Castle Minerals Limited (ASX: CDT) is undertaking further work in an attempt to understand the background of a number of lithium anomalies at its Woodcutters Lithium Project in Western Australia.
A newly completed field validating and rock chip sampling programme has not fully explained the origin of several lithium soil anomalies identified by a recent soil sampling campaign at Woodcutters, which lies between the Bald Hill lithium mine, operated by Alita Resources Limited, and the Buldania lithium deposit owned by Liontown Resources Limited.
Work and sampling spanned a 30 sq. km region and focussed on field checking several recently outlined priority soil anomalies and locating and sampling outcropping pegmatites historically mapped by the GSWA.
A max value of 119.9ppm lithium was obtained from an exposed pegmatite in the vicinity of a Priority 1 soil anomaly but no other pegmatite exposures were identified or able to be sampled to support this as there is considerable obscuring soil cover. No other pegmatites were observed in the vicinity of any of the Priority 2 anomalies.
We are encouraged by the recent rock chip sampling at the Woodcutters Lithium Project which returned lithium anomalism in a pegmatite associated with a priority one soil anomaly,” Managing Director, Stephen Stone, said.
“The lack of any other exposed pegmatites at this priority one target and at the other priority areas to fully account for these anomalies, means that the next phase of work will need to focus on identifying any buried pegmatites that may be present.
“It is now apparent that the anomalous lithium zones are distal to an intrusive centre which is consistent with what would be expected with a fractionated lithium bearing pegmatitic system.
“We remain cognisant that the areas of anomalism occur within the same structural trend as the Alita Resources Ltd owned Bald Hill lithium-tantalum mine, 25km to the north- west.”
A majority of the historically identified GSWA mapped pegmatites, which are not associated with any recently defined priority soil anomalies, were successfully located and sampled. These rock chip samples were also assayed for lithium and associated LCT suite elements (i.e. caesium, tantalum). None returned any anomalism.
“Overall, these latest results from Woodcutters are consistent with what would be expected in a zoned pegmatite field, with little to no fractionation of LCT pegmatites within the granitic host itself transitioning to increased fractionation in the surrounding rocks occurring more distal to the intrusive centre i.e. the areas of priority soil anomalism.
“Whilst generally inconclusive, there is some positivity to be extracted as there is now a guide for the next stage of assessment to vector towards what could be a more prospective region within Castle’s 482 sq. km licence area of which only a very minor part has been assessed.
“The prospectivity for buried lithium bearing pegmatites remains, especially given that the areas of anomalism occur within the same structural trend as the Alita Resources Ltd owned Bald Hill lithium-tantalum mine, 25km to the north- west.”
The next phase of exploration would most likely comprise the use of geophysical techniques such as ground radar, passive seismic and various hyperspectral remote sensing methods along with further mapping, infill soil sampling and follow-up drilling where warranted.
Next Steps
- Design an infill soil sampling programme over the previously outlined anomalies.
- Select appropriate geophysical and remote sensing techniques to locate buried pegmatite bodies, such as ground penetrating radar, passive seismic and hyperspectral satellite imagery.
- Evaluate the several other broad “historical” lithium anomalies in the central part of the Project area. (These are not situated on the interpreted lithium corridor but are still considered to have some prospectivity).
- Plan aircore and RC drill programmes, subject to results, to test specific field verified targets and any exposed pegmatites confirmed to be anomalous in lithium.
