Location, Access and Infrastructure
The Mount Read Cobalt Project areas are located on the Sorrell Peninsular in western Tasmania (Figure 1). The two main prospects comprising the company’s Mount Read Cobalt Project that will be the focus of exploration activity in the first two years of operation ( Figure 2):
Other base metal targets have been defined within the project area but will not be the initial focus of exploration activity.
Figure 1: Mount Read Cobalt Project Location
Figure 2: Mount Read Cobalt Project tenure and location.
Local Geology and Mineralisation
While clearly the geology of the Sorell Peninsular is directly analogous to that of the MRV proper, the exact relationship between the two is a matter of interpretation. The Mount Read Volcanics (MRV) are host to all Western Tasmania’s significant base and precious metal mines and mineral occurrences (Figure 3), several of which have been significant producers of base metals for over 100 years.
The southern extension of the main MRV belt crops out in a N-S trending belt to the east of the Sorell Peninsular, and extends from Mount Darwin, disappearing beneath a Tertiary Graben to re-emerge further south in the D'Aguillar Range area.
Although highly altered, the boninitic rocks of the Timbertops Volcanics exhibit remnant textures, chrome spinel grains with Cr/(Cr+Al) Cr# ~90, and geochemical data similar to other boninitic rocks in western Tasmania.
Geochemically, the Birchs Inlet-Mainwaring volcanic rocks resemble the Miners Ridge basalt from near Queenstown. The Miners Ridge lavas have been interpreted as near the base of the Middle to Late(?) Cambrian andesite-rhyolite succession of the Mount Read Volcanics.
The presence of sheared, serpentinised boninitic, dunitic and rhythmically layered harzburgitic rocks, together with boudins of gabbro, suggests a correlation of rocks within the Pt Hibbs Melange Belt with both the Layered Pyroxenite-Gabbro, and Layered Dunite-Harzburgite successions that form the basement section on which the MRV was deposited elsewhere in Western Tasmania (Figure 3).
Figure 3: Regional Correlation with the Mount Read Volcanics
In 2014, Sherlock Minerals conducted dipole-dipole induced polarisation (IP) surveys for a total of 7.3-line kilometres at the Thomas Creek Project. The IP surveys revealed the presence of a chargeability anomaly approximately (at least) 300 m wide and 500 m long at 100 to 200m depth, that did not appear to have been tested by historical shallow exploration drill holes.
Field reconnaissance visits were undertaken to priority geophysical and geological targets in the Thomas Creek, Henrietta and Hill 99 areas using a portable Niton XRF analyser, with 97 sample readings taken to confirm previous explorer’s results and anomalous areas identified.
Reprocessing and interpretation of historical airborne electromagnetic survey data identified a conductive target within the PHM, ‘Henrietta’, approximately 1.3 km in strike length. Preliminary field investigations at Henrietta located gossanous material with elevated nickel anomalism noted at the easternmost extent of a traverse across the centre of the Henrietta EM target.
In 2015, at Thomas Creek, high-grade copper and gold mineralisation was identified at the surface as a result of follow-up of high-copper values in soils. The mineralisation comprised a massive pyrite zone approximately 5 metres wide, containing abundant copper sulphides hosted within highly weathered saprolitic bedrock, beneath peaty soil cover. Geochemical analyses of the mineralised saprock zone returned values ranging between 0.8% to 3.8% copper, 0.7 g/t to 1.3 g/t gold, and 0.1% to 0.78% cobalt. The mineralisation occurs above the chargeability IP anomaly identified in 2014.
The Thomas Creek intrusive complex is an oval-shaped dioritic intrusive complex. Map relationships (which are not yet precisely established) indicate that the Thomas Creek complex intrudes andesitic lavas and associated volcaniclastic rocks of the Noddy Creek Volcanics, and an adjacent Cambrian lithicwacke-siltstone-conglomerate sequence which may stratigraphically underlie the andesites (Figure 4).
Figure 4 IP Anomalies
panned pyrite-chalcopyrite sulphides + gold from saprock ore
In October 2017 the Thomas Creek site was visited by Accelerate Resources team and collected soil samples. These four samples were submitted to ALS Laboratory Perth for analysis, and the results are presented in Table 1.
Table 1: Soil sample results from the October 2017 field visit
Accelerate plan the following exploration activity in the first two years of operation at Thomas Creek: