Yarawindah Brook Project (80% interest)
- Exciting new PGE-Ni-Cu frontier driven by the success of Chalice Mining at the neighbouring Julimar Project
- Large landholding in the region (>400km) and an early mover into the district
- Encouraging results to date, but less than 5% of the Project effectively explored
- Prospective geology and near-surface occurrences of nickel and copper mineralisation
- Exploration programs already underway, generating new data and targets
The Yarawindah Brook Project is located 100km northeast of Perth, in the emerging PGE-Ni-Cu sulphide New Norcia province. The Project comprises a significant ground position of over 400km2, approximately 40km north from Chalice Mining's recent high-grade Julimar Ni-Cu-PGE discovery.
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 limited deeper, bedrock drilling and the geology is poorly understood. Historical exploration focussed primarily on a small, non-compliant platinum and palladium (PGE) resource which Caspin considers a “path-finder anomaly” for massive nickel-copper-cobalt sulphides, critical components of advanced battery and electrical technology.
Since securing the Yarawindah Brook Project in October 2020, Caspin has completed Stage 1 of a new Airborne Electromagnetic (AEM) survey covering 116km2 that had not been previously explored for orthomagmatic Ni-Cu-PGE mineralisation. The AEM survey identifying 15 new anomalies.
The Company conducted its maiden drilling program at the Yarawindah Brook Project in April-May 2021. The program consisting of approximately 1,000m of diamond drilling at the prospective XC-29 anomaly and PGE target - Yarabrook Hill Prospect.
XC-29 lies on the Brassica Trend, a package of mafic and ultramafic rocks striking over 6km. Results from the three holes completed at XC-29 (YAD0014 – YAD0016) returned anomalous levels of PGE’s, nickel and copper, hosted in primarily sedimentary rocks with minor mafic and ultramafic lithologies. The Company will further assess the data, particularly to understand the stratigraphic position of the sulphide mineralisation, which may provide a vector to mafic-ultramafic hosted Cu-Ni-PGE mineralisation. Anomalous levels of PGE’s are indicative of proximity to a source of orthomagmatic PGE-Ni-Cu mineralisation, providing encouragement for follow up exploration.
Yarabrook Hill is a new PGE target identified after review of historical exploration for sulphide PGE (Platinum Group Elements, primarily palladium and platinum), beneath oxide mineralisation striking over 2km at surface. The Prospect is located 7km north of XC-29 and was the focus of limited PGE exploration during the 1970’s and 1980’s, following the discovery of surficial deposits of palladium and platinum within lateritic rocks. Several drill programs identified supergene mineralisation at shallow depths, but rarely explored deeper than the weathered zone, nominally below 50m vertical depth.
Two diamond drill holes YAD0017 and YAD0018 were completed at Yarabrook Hill. Both holes returned broad zones of anomalous PGE (Platinum Group Elements, primarily palladium and platinum) mineralisation with narrow intercepts of significant palladium, platinum, nickel and copper mineralisation.
Better results were returned from drill hole YAD0017 and include:
- 4.4m @ 0.78g/t PGE (0.52g/t Pd, 0.26g/t Pt), 0.43% Ni & 1.00% Cu from only 66.2m,
- including 0.65m @ 1.93g/t PGE (1.11g/t Pd, 0.82g/t Pt), 1.46% Ni and 1.60% Cu from 67.75m
- 0.2m @ 4.17/g/t PGE (0.95g/t Pd, 3.22g/t Pt), 3.49% Ni & 1.43% Cu from 155.97m
- 9.2m @ 0.74g/t PGE (0.35g/t Pd, 0.39g/t Pt), 0.19% Ni & 0.24% Cu from 300.85m
- including 0.7m @ 4.10g/t PGE (0.77g/t Pd, 3.33g/t Pt), 0.56% Ni & 2.01% Cu from 308.50m
Assays have confirmed the extremely high background PGE content of the Yarabrook Hill intrusion, with the entire interval from 0-311m in YAD0017 averaging >150 ppb PGE. A full list of assay results can be found in Table 1 – ASX Announcement 5 July 2021.
The intensity of mineralisation was observed to generally increase downhole in YAD0017 and was most intense close to the lower contact of the upper, ultramafic section of the intrusion with underlying barren gabbroic rocks at about 310-320m down hole. This defines a prospective stratigraphic horizon that represents a priority target to focus follow-up exploration. Importantly this lower mineralised horizon has not been tested by previous drilling.
In parallel to the Company’s recently completed drilling program, Caspin is undertaking an extensive soil geochemistry program and continues to collect new data sets across the entire project area. First pass sampling was completed on a 400m x 100m grid and infilled to 200m x 100m in prospective areas including Yarabrook Hill.
Sampling to date at Yarabrook Hill has defined a surface palladium anomaly (>6ppb) over at least 3km and beyond the extent of the historical drilling.
Peak values over Yarabrook Hill reach up to 331ppb (or 0.3 g/t). The palladium anomaly is supported by both nickel (>150ppm), copper (>300ppm) and platinum (>6ppb) anomalism, which would be expected overlying PGE-nickel-copper basement mineralisation.
The recent sampling has extended the soil anomalism to the northwest of the recently completed drilling at Yarabrook Hill, with a large coherent PGE-Ni-Cu anomaly extending over a 500m x 500m area. This is potentially a new, previously unrecognised intrusive position which has never been drill tested. Further soil anomalism has also been delineated to the north which also requires further investigation.
The soil survey has also recognised a second PGE-nickel-copper anomaly in a parallel position 500m to the east of Yarabrook Hill, striking over 1.2km. With very limited drilling in this area and no bedrock exposure, the source of the anomaly is unknown, but may represent an upthrown faulted extension of the main intrusion or a separate, unrecognised intrusion.
Further infill samples from the northern extension of Yarabrook Hill have been submitted to the laboratory and assay results remain pending.
The Company has commenced its next drilling campaign, comprising approximately 5,000m of RC, in a staged approach with potential for extensions. The program includes large step-outs between YAD0017 and YAD0018, over approximately 1.25km of strike, as well as targeting the up-dip position closer to surface, where the dip of the intrusion is interpreted to flatten. As more holes are drilled, the Company anticipates being able to vector towards the PGE-rich zones.
Caspin is grateful to have received a co-funded drilling grant through the WA Government Exploration Incentive Scheme to drill the deepest hole at Yarabrook Hill to date which will provide new geological information and another opportunity for discovery.
For further information on the Yarawindah Brook Project please view our latest ASX Announcements.