Caspin Resources Limited (ASX: CPN) has discovered a new PGE prospect at the Yarawindah Brook PGE-Ni-Cu Project in Western Australia, only 100km north of Perth.
The prospect, now known as Vicia, is located at the northern margin of the Yarabrook Intrusion and adjacent to the new Serradella discovery where the company has recently reported high-grade and broad widths of PGE mineralisation, along with high-grade rhodium mineralisation.
New PGE discovery – Vicia Prospect
The company completed six RC drill holes on approximately 250m centres, over a large PGE soil geochemical anomaly with dimensions of 900m by 600m. The anomaly is located at the northern margin of the Yarabrook Intrusion, northwest of the Central Yarabrook Prospect, west of the Serradella discovery and structurally below (on the western side of) the Radio Tower Thrust.
Several of the drill holes have returned significant values of PGEs. Better results include:
These two holes are located approximately 250m apart and are open along strike. The results are excellent for a first pass test of the soil anomaly, but more importantly, this is the first intersection of mineralisation beneath the Radio Tower Thrust, which was previously thought to be the footwall boundary to the mineralised package at Yarawindah; demonstrating how the mineralisation potential of the Yarabrook Intrusion continues to grow.
Mineralisation occurs over a strike length of at least 600m with at least two PGE-mineralised lenses. Anomalous PGE results were received from all holes at surface, supporting the original soil anomaly.
The Vicia Prospect lies immediately west of the Serradella discovery and possibly represents a thrust slice of the same broad mineralised system from beneath the Radio Tower Fault, which was previously considered to host only barren gabbroic rocks.
Therefore, these intersections have opened a new exploration search space and demonstrate the potential for further zones of mineralisation to be discovered where there has been no systematic drill testing, including deeper beneath Serradella.
These first pass results at Vicia further emphasise the more prospective nature of the northern margin of the Yarabrook Intrusion, following the excellent results received to date from Serradella.
Further infill and step-out drilling will be conducted at Vicia during the coming field campaign to determine the potential for economic bodies of mineralisation.
Recent results also include drill hole YARC0035, the northern-most hole at Serradella by approximately 500m. This hole intersected a thick sequence of undifferentiated felsic metasediments before passing into mafic lithologies at approximately 170m to the end of hole. The hole has confirmed that the Yarabrook Intrusion plunges northwards underneath lithological cover and supports the Company’s targeting of deeper mineralisation at Lower Serradella.
A demonstration of the effectiveness of soil geochemistry programmes
The Northwest geochemical anomaly was identified during systematic sampling programmes in early 2021 with peak values of 23ppb Pd, 25ppb Pt (background approximately 1ppb each for both Pd & Pt), 513ppm Ni and 662ppm Cu. The anomaly was elevated to a drill target once the gravity gradiometry survey confirmed it was located over a part of the Yarabrook Intrusion, albeit a part of the intrusion that had not previously shown evidence of mineralisation.
The company conducts systematic soil geochemical sampling routinely as a first-pass exploration tool. So far, these programs have identified numerous soil anomalies throughout the Yarawindah Brook Project, most of which are waiting for further infill sampling to evaluate the need for drill testing. These anomalies include Anomaly A & B, Yenart and multiple anomalies along the Brassica Shear Zone.
Of particular interest is a sinuous PGE soil anomaly stretching over three km north of Serradella, which appears to align with the extension of the Hanging Wall Shear into the country rock surrounding the Yarabrook Intrusion. This anomaly appears to be the surface expression of mineralisation remobilised along the shear zone from deep within the Yarabrook Intrusion and would indicate that mineralisation continues extensively beyond what has already been defined at Serradella and again points to the large scale of the Yarabrook Intrusion.
The Yenart anomaly is also interesting because it is coincident with a discrete magnetic anomaly that may represent prospective ultramafic host rocks.
This is a real bonus to what was already a very successful drilling campaign. There are two key positive developments,” Chief Executive Officer, Greg Miles, said.
“Firstly, we previously thought the intrusion west of the Radio Tower Fault, comprising approximately 60% of the Yarabrook Intrusion, was completely barren. This is clearly not the case and opens another future exploration front.
“Secondly, our soil geochemistry program is working extremely well to identify new bodies of mineralisation. This bodes well for the large number of anomalies that have already been identified and waiting further exploration. One of those anomalies coincides with approximately three km of the Hanging Wall Shear north of Serradella, suggesting mineralisation is continuous for a considerable distance down plunge from the mineralisation already discovered at surface.
“These results are another demonstration of the scale of the opportunity at Yarawindah Brook. The Yarabrook Intrusion is developing into a very large mineralised intrusive complex, with over 4km of strike and exceptional prospects for further economic discoveries. We’re looking forward to the recommencement of drilling, starting at Serradella, in the coming weeks.”
The company’s understanding of the mobility of PGE and base metals in this highly weathered and leached environment is still at an early stage of understanding. The interpretation of anomalies will be further refined over time as additional datasets, such as geology and geophysics, are refined and built into the company’s targeting models.
Next Steps
The company is about to recommence drilling at the Yarawindah Brook Project with an extensive programme planned over the summer months. Whilst the immediate focus of the drill program will be on defining high- grade mineralisation at the new Serradella discovery, the program will now also include further drilling at the adjacent Vicia Prospect to evaluate the extent of the new lenses and determine the potential for economic zones of mineralisation.
In addition, aircore drilling is continuing at the Mount Squires Project and is expected to be completed in mid- November.
Soil geochemistry programmes will also continue during the upcoming field season once crop harvest has been completed. There are several anomalies that require infill sampling prior to potential drill testing as well as new areas yet to be covered by first-pass sampling.