Chalice Mining Limited (ASX: CHN) has receive significant new results from ongoing regional reconnaissance exploration activities at its 100%-owned Julimar Nickel-Copper-Platinum Group Element (PGE) Project, located ~70km north-east of Perth in Western Australia.
A first-pass ground Moving Loop Electromagnetic (MLEM) survey has now been completed over the ~6.5km long Hartog airborne EM (AEM) target, located directly north of the Gonneville discovery.
The survey over Hartog has defined a cluster of 29 low to moderate conductance, mid to late-time bedrock EM conductors interpreted to be potentially significant Ni-Cu-PGE targets, of similar aerial extent and range of conductance to those at the Gonneville discovery immediately to the south.
Most of the MLEM conductors (A1-G6) occur within a ~6.5km long, 1-2km wide corridor that extends directly north from Gonneville, although four conductors (Hartog East 1-4) are located to the north and north-east of the main corridor and appear to define a new trend.
Managing Director, Alex Dorsch, said there is no outcropping bedrock geology over this broad area of MLEM anomalism that would allow for an initial geological assessment of the source of the conductors; however, the distribution and orientation of the MLEM conductors appears to be consistent with the results obtained over the Gonneville discovery, where MLEM surveys conducted prior to the discovery identified a series of sub-parallel, moderately west- dipping conductors extending over up to ~1km of strike.
EM conductors corresponding to the mineralised zones at Gonneville have typically been in the order of 200-2,500 Siemens. Importantly, only one of the initial eight MLEM conductors at Gonneville was shown to be associated with barren sulphidic sediments. The other seven conductors were associated with zones ofNi-Cu-PGE mineralisation. The new conductors at Hartog have a similar conductance, ranging from ~100 to 3,750 Siemens.
Surface soil sampling at Hartog was also completed as a first-pass screening technique to assess and prioritise MLEM conductors. Soil samples were collected by hand on 200m x 100m and 400m x 200m spaced grids to facilitate rapid sample collection and to minimise environmental disturbance.
Soil sampling at Hartog has outlined extensive areas of moderately anomalous nickel, copper and/or palladium, both coincident with and proximal to the new MLEM conductors and similar to the results generated over Gonneville prior to its discovery.
A strong and coherent chrome anomaly (>700ppm Cr) has also been identified central to the Ni, Cu and Pd soil anomalies, and is interpreted to indicate that prospective ultramafic (pyroxenite) geology extends north from Gonneville through Hartog.
The southern coincident Cu-Ni-Cr anomaly overlies the Hartog East #3 and #4 MLEM conductors, which are considered to be high-priority drill targets. The northern coincident Cu-Pd-Cr soil anomaly remains open to the north, with further soil geochemical results pending. All new soil anomalies and MLEM conductors at Hartog are untested by drilling.
Mr Dorsch said that given the inherent difficulties with sampling a consistent part of the regolith profile, the results are considered to be highly encouraging and the lack of a soil geochemical response over certain MLEM conductors is not considered to have downgraded those targets given very weak to absent soil anomalism over known high-grade mineralisation at Gonneville itself.
Platinum and gold anomalism in soils at Hartog was relatively weak, as they were at Gonneville, and samples were not assayed for other PGEs (Rh, Ir, Os, Ru).
Based on the results of the initial MLEM survey, additional surveying is underway to expand and infill geophysical coverage to approximately 200m spaced lines across the Hartog Target. This program aims to define drill-ready targets and is anticipated to be completed by mid-April.
First-pass surface soil sampling is also underway to the north of Hartog, along the remainder of the ~26km long Julimar Complex, including the Baudin and Jansz AEM targets where historical rock-chip and stream sediment sampling identified Ni, Cu and Pd anomalism.
Once drill targets are finalised, a second approval will be sought from the relevant State Government departments to allow first-pass drill testing, anticipated to occur in Q3 2021.
Concurrently, seven rigs (three Reverse Circulation and four diamond) are continuing the ~160,000m step- out and resource definition drill programme at the ~1.6km x >0.8km Gonneville Intrusion.
Initial reconnaissance exploration activities along the ~26km long Julimar Complex to the north of our Gonneville discovery have delivered exciting results, with a significant number of EM-soil targets already defined at the highest priority Hartog Target,” Mr Dorsch said.
“The identification of discrete EM conductors together with extensive nickel-copper soil anomalies highlights the significant potential of this area to deliver further growth at Julimar directly along strike to the north of where we have a major resource drill-out underway.
“Soil sampling and ground EM at Gonneville guided us to the initial discovery and we are very encouraged to see similar early results at Hartog. We are also pleased that our first regional field exploration program has validated the results generated by the airborne EM survey flown last year, which is a positive sign for our ongoing exploration of the broader district.
“Meanwhile, we have stepped up drilling activities again at Gonneville, with seven rigs now drilling prioritising definition and expansion of high-grade mineralised zones. Initial resource and pit-shell modelling is also being undertaken concurrently, which is guiding our drill pattern.”