GreenX Metals: Laboratory Analysis of Historical Samples from ARC Confirms up to 99.8% Pure Native Copper
11 August 2022
- Laboratory XRF analysis of native copper samples from the ARC Project in Greenland show high purity consistently over 99% copper
- Analysis also confirmed the presence of silver in one sample, and no significant deleterious elements in any of the three analysed historical samples
- Three native copper samples were collected in an area spanning 30km from the Discovery Zone, Neergaard Dal, and Neergaard South prospects within ARC
- Current field work program now underway, with results to be released as they develop over the coming months
Figure 1: Native copper sample recovered from adjacent to the Discovery Zone in 1994.
GreenX Metals Limited (GreenX or Company) and its joint-venture (JV) partner Greenfields Exploration Ltd (Greenfields) are pleased to announce the results of preliminary analysis on three historical samples of native copper nodules from the ARC Project (ARC or the Project) in Greenland. The samples were obtained from a recently opened government geological storage facility in Copenhagen. Three native copper samples found at Discovery Zone, Neergaard Dal, and Neergaard South within ARC were subject to advanced micro-XRF scanning, a more precise and comprehensive technology when compared to more common portable XRFs. The best analysis result was for a sample found immediately south of the Discovery Zone (Figure 1), which indicated median copper purity of 99.8%, with 255 g/t silver, 0.004% antimony and 0.000% arsenic. The samples from Neergard Dal (Figures 8 & 9) and Neergard South (Figures 11 & 12) indicated copper purity of 99.7% and 99.4% respectively, with low to no deleterious elements detected in any of the samples. The high quality of the analysed samples is comparable to blister copper, a product typically produced by smelting prior to being sent to a refinery.
Dr Jon Bell, Greenfields’ Technical Director commented: “We were confident that the native copper would be rich with low levels of deleterious elements, but we didn’t expect the results to be so spectacular. The non-destructive nature of this methodology means that we can start collecting metallurgical as well as grade information from early in the exploration cycle.”
BACKROUND
In June 2022, the JV was granted access to recently constructed government geological storage facilities in Copenhagen, Denmark. These facilities store multiple historical samples from the ARC Project, largely collected in 1978 and 1979, from an area spanning 30km from the Discovery Zone, Neergaard Dal, and Neergaard South prospects (Figure 2).
Figure 2: Location of native copper samples.
Note: Samples from the Discovery Zone and Neergaard Dal South are from float, but are interpreted to be proximal to the source. The Neergaard Dal fissure breccia is in situ.
Three samples of native copper i.e., near-pure copper metal found in nature, were identified:
- native copper from immediately south of the Discovery Zone prospect (Figures 4 & 5),
- fissure copper from the central Neergaard Dal prospect (Figures 6 to 9), and
- native copper from Neergaard South prospect (Figures 10 to 12).
Notably, the existence of the samples from the Neergaard Dal and Neergaard South prospects was not previously known in the historical data set.
Similarities to Keweenaw Peninsula
The ARC native coppers are of particular interest to the Company, given the potential for them to be geologically analogous to the Keweenaw Peninsula (Michigan, USA). The native copper at Keweenaw was extremely enriched, almost pure, with very little in the way of deleterious elements. Due to the high purity of the historical samples recovered, the Company considers these results to be reminiscent of the Keweenaw mineralisation, and it looks forward to future exploration results to substantiate this indication.
The main by-product element found with the Keweenaw copper was silver, an element that is also recorded in the historical assays from ARC, and the currently analysed Discovery Zone sample (Figure 1) containing 255g/t Ag. Notably, the records of the silver at Keweenaw are incomplete as it is reported that much of it was misappropriated by the miners, giving testament to the silver size and quality. The historical mining companies at Keweenaw were instead focussed on the almost pure native copper, that in some cases weighed hundreds of kilograms. These extreme native copper occurrences were hosted in ‘fissures’ (faults). Significantly, the native copper sample from Neergaard Dal is hosted within a fault, giving the potential for similarly intense mineralisation.
Figure 3: Polished native copper nuggets from Keweenaw, Michigan (USA).
Native copper samples gallery
Figure 4: Native copper sample recovered from immediately south of Discovery Zone copper sulphide prospect in 1994.
Figure 5: The weathered surface was polished by Greenfields to expose the fresh copper/copper-alloy. This exposed surface was used for the micro-XRF analysis.
Figures 6 & 7: Neergaard Dal fissure copper.
Note: The bright copper at the centre of the sample is a result of sawing. The weathered mass of the copper is to the left of the sawed section and expresses as dark/slightly green mass, so the extent of the native copper content is more significant than immediately apparent in the photos.
