Altamira Gold reports encouraging exploration results from Santa Helena Project, Brazil
Altamira Gold Corp. [ALTA-TSXV; EQTRF-OTC; T6UP-FSE] provided an update on its ongoing exploration program for copper and gold at the Santa Helena project in Mato Grosso State, Northern Brazil.
Highlights: The first of four defined copper-in-soil anomalies to be surveyed with ground magnetics at Santa Helena reveals a major regional fault trend and arcuate magnetic features, consistent with hydrothermal alteration associated with a porphyry intrusive-type setting.
The 600 x 200-metre core of the copper-in-soil geochemical anomaly has a coherent zone in excess of 300ppm Cu and a peak value of 448ppm Cu, against a background of ~40ppm Cu. The anomaly has dimensions and a style that are consistent with a porphyry geochemical footprint. Stockwork quartz veining was exposed in a single trench excavated to date within the soil anomaly.
Previous scout drilling for gold targets 600m to the south-west of the copper anomaly showed deep weathering effects to a vertical depth of 50 metres, potentially leaching base metals.
The copper-in-soil features have associated NE/SW trending gold vein occurrences on their periphery. Scout drilling of these gold vein systems has identified porphyry style alteration and stockwork veining in intrusive wall-rocks to these structures. Both molybdenite and chalcopyrite have been identified in these veins.
CEO Mike Bennett commented: “The recently completed ground magnetic survey at Santa Helena has strengthened our belief that this target has strong potential for porphyry-related copper mineralization. The prospect forms part of a regionally zoned copper and gold intrusive system and will be our first test of the copper potential in the Santa Helena area. We now have coincident geochemistry and a major structure, plus evidence of porphyry-style alteration and porphyritic intrusives in close proximity to this target, from our prior drilling. This is one of four copper-in-soil anomalies that we are testing with ground geophysics to define scout drilling targets and we look forward to drill testing these anomalies in the near future.”
The Santa Helena project is located immediately adjacent to the paved BR-163 federal highway in the state of Mato Grosso and 60km SW of the Jaca porphyry copper deposit which was recently discovered by Anglo American plc.
There is no history of copper production in the Santa Helena area and previous artisanal mining activity has focused on high-grade gold, hosted in vein structures.
A ground magnetic survey has been conducted over this north-eastern copper-in-soil anomaly using survey lines oriented north-south, separated by 50 metres and with readings every second at walking pace. The data was quality controlled and analyzed by consultant geophysicist Mat Cooper of Core Geophysics Western Australia.
A trench excavated in the western end of the main soil anomaly showed vein and stockwork structures in saprolite and returned 41 metres of 397ppm Cu. Leaching in the surficial environment is common and values in soils or trenches may be significantly depleted in base metals.
Prior drilling around the artisanal gold working (garimpo) to the south-west of the magnetic and copper-in-soil anomaly has shown at least three different generations of veining in drill core, indicating an alteration system that was reactivated in different temperature regimes, currently interpreted as reflecting the distal part of a cooling hydrothermal system associated with a local (porphyry) intrusion.
Altamira is in the process of completing ground magnetic surveys over the other three defined copper-in-soil anomalies and plans to accelerate the definition of drill targets for scout diamond drilling.
The company is focused on the exploration and development of gold projects within western central Brazil. Altamira holds six projects comprising approximately 190,000 hectares, within the prolific Juruena gold belt which historically produced an estimated 7 to 10Moz of placer gold.
The company’s advanced Cajueiro project has NI 43-101 resources of 5.66Mt of 1.02 g/t gold for a total of 185,000 oz in the Indicated Resource category and 12.66Mt os 1.26 g/t gold for a total of 515,000oz in the Inferred Resource category.