Alliance has two projects in Western Australia’s Eastern Goldfields which are prospective for nickel-copper-gold.
WA Project Locations
Nepean South Nickel-Gold Project, Western Australia (Alliance 100%)
The Nepean South Project is located 26 km southwest of Coolgardie and captures the interpreted southern extension of the ultramafic sequence hosting the Nepean Nickel Mine (now closed). The project is prospective for both komatiitic-hosted nickel sulphide deposits and greenstone-hosted orogenic gold deposits.
Alliance has identified a broad area of gold-in-soil anomalism in the northwest of the auger soil survey area, approximately 4km southwest of the Nepean Mine. The main gold anomaly (>5.5ppb) is approximately 1,100m in length, has a variable width up to 900m and is open the north.
Following a detailed literature review of the existing geological data, it was revealed that historic Metals Exploration percussion hole MLX005 (6,546,600mN / 317,150mE) returned 19.8m @ 0.37 g/t Au from 10.7m to EOH, including 4.6m @ 1.0 g/t Au from 25.9m to EOH.
Alliance completed a 156 sample orientation auger soil survey on three 400m x 50m spaced lines in areas of interpreted shallow transported cover and analysed for gold and base metals. The objective of this orientation survey was to determine the effectiveness of using auger soil sampling as an exploration tool across areas of known ultramafic rock and gold in regolith anomalism, including over MLX005.
Whilst the effectiveness of this sampling technique was variable and no gold in soil anomalism was returned over MLX005 in the east of the survey area, broad gold-in-soil anomalism in the northwest justified a second phase of auger soil sampling to infill the sample spacing to 200m x 50m and extend the survey area to the north (247 samples).
A third phase of auger soil sampling is planned for the first quarter 2017 to infill gold anomalism to a 50 metre by 50 metre spaced grid and extend the survey area to the north with 2 x 200m spaced lines (624 samples).
Subject to results, planned work will consist of aircore drilling to vector towards the primary source of gold.
Nepean South Project: gold-in-soil results on an aeromagnetic image and planned third phase auger soil sampling
Blue diamonds: 0 – 5.5 ppb Au
Yellow diamonds: 5.5 – 10 ppb Au (anomalous)
Red diamonds: > 10 ppb Au (highly anomalous)
Black diamonds: planned Phase 3 auger soil samples
Red line: > 5.5 ppb Au contour
Gundockerta South Nickel-Gold Project, Western Australia (Alliance 100%)
The Gundockerta South Project is located 72 km east of Kalgoorlie and is prospective for both komatiitic-hosted nickel sulphide deposits and greenstone-hosted orogenic gold deposits.
Alliance has completed a detailed literature review of historic exploration within the project area.
Orogenic gold exploration has largely been driven by conceptual structural targeting followed by surface geochemical sampling to test for low level gold anomalism to define targets for drill testing.
CRAE, Mawson, Mt Kersey, Spinifex, North, Yilgarn, Croesus, Heron, and Teck have all completed substantial surface geochemical sampling programs covering most of the tenement.
Compilation of the historic surface geochemical sampling indicates four areas of anomalous gold results have been defined, overlying or adjacent to outcropping Archaean rocks with the tenement.
Past drilling for gold has focussed on testing three of the soil anomalies in the central and eastern parts of the tenement (Targets 2, 3 and 4). Refer Figure 5. No significant gold results were returned from this drilling, with only six holes returning intersections greater than 100 ppb Au associated with ultramafic rocks.
However, there is a large zone of sporadic gold-in-soil anomalism located in the northwest of the tenement area hosted in clay, silt and sand that is approximately 8 kilometres by 3.5 kilometres in size (Target 1).
This target is untested by drilling and overlies a flexure in the interpreted position of the Railway Fault where it truncates mafic and felsic volcanic rocks against younger Penny Dam Conglomerate.
Given the size of this gold anomaly, the surface cover conditions and proximity to a flexure in a major fault truncating rocks of differing rheology contrast, this target has the potential to host primary gold mineralisation.
Future work includes wide spaced drilling to test for gold in regolith anomalism to vector towards primary gold mineralisation.
Past exploration has demonstrated the presence of two main corridors of ultramafic rocks within the tenement area that are considered prospective for nickel sulphide mineralisation.
These ultramafic horizons are strongly magnetic in aeromagnetic imagery and structurally complex, with evidence of fault repetition, displacement, and magnetite destruction. GSWA surface geology mapping within the tenement area has identified olivine cumulate textured peridotite, the favourable host for komatiitic nickel sulphide deposits.
Regional and infill surface geochemical sampling programs completed by CRAE, Mawson, Mt Kersey, North, Croesus, Heron, and Pioneer for nickel anomalism have not proven to be a very effective exploration tool, with anomalous results predominantly related to outcropping and sub-cropping ultramafic rocks. In these areas copper results have generally been low and not indicative of nickel sulphide mineralisation.
Past drilling of the two ultramafic horizons has returned a number of holes with elevated nickel and copper anomalism (+2,000 ppm Ni and +100 ppm Cu) potentially indicating fertile ultramafic rocks, while other holes with +2,000 ppm Ni and low copper results are likely the result of lateritic concentration of nickel.
The most efficient means of exploring for massive nickel sulphide deposits is by utilising electromagnetic (EM) techniques to test for conductors that may be caused by massive sulphide accumulations. No EM surveys have been completed within the tenement to test for conductors potentially related to massive nickel sulphide mineralisation.
Future work may include a moving loop EM survey to test the full strike length of the two ultramafic units, followed by a fixed loop EM survey to better define any conductors prior to bedrock drill testing using RC or diamond drilling.
Gundockerta South Project: CRAE, Mawson, Mt Kersey, Spinifex, North, Yilgarn, Croesus, Heron, and Teck gold in soil sampling results with exploration targets on an aeromagnetic image
Blue diamonds and lines: background gold results
Yellow diamonds: anomalous gold results
Red diamonds: highly anomalous gold results
Magenta ovals: gold exploration target areas