquired claims in the Gurupi Gold Belt from wholly owned subsidiaries of BHP Group Limited (“BHP”). The acquisition gives GMIN a 100% interest in the tenements, including the CentroGold Project, renamed “Gurupi Project”.
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Summary:
The Gurupi Project deposits are considered typical of mesothermal or orogenic-style gold deposits.
The Gurupi Project encompasses three (3) primary mineralized zones, Blanket and Contact deposits part of Cipoeiro and the Chega Tudo deposits, located 8 km apart within the Lower Proterozoic Gurupi Greenstone Belt along the Tentugal Shear Zone.
Blanket and Contact
Mineralization at the Blanket and Contact deposits is hosted entirely within the host tonalite. Mineralization has not been identified yet within the adjacent arenite sediments of the Chega Tudo formation. The mineralized zones within the host tonalite typically parallel the dip and strike of the contact with the arenite sediments of the Chega Tudo formation. The most important controls for gold deposition appear to be the brittle fracturing, shearing, and folding of the host tonalite.
Mineralization at the Blanket deposit has been deposited in the same structural setting as the Contact deposit. Mineralization is in close proximity to the arenite contact and ranges from a few metres up to 50 m in width.
The Blanket deposit has a strike length of about 800 m, outcrops at the surface to the west, and is open down-dip, at depths below 150 m to the east. It has a semi-convex shape with a 20° to 40° azimuth and 10° to 50 deg south-easterly dip that flattens eastward, away from the tonalite-arenite fault contact. Mineralization follows diffuse ductile shears that crosscut the tonalite and is associated with quartz-sericite-pyrite alteration within moderately to strongly foliated tonalite. It is proposed the deposit is bounded on the south by the CFZ and on the north by the North Fault Zone ("NFZ"). However, the accurate demarcation of these fault zones has yet to occur as limited drilling has occurred in the vicinity of the proposed fault zones.
At the Contact deposit, mineralization is concentrated in discrete shear zones / high strain areas where mineralizing fluids have been focused into areas of increased permeability. High-grade lenses vary in thickness from only a couple of metres up to 20 m wide and sit within a broader zone of lower-grade mineralization which can extend up to 100 m from the sheared contact with the arenite sediments. High-grade lenses within the broader low-grade region are characterized by a notable increase in alteration / silicification. High-grade zones may also exhibit to some degree a sigmoidal form in sections where higher grades are thicker, and steeper-dipping mineralized regions become thinner and more flattened as you progress up and down the dip.
Gold is associated with pyrite veinlets and quartz–sericite alteration. Chloritic alteration is strong within the core of the ductile shears and as a widespread saussuritic halo affecting the biotite and amphibole mafic minerals, together with carbonate alteration of the feldspars.
Extensive silicification plus or minus chalcopyrite is noted in higher-grade gold zones. Geochemical analyses of mineralized lenses highlighting gold mineralization is associated with an increase in Ag, Cu, Pb and S values with a corresponding decrease in Ca, Na, Al, Li and Sr values.
The hydrothermal paragenesis, chlorite–pyrite coexistence, temperature of ore formation, and sulfur isotope evidence indicate relatively reduced fO2 conditions for the mineralizing fluid. Mineralizing fluids have been interpreted as having a metamorphic origin (Klein, 2014).
Chega Tudo
Gold is associated with quartz sericite pyrite alteration that is generally conformable to the N40W, 80-90 SW foliation trend of the shear zone. Typically, mineralization forms en echelon pods elongated with the shear foliation and persisting for tens to hundreds of metres of strike and a similar distance down dip. These northwest-trending, steeply southwest-dipping mineralized zones range from a few metres to as much as 30 m in width and can form multiple pods that can be several hundred metres in length.