Tag Archives: Black Earth Fault

GreenX Metals Ltd #GRX (GreenX or the Company) and its joint-venture (JV) partner Greenfields Exploration Ltd (Greenfields) are pleased to announce the results from the first site visit to the Arctic Rift Copper Project (ARC) in Greenland.  The results of this work program have demonstrated the high-grade nature of the known copper sulphide mineralization, and wider copper mineralization in fault hosted Black Earth zones and adjacent sandstone units. The exact position of a native copper fissure at the Neergaard Dal prospect was also identified. This new information is key to future targeting of stratabound copper of both types.

Highlights:

The field team completed a site visit to the Discovery Zone and Neergaard Dal prospects in the northern half of ARC.

A sample at the Discovery Zone prospect yielded a peak reading of 53.8% Cu with 1,074 g/t Ag; and an average reading of 39.3% Cu and 1,065 g/t Ag (refer to Appendix 1). Other samples at the Discovery Zone yielded 12.09% Cu and 373 g/t Ag; with a median result of some being 5.82% Cu and 448 g/t Ag.

One of the objectives of the site visit was to verify the Discovery Zone, given the extremely high grades reported historically. The location of the high-grade material was apparent from over 150m altitude and on the ground. Finding the native copper mineralisation at Neergaard Dal was similarly easy. Historically, a copper fissure was noted but this was recorded prior to GPS and so the exact location was unknown. A well-mineralised fissure was quickly identified, which bodes well for finding additional fissures in this area and further afield. Portable XRF (pXRF) readings were taken of the collected samples. These results are summarized below and presented in Appendix 1.

Dr Bell, Project Leader said: “The historically reported high grade copper sulphides and fissure copper were located with relative ease during the site visit. Both were immediately apparent on the first pass flying over the sites.  The ease with which the historically reported mineralisation was identified in the field bodes well for in terms of forward work programs to locate and map stratabound mineralisation that may have bulk tonnage potential.”

DISCOVERY ZONE

Samples were collected from the Discovery Zone fault-hosted ‘Black Earth’ and sandstone-hosted mineralisation.          Historical sampling from this area demonstrates 4.5m true width of 2.15% Cu, 35.5   g/t Ag (see the Company’s news release dated 6 October, 2021).  The dominant copper mineral is chalcocite, which occurs as pervasive thin veins that sometimes produce visually obvious green oxides like malachite.  The primary trend of the mineralisation appears to be bounded by a sub-vertical sandstone fault that produces a prominent ~2m ledge (5). As the mineralised fault is softer than the sandstone, it has a negative relief and is superficially obscured in places.

The Black Earth material comprises a variety of different rock types hosted by fine-grained material.  There appear to be at least four subtly different sandstones and mudstones, as well as fragments of very dense, almost complete chalcocite.  This dense material is almost the same as that is historically reported to grade 53.8% copper (‘Cu’) and 2,480 silver (‘Ag’). A handheld XRF unit was used to conduct multiple scans of sample A1199a, which also yielded a peak reading of 53.8% Cu with 1,074 g/t Ag; and average reading of 39.3% Cu and 1,065 g/t Ag (6).  This high-grade sample was recovered from 35m along strike to the west of where a similar grading float sample was historically collected.  The Company cautions that pXRF readings are indicative and not absolute. It is possible that surface oxidation and contamination produced lower readings than may be recorded from the central mass of A1199a. The shape of sample A1199a is suggestive of something tabular, like that of the historical sample with extreme grades.  This tabular shape could result from a vein, like the fine-grained chalcocite veinlets seen throughout the area or a layer within the sedimentary horizon.  Notably, the other Black Earth material hosting this high-grade material is also mineralised, as is the surrounding sandstone. The median XRF reading of the six fragments (A1199a to A1199f) is 12.09% Cu and 373 g/t Ag; and the median of all the 49 Black Earth readings (including A1197a-d, A1198a-d) is 5.48% Cu