The Yarawindah Brook Project is an early stage, underexplored Nickel-Copper-Cobalt project.
· Exploration demonstrates potential for high-grade, massive Ni-Cu sulphide mineralisation at shallow depths
· Multiple, distinct, mineralised mafic-ultramafic intrusions within the Project, open at depth and along strike
· Emerging Ni-Cu-PGE sulphide province
Yarawindah Brook is located 130km northeast of Perth, in agricultural land near the township of New Norcia. The Project has had only limited nickel, copper and cobalt exploration despite a favourable regional setting, prospective geology and near-surface occurrences of nickel and copper mineralisation. Historical exploration has focussed primarily on a small platinum and palladium (PGE’s) resource which the Company views as a “path-finder” anomaly for ¬¬massive nickel-copper-cobalt sulphides.
Previous drilling in 2007 targeting surface EM anomalies, returned encouraging results from hole YWRC0083 including 7m @ 1.30% Ni, 0.22% Cu, 0.06% Co and 432ppb Pd from 74m. Despite the promising result no further follow-up drilling was conducted due to budget limitations of the previous operator during the exploration downturn post-GFC.
Cassini completed an airborne electromagnetic survey (AEM) over the project in early 2018, identifying numerous conductors worthy of further investigation. A surface fixed loop electromagnetic (FLEM) survey was completed over several of the higher priority AEM anomalies in order to confirm and better constrain the conductors prior to drilling. The FLEM reinforced the XC05 (Brassica) and XC06 anomalies as priority targets as well as the AN01 and AN02 (Avena) conductors at the southern end of the main Yarawindah Prospect (Figure 1).
The Company completed its first diamond drilling program in early 2020, targeting multiple electromagnetic (EM) conductors identified following the airborne and ground EM surveys of 2018. A total of 9 diamond holes were completed for 1,148m.
Cassini’s latest drilling campaign tested new electromagnetic (EM) conductors at the Brassica Prospect, and extensions of the sulphide mineralisation defined at the Avena Prospect. The Avena Prospect is located at the southern end of the Yarawindah Intrusion which has been the focus of historical exploration, where prior efforts primarily focused on the supergene PGE mineralisation.
At Avena, drill holes have predominantly intersected broad zones of shallow, disseminated Ni and Cu sulphides, and locally contain high-grade, massive nickel sulphides. The Company is particularly encouraged by a massive sulphide intercept of 0.12m @ 5.97% Ni, 0.75% Cu, 0.39% Co & 2.66g/t PGE from 84.3m in YAD0005. Nickel tenor of this intercept is representative of the historical massive sulphide intersections at Yarawindah, which are the Company’s primary targets. Although thin, this interval is interpreted to represent a structurally remobilised massive sulphide from a proximal source. Further encouragement was returned from YAD0006, which intersected 5.05m @ 0.69% Ni, 1.17% Cu & 0.06% Co from 57.95m. These intercepts range from 50m to 72m vertically below surface, well within open-pit mining depths.
Mineralisation remains open along strike and down-plunge to the north. Downhole electromagnetic survey (DHEM) has identified new “off-hole” conductors, which are yet to be fully integrated into our geological interpretation at Avena.
At the Brassica Prospect, YAD0003 intersected a 70m zone of metagabbro with thick zones of disseminated and locally semi-massive zones of barren iron sulphides (pyrrhotite) and trace Cu sulphides (chalcopyrite) thus reflecting low tenor Ni and Cu sulphide mineralisation. Nonetheless, the metagabbro sequence is very similar to those along strike at Brassica that returned promising intercepts of 1.1m @ 0.50% Ni, 0.10% Cu & 0.08% Co from 92.9m in YAD0002 and 0.7m @ 0.09% Ni, 1.46% Cu & 0.02% Co from 71.4m in YAD0001.
The results to date at the Avena and Brassica Prospects support the Company’s exploration model that the Yarawindah Project has potential to host multiple Ni-Cu magmatic sulphide deposits.
Results from a further three holes (YAD0007 – YAD0009) at the AN01 Conductor are expected shortly. These holes targeted off-hole conductors from historical DHEM and intersected visually encouraging zones of sulphides.
Interpretation of results will continue at the Avena Prospect whilst the Company broadens its review of historical Ni and Cu results that stretch over 3km of strike to the north. A surface fixed loop EM survey has commenced over an area covering approximately 2km x 1.2km, including areas of shallow historical drilling with anomalous Ni, Cu and PGE results.
Concurrently, a soil geochemistry program has begun targeting potential mineralised intrusions beyond the Yarawindah, Avena and Brassica Prospects. Approximately 1,000 samples will be collected in the first-phase using a hand auger to obtain sample below cultivated soil.
The results at the Project to date have demonstrated mineralisation over a broad area, at multiple prospects and validated the Company’s regional targeting model. Future exploration programs will begin to test the regional prospectivity which has had little, if any, modern exploration for Ni and Cu sulphide mineralisation. To this end, the Company has expanded its tenure with two new applications, now covering almost 400km2 (Figure 3).
Cassini views the Yarawindah Project as an excellent opportunity to apply its geological expertise and learnings in nickel-copper systems from the West Musgrave Project to an apparently similar mineralised system with only limited modern exploration. Further, the project is conveniently located adjacent to roads and power, providing development advantages if exploration proves successful.
The project provides Cassini with further exposure to nickel, copper and cobalt, three critical components of advanced technology and a decarbonised future.
For further information on this project, please refer to the ASX Announcements section of the website.