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
Cassini’s 80% owned Yarawindah Brook is located on agricultural land 20km south of the township of New Norcia, 100km northeast of Perth, Western Australia, in the emerging Ni-Cu-PGE sulphide New Norcia province.
The Project is prospective for nickel, copper, cobalt and platinum group elements (namely palladium and platinum). The Company has a significant ground position of over 400km2 in the emerging nickel sulphide province, with the potential of the region demonstrated by Chalice Gold Mines recent high-grade discovery at the Julimar Prospect, approximately 40km south of Yarawindah, within the same mafic/ultramafic intrusive complex (Figure 1).
To date Yarawindah Brook has had 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 focused 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 (YWRC0083). 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 (Ovis) and AN02 (Avena) conductors at the southern end of the main Yarawindah Prospect.
The Company completed its first diamond drilling program in early 2020, targeting multiple new electromagnetic (EM) conductors identified following the airborne and ground EM surveys of 2018. A total of 9 diamond holes were completed for 1,148m.
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 Ovis, all three drill holes targeted electromagnetic conductors and intersected nickel-copper sulphide mineralisation at shallow depths. Best results include 2.25m @ 1.09% Ni, 0.99% Cu, 0.08% Co & 0.24g/t PGE from 84.8m in YAD0008 and 0.9m @ 1.44% Ni, 0.76% Cu, 0.11% Co & 0.19g/t PGE from 86.5m in YAD0009. Mineralisation is hosted in metagabbro and metapyroxenite intrusive sequences, consistent with the exploration model targeting mafic-hosted, orthomagmatic massive sulphides.
The mineralised portion of the host sequence is over 50m thick and anomalous in Ni-Cu throughout, which is important as massive Ni sulphide accumulations are generally associated with large volumes of sulphide-bearing magma. The host sequence in YAD0008 returned an intercept of 50m @ 0.24% Ni & 0.18% Cu (and terminated in mineralised metagabbro) demonstrating the potential scale and prospectivity of the mineralised intrusive.
At the Brassica Prospect, results include 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 (Figure 2). The metagabbro’s are strongly anomalous in Ni and Cu (approx. 500ppm) throughout. 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.
The results to date support the Company’s exploration model that the Yarawindah Project has potential to host multiple Ni-Cu magmatic sulphide deposits. The New Norcia region is deeply weathered, with little fresh rock outcrop and extensively covered by cultivated farmland, which has impeded previous exploration. Despite the presence of known Ni-Cu occurrences, discovered in the 1970s, most historical exploration has focused on surficial bauxite deposits. As a result, there is a paucity of deeper, bedrock drilling and the geology is poorly understood. Cassini has now demonstrated that there is a significant opportunity in the region to apply modern exploration concepts and techniques to identify near-surface, Ni-Cu-PGE sulphide mineralisation.
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.