Patriot Lithium Limited (ASX: PAT) continues its exploration in the Black Hills of South Dakota, reporting its recent mapping and sampling program at its Keystone Project has identified two outcropping groups of fractionated pegmatites, lying along a broader 2.5 kilometre and 400 metre wide corridor, which demonstrates the Project’s potential for lithium mineralisation.
Figure 1: Patriot footprint in North America
A 2.5KM Long Pegmatite Corridor
Patriot reported that the completion of its field program identified two outcropping groups of fractionated pegmatites at the Keystone Project, that effectively demonstrate lithium and mineralisation.
The two pegmatite clusters have been named the Big Dog-New Road-Towel Trail pegmatite cluster, and the Tin Hill-Gilt Edge-Rattlesnake pegmatite cluster.
Once identified, the pegmatites were extensively sampled with portable X-ray fluorescence (XRF) and laser-induced breakdown spectroscopy (LIBS) readings which are reported to have returned promising results.
The XRF and LIBS readings suggest the presence of multiple samples characterised by K/Rb ratios ≤30 and elevated spot lithium values reaching up to 683 ppm. Further testing on individual pegmatite outcrops, spanning up to 350 metres in length and 60 metres in width, reveals extensive fractionation, indicating a substantial potential for lithium mineralisation.
The Company reports a total of 145 rock chip samples have been collected at the Keystone Project and sent to the SGS laboratory in Burnaby BC for assaying.
Figure 2: Simplified geological map illustrating the Keystone lithium district showing the location of the newly identified ‘low K/Rb pegmatite corridor’ within PAT’s Keystone Project, Black Hills, South Dakota.
Patriot’s Keystone Project
Patriot’s Keystone Project, wholly owned by the Company, spans approximately 34 square kilometres of lithium-prospective tenements within the prolific high-grade Black Hills Lithium Province.
The strategically positioned claim blocks for the Project are in close proximity to key mines in the region, such as the Etta, Edison, Hugo, and Bob Ingersoll mines, which stand as the largest and most historically significant hardrock lithium producers in the Black Hills.
The Company is confident in the potential of lithium mineralisation at the Project, noting it is located a mere 24 kilometres from Iris Metals’ (ASX: IR1) Beecher Project, which yielded drill intercepts of 60 metres @ 1.21% Li2O and 78 metres @ 1.03% Li2O.
The Mapping Program
The mapping and sampling initiative successfully concluded at the Keystone and Tinton West Projects played a crucial role in verifying existing pegmatites and uncovering new outcropping pegmatites.
In tandem with the 145 rock chip samples gathered from the Keystone Project, an additional 43 rock chip samples were procured from Tinton West and forwarded for assaying.
The Company expects to receive laboratory results in the coming weeks.
The program successfully advanced Patriot’s comprehension of the pegmatites and structures at both Projects. In an integrated perspective, the Big Dog-New Road-Towel Trail and Tin Hill-Gilt Edge-Rattlesnake pegmatite clusters, along with several accompanying smaller pegmatites, collectively constitute a 2.5-kilometre long and 400-metre wide pegmatite corridor oriented in a NNW-SSE direction.
This corridor runs parallel to the regional-scale Silver City Fault and the predominant structural fabric in the area. Patriot intends to prioritise this potentially fertile pegmatite corridor for follow-up soil work at the Project.
Figure 3: Close-up of the newly identified ‘low K/Rb pegmatite corridor.’
Tinton West Project
Patriot’s Tinton West Project straddles the state line between South Dakota and Wyoming, with claim blocks covering an estimated 10 square kilometres of the Tinton Inlier, located in the Black Hills.
Numerous tin-bearing pegmatites, predominantly oriented NNW-SSE, have been identified within Patriot’s Tinton West claims area.
The Sand Creek pegmatite, the most extensive among them, spans 465 metres in length and 30-50 metres in width.
Following sampling and testing using pXRF and LIBS readings, Patriot acknowledges that while the results were not as promising as those from the Keystone Project, the analysis still disclosed K/Rb ratios of ≤100 in three samples and elevated lithium levels in one out of the 10 samples.
Figure 4: Simplified geological map of the Tinton lithium district showing PAT claim blocks and locations of pXRF readings
The Next Steps
From here, the Company awaits assay results which will inform future exploration.
Geophysical methods such as GPR may be employed to image the 3D geometry of the pegmatite intrusions to aid design of drill holes.
Concurrently, Patriot will persist in its environmental study efforts to facilitate the expeditious progression of drilling permitting and approvals.
You can read the full Portable XRF and LIBS readings here.
Patriot Lithium’s CEO and Managing Director Nicholas Vickery commented on the newly identified pegmatites.
“The results from this latest round of mapping and sampling are very encouraging, identifying a 2.5 kilometre long, NNW-SSE-striking corridor defined by a series of highly fractionated pegmatites with individual pegmatite outcrops up to 350 metre-long and 60 metre-wide, and only 3.5 kilometres from historic high-grade mines,” he said.
“While we have not yet confirmed whether these pegmatites are lithium mineralised, the XRF and LIBS readings indicate high degrees of fractionation of pegmatites in this corridor and therefore the potential for lithium mineralisation in the subsurface. We look forward to undertaking further work to help better define this potential and identify drill targets to test.”
PAT’s Australian Stock Exchange-listed share price is currently trading at $0.19 (12.00pm UTC+ 8 hours).