Figures 8 & 9: Neergaard Dal fissure copper.
Note: The extent of the native copper only becomes visually obvious when cut.
Figure 10: Sample of native copper from Neergaard South not previously known to be in storage.
Figure 11 & 12: (left) Neergaard South sample showing the main mass, as well as the off-cut. (right) A close-up of the cut-off showing a small area polished flat for micro-XRF analysis.
Results of Micro-XRF Analysis
ARC’s mineralisation is thought to be the product of multiple mineralisation events, an early native-copper event and a later copper sulphide event. Understanding the quality of the native copper was the prudent focus of this preliminary analysis. The native copper sample from the Discovery Zone was partially polished and sent to an independent university facility, with the other two samples being sent to a consulting firm for micro-XRF analysis. This advanced technology was used to perform scans within which more focussed point analyses were performed. Like the well-known portable XRF units, micro-XRF units use X-ray fluorescence to analyse the elemental composition of a sample. However, micro-XRF is an order of magnitude more precise than portable XRF and it can also perform scans over much larger areas – giving it a significant advantage in both precision and scale. Micro-XRF is sensitive enough to analyse down 0.025mm, whereas the more portable XRF units are limited to no better than 3.0mm, some 120 times coarser. The result of the scanning is that highly precise elemental maps can be generated (Figures 9 & 10). As a cross-check, a copper alloy-calibrated handheld portable XRF unit was used to perform spot checks. This specially calibrated united produced similar results to the high powered micro-XRF units.
Figures 13 & 14: Imagery from the micro-XRF machine
Note: There is a scale difference between the two images. The isolated area of tarnished native copper is shown figure 13, in the iron (Fe) and sulphur (S) map on the right, figure 14.
This non-destructive technology can give elemental, as well as mineralogical information. To determine the purity of the native copper, only elemental analysis is necessary. The statistics of the scans are shown in Tables 1 to 3 and Figure 16. This information is useful for guiding future, more quantitative work programs focussed on the native copper quality that may include assaying. Additional statistical tables are contained in the Appendices A to C.
FUTURE WORK
The results of the micro-XRF analysis are supportive of the potential quality of the mineralisation at the ARC project and will inform the current field program. The current field program incorporates geochemical sampling, portable core drilling, and geophysics at high-priority targets within ARC. The Discovery Zone, where the highest-purity analysed sample was recovered, is the highest priority exploration target. GreenX expects it will be in the position to release substantial further news flow in relation to this project across the coming months.
ABOUT THE ARCTIC RIFT COPPER PROJECT
ARC is an exploration joint venture between GreenX and Greenfields. GreenX can earn 80% of ARC by spending A$10 M by October 2026. The ARC Project is targeting large scale copper in multiple settings across a 5,774 km2 Special Exploration Licence in eastern North Greenland (Figure 15). The area has been historically underexplored yet is prospective for copper, forming part of the newly identified Kiffaanngissuseq metallogenic province. This province is thought to be analogous to the Keweenaw Peninsula of Michigan, USA, which contained a pre-mining endowment of +7 Mt of copper contained in sulphides and 8.9 Mt of native copper. Like Keweenaw, ARC is known to contain at surface, high-grade copper sulphides, ‘fissure’ native copper, and native copper contained in what were formerly gas bubbles and layers between lava flows.
Figure 15: ARC license area
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Forward Looking Statement
This release may include forward-looking statements, which may be identified by words such as "expects", "anticipates", "believes", "projects", "plans", and similar expressions. These forward-looking statements are based on GreenX’s expectations and beliefs concerning future events. Forward looking statements are necessarily subject to risks, uncertainties and other factors, many of which are outside the control of GreenX, which could cause actual results to differ materially from such statements. There can be no assurance that forward-looking statements will prove to be correct. GreenX makes no undertaking to subsequently update or revise the forward-looking statements made in this release, to reflect the circumstances or events after the date of that release.
Competent Persons Statement
Information in this announcement that relates to Exploration Results is based on information compiled by Dr Jonathan Bell, a Competent Person who is a member of the Australian Institute of Geoscientists. Dr Bell is the Executive Director (Technical) of Greenfields Exploration Limited and holds an indirect interest in performance rights in GreenX. Dr Bell has sufficient experience relevant to the style of mineralisation and type of deposit under consideration and the activity being undertaken, to qualify as a Competent Person as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Dr Bell consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears.
This announcement has been authorised for release by Mr Ben Stoikovich, GreenX CEO.
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