Lithium, Tin, Molybdenum &
Rare Earth Elements in Newfoundland

Property Description

Caprock has an option to acquire 100% interest in the Ackley lithium-tin-molybdenum-tungsten-REEs property in south-eastern Newfoundland. Ackley comprises 182 claims spread across three separate claim blocks that collectively span an area of 4,550 hectares located less than two hours’ drive from St. John’s. The claim blocks overlie portions of the contact zone of a large Devonian-aged granite complex with Proterozoic metasediments and volcanics, parts of which are “greisened”, or hydrothermally altered, that is similar in age and lithology to the Mount Pleasant deposit in New Brunswick and the East Kemptville deposit in Nova Scotia.

Recent Work

On September 11, 2023, Caprock announced that its technical team had discovered the presence of zinnwaldite, an extraordinary lithium-bearing mineral, during a recently concluded prospecting and sampling program on the Main claim block at its Ackley. Historical work at Ackley returned assays of up to 0.91% lithium oxide, however the specific lithium-bearing mineral was never identified until an internal assessment of recently obtained samples. While it is still early days in our exploration work at Ackley, initial prospecting work indicates a potential for extensive zinnwaldite mineralization on the Property related to the large ‘greisen’ zone that resides at the contact between the Devonian-aged granite complex, and the Proterozoic metasediments and volcanics over which the Ackley claim blocks lie.

Massive zinnwaldite sample taken from Ackley. 

Sample locations

On September 20, 2023, the Company announced high-grade lithium assay results from samples obtained during the initial prospecting and sampling program on the Main claim block at Ackley. Assay highlights are provided in the table below.

These samples were obtained from in-situ zinnwaldite boulders and sub-crop during a first-pass prospecting program in a very small portion of the Main Block called the ‘Deer Pond’ area. Field observations indicate that the sampled zinnwaldite boulders and sub-crop occur in close proximity to the large greisen zone at Deer Pond, however the mineralization appears to be more spatially related to the fine-grained Devonian-aged Ackley granite. This provides Caprock’s technical team a prospective area spanning several square kilometres within the Main claim block where additional lithium-bearing mineralization could be uncovered.

On October 4, 2023, Caprock announced the filing of an NI 43-101 Technical Report for Ackley prepared by ERM Consultants Canada Ltd. (“ERM”) with an effective date of May 31, 2023, thereby designating Ackley as a ‘Property of Merit’. The Company also announced that in addition to the ‘Deer Pond’ area where previously released assay results demonstrated high-grade lithium-bearing zinnwaldite mineralization, its exploration team had identified extensive zinnwaldite mineralization in other parts of the Main claim block. In order to safeguard Caprock’s interests and encapsulate the perceived mineralized trend within the Company’s control, Caprock staked a series of strategically important claims contiguous with the northwestern portion of the Main claim block. 

On November 7, 2023, Caprock announced the results of a high-resolution, drone-based magnetics survey covering the Deer Pond area and its vicinity, that was recently completed at Ackley. The magnetics survey results corroborate Management’s initial field interpretation that Ackley appears to contain a very large zone of greisen alteration which has the potential to host extensive lithium-bearing zinnwaldite mineralization.

           Conclusions from the survey include:

The above figure provides a map of the surveyed area with details of (i) the resulting total field magnetic response from the survey, (ii) lithological interpretation of the magnetic response, and (iii) contextual correlation of survey results with recently sampled high-grade, lithium-bearing zinnwaldite mineralization on surface. 

Additional Info on Zinnwaldite

Zinnwaldite is a potassium-lithium-iron-aluminum-silicate-hydroxide-fluoride phyllosilicate mineral within the mica group that typically occurs in greisens, pegmatites and quartz veins, and is often associated with tin ore deposits. Zinnwaldite is being successfully mined and processed at the Zinnwald Lithium project in Germany, and its presence has only been documented a handful of times in Canada, previously.

In general, zinnwaldite ore is the least energy- and capital-intensive hard rock mining alternative to a lithium-brine operation with respect to the production of lithium hydroxide, especially when compared to spodumene ore. Whereas spodumene concentrate must undergo two separate “high temperature” roast cycles prior to the production of lithium hydroxide, zinnwaldite concentrate only has to undergo a single “medium temperature” roast cycle in order to produce lithium hydroxide.

Additionally, unlike spodumene which has a tendency to lose its lithium content when exposed to ambient weather conditions, zinnwaldite is not subject to weather conditions as a means of production, which allows for greater certainty of supply and control of production.

Historical Work

Limited historical exploration work across the eastern claim block (the “Main claim block”) by companies including Esso Minerals, Rio Algom, American Zinc, Inco and others, discovered occurrences and anomalies of lithium, tin, molybdenum, tungsten and REEs.

Previous magnetometer survey work over part of the Main claim block indicates that the altered contact zone may be extensive, covering several square kilometres, with potential for lithium-bearing micas and pegmatites, and high-grade polymetallic veins. Limited prospect sampling and historical Esso trenches across the Main claim block returned assays of up to 0.91% lithium dioxide, 5.0% molybdenum, 0.67% tin and 1-5% fluorine on surface.

Newfoundland government survey maps of this region report some of the highest lake sediment values for REEs, uranium, fluorine and thorium on the entire island. No significant exploration has taken place at Ackley since the 1980’s, and the Property has never been explored specifically for lithium and REEs until now.