59,000ha located in SE portion of the belt, 60km SW of Anglo American’s Jaca discovery
Excellent infrastructure. Project located adjacent to BR-163 federal highway. Ranch land
Elevated gold (to 172 g/t) and copper (to 0.96%) values on surface. Copper-in-soil anomaly 1.5km in diameter at Gabriel target <308ppm copper
Porphyry-style alteration on surface over several square kilometres. Highly prospective for porphyry copper mineralization
Results pending on reconnaissance drill program
Untested gold and copper soil anomalies associated with outcropping
porphyry-style alteration. Mato Grosso State, Brazil
Background and Copper Potential
The property is characterized by very high-grade gold values in four main areas on surface and widespread anomalous copper values over an area which is extends for 6km E-W.
Porphyry-style alteration has been observed in several areas. The project is located just 60km SW of Anglo American’s recent porphyry copper discovery at Jaca (see map). Anglo American control 2.5M ha within the Alta Floresta belt and both Codelco and Nexa have extensive land positions which were all acquired AFTER Altamira acquired its land position.
Regional map of Alta Floresta Belt. Anglo American staked 2.5M ha in late 2017 following the discovery of the Jaca porphyry copper deposit. Nexa subsequently staked 1M ha and Codelco acquired 0.8Mha. Nexa, Freeport and Rio Tinto are also all reportedly active through farm-ins on third party ground
The property geology consists of Nhandu granite in the southern and central portions, and Colider suite micro-granites in the northern parts. North to northeast trending diabase dykes are in part parallel to a broad NNE trending shear, hosting later brittle deformation, hydrothermal alteration, quartz veining and gold associated with sulphides. Observed thicknesses and gold grades in the saprolite indicate potential for discovery of a significant open pit resource at Santa Helena. Three and six km-scale Au in soil anomalies over a 7 km trend associated with the broad shearing event remain virtually untested. Observed thicknesses and grades within the saprolite oxide domain indicate potential for discovery of an economic open pit deposit.
The project has never been the subject of any previous drilling by Altamira. The current sampling program suggests the presence of a mineralized system with copper and gold values along a distance of 6km E-W.
The most easterly target is the Gabriel area which is located 1.2 km north of a small historic open pit mine which produced gold from a series of high-grade veins. A total of 20 grab samples were collected on surface from this area and returned gold values ranging from 0 to 171.6 g/t gold and 0 – 0.96% Cu and averaged 19.0 g/t gold and 0.11% Cu. Seven samples returned values above 10g/t gold.
The Flecha Dourada target is located 3km WSW of Gabriel. Grab samples from this prospect ranged from 0.3 – 153.8g/t gold and 0 – 0.81% Cu and averaged 31.2g/t gold + 0.13% Cu with 11 samples returning above 10g/t gold.
The Dorival target is located 500m west of Flecha Dourada. Six grab samples were collected from this prospect which ranged from 7.4 to 73.3g/t gold and 0 to 0.27% Cu, and averaged 24.6g/t gold.
Six grab samples were collected from the Tucura area and returned gold values of 0.2 to 22.6 g/t gold and averaged 7.2g/t gold. Tucura is located 2km NW of the Dorival target.
In addition to the rock sample results outlined above, Altamira has completed a program of soil sampling which has identified a significant zone of anomalous copper values which is 1.5km in diameter, with values up to 308ppm copper. Anomalous molybdenum values are also evident on the northern margin of the copper-in-soil anomaly with the zone being open to the north.
In addition, two existing gold-in-soil anomalies identified during previous sampling, are known to exist in the Gabriel and Flecha Dourada areas and appear to be peripheral to the copper-in-soil anomaly at Gabriel. The anomaly in the Gabriel area has a north-east trend and a surface expression of 1000m x 400 meters (gold-in-soil values range from 50 to 3,834 ppb Au). The gold anomaly is located 1km west of the copper-in-soil anomaly. The second gold anomaly is located two kilometers to the south west in the Flecha Dourada area and extends over an area surface of 750 x 500 meters (gold in soil values range from 50 to 3,830 ppb Au).
The presence of a copper-in-soil anomaly at Santa Helena associated with a large-scale hydrothermal alteration system, as well as two significant gold-in-soil anomalies and numerous high-grade gold bearing structures and elevated copper values increases the potential for a concealed Au-Cu mineralized system at Santa Helena.
Satellite image of northern part of Santa Helena project area. Note distribution of copper, gold and molybdenum anomalies and distribution of surface rock samples with anomalous copper values
Satellite image of northern part of Santa Helena project area. Note distribution of copper, gold and molybdenum anomalies and distribution of surface rock samples with high grade gold values
Gold analysis has been conducted by SGS method FAA505 (fire assay of 50g charge), with higher grade samples checked by FAA525. Analytical quality is monitored by certified references and blanks. Until dispatch, samples are stored under the supervision the Company’s exploration office. The samples are couriered to the assay laboratory using a commercial contractor. Pulps are returned to the Company and archived. Drill holes results are quoted as down-hole length weighted intersections