Available for joint venture, drill ready subject to permitting
Overview Low sulphidation epithermal vein system exposed over a 2.5km by 50-100m area. Potential to host an epithermal Au-Ag deposit,
430 hectare concession, acquired by staking, in northwest Chihuahua close to the border with Sonora
Classic low sulphidation epithermal banded veins
Veining trends northwest and is hosted primarily by a rhyolite package, interpreted to be a vertical dyke or dome
Fluid inclusion temperatures of 150-200℃ indicate that the veining exposed at surface is high level, perhaps 150-200m above the epithermal productive zone
Sampling at surface has returned gold up to 1.94 g/t and silver up to 34.9 g/t
No community or security issues
The property is located in the Sierra Madre Occidental, very close to the Hermosillo-Chuhuahua highway. Access is from Hermosillo or Chihuahua, about a 7-8 hour drive on paved high way followed by 10km on a good gravel road. The closest town with services is Yecora in Sonora, about 40 minutes (17km) away.
The Bermudez project is located near the Mulatos mine in Sonora, and close to the Dolores mine in Chihuahua. Prospero has found a few small pits at Bermudez but no evidence of systematic mining or exploration.
The land is Ejito owned and permission would be needed from the Ejito before drilling could be carried out.
Prospero's claims cover a system of NW-SE striking veins approximately 2 kilometers in length with over 4.5km of strike length of individual veins. The veins, which are up to several meters wide, consist of multistage banded crystalline and amorphous silica, and platy calcite replaced by silica.
Geology and sampling
The Bermudez vein system is hosted along the margins of a rhyolitic dike complex which is emplaced in andesitic flows and tuffs of the lower part of the Upper Volcanic Series which hosts a number of similar deposits in the region such as Pinos Altos, Concheño, and Ocampo. The veins pinch and swell along strike and exhibit wallrock silicification with stockwork veining up to 40 meters in width.
The structural control at Bermudez consists of a well defined N30°W to N50°W fault system dipping 60° to 80° NE, and a subsidiary N-S to N20°E set of splits in the footwall and hanging wall related to a dextral trans-tensional structural system (Figure 1). A system of felsitic to quartz porphyry dikes is emplaced into the fault system, as well as a low sulfidation epithermal vein system consisting of multibanded quartz, predominantly cryptocrystalline silica phases, and pseudomorphed platy calcite. An unaltered post-vein system of andesitic to basaltic volcanics covers the system to the north.
A total of 144 channel and chip samples have been collected from the epithermal veins, with a best result to date of 1.94g/t Au. The sampling results define strongly anomalous Au, Ag, Ba, and Zn. Fifteen samples show Au values between 0.15 to 1.94 ppm (Figure 2); sixteen samples show silver values between 5 to 35 ppm (Figure 3) and eight samples have Zn values between 50 to 155 ppm. The highest geochemistry was obtained in bands of greenish silica, as well as in the hanging wall of the main veins where greenish silica clasts are cemented by a reddish oxidized silica matrix.
Fluid Inclusion Petrography
Prospero's work suggests that the outcropping veins at Bermudez are roughly 150m to 200m vertically above the epithermal "productive" zone. Fluid inclusion temperature data (153°C to 224°C and salinities between 0 wt% and 3.2 wt% NaCl equivalent) indicate that the current surface expression of the vein system sits between 150m to 280m below the elevation of the now-eroded-off paleo-water table. Most low sulphidation epithermal deposits in Mexico host mineralized zones with temperatures that range from 230°C to 270°C that begin several hundred meters below the paleo-surface. The highest precious metal grades in these deposits typically occur within the middle portion of the ore zones. Prospero's fluid inclusion and geochemical work indicates that drilling at Bermudez should target epithermal mineralization at depths of 200m to 400m below the exposed high level portion the system.
There has been no drilling to date at Bermudez but preliminary diamond drill program has been designed to test the three zones. Approximately 2,000m of drilling should be sufficient initially to test under high level veins and stockworks, assuming PSL is correct in its assumption that the surface is 150-200m above the top of a potential ore horizon.
The estimated cost for the drill program: $260k including water, supplies etc. Additional work would be contingent on the results of first phase drilling.
The target area is claimed with Prospero's "Bermudez 2" claim which covers 430 hectares. The surface lands consist of a parceled ejido with individual owners holding title to their property parcels. The area is friendly to the mining industry given its close proximity to a number of operating mines. It is located within a part of the Sierra Madre Occidental which has no security issues.