The Brunton Pass Project is located in central Nevada 25km northeast of the high-sulphidation epithermal Paradise Peak gold deposit that produced over 1.6 million ounces of gold and over 44 million ounces of silver and at least 457 tons of mercury.
The project was acquired in 2021 after sampling of prospector small-scale surface workings revealed high copper values. Reconnaissance rock chip sampling and mapping were subsequently carried out throughout the claim block returning values up to 6.84% copper and 1.75 g/t gold in separate samples as well as anomalous silver values.
A drone magnetic and photogrammetric survey was also carried out in 2021 and the data was subsequently processed using magnetic vector inversion modelling.
Mineralisation at Brunton Pass is closely associated with hornfels and skarn alteration of a mixed sequence of Triassic aged carbonate and clastic sediments that form a 1.8km x 0.75km, uplifted “window” (horst block) in fault contact within younger Tertiary-age volcanic rocks. The magnetic inversion model suggests that the Triassic sediments may be underlain at shallow depth by a large intrusive body that could be the source of the alteration and mineralisation. Evidence for this underlying body is found in surface outcrops of granite/granodiorite and at least two phases of diorite intrusion.
Following initial prospecting a total of 485 soil samples were collected at 50m spacing on lines 100m apart over the main window and on a 100m by 100m offset grid over the remainder of the project area.
Several copper-in-soil anomalies with individual grades of up to 953ppm copper were delineated based on this sampling. The largest of these anomalies in the southwest quadrant of the property has dimensions of 340m x 310m and they are mainly coincident with areas where rock grab samples contain percent-level copper values in small prospecting pits.
Two large mercury and arsenic in soil anomalies were also defined in the eastern half of the property in a north trending zone with values up to 52 ppm mercury with the largest of these extending over an area approximately 500m x 500m. These anomalies are centred on a north trending zone of structural dislocation with a strike length of at least 1.2km entirely within the project area.
In summer 2022 a programme of trenching, sampling, geochemical analysis, petrological evaluation and field follow up was carried out.
Six trenches (T1, T2, T7, T8, T10 and T11) were completed for a combined length of 386m to further evaluate previously reported copper, mercury and arsenic anomalies in soil and surface rock chip samples.
Copper Targets
Gold Target
The argillic alteration evident in T1 and T11 is similar to that seen at the Paradise Peak Gold Mine (smectite+quartz+/-opal).
The work undertaken during the 2022 summer season suggest the possible presence of a porphyry copper target and epithermal gold mineralisation at deeper levels.
Drill testing of these copper and gold targets is now warranted.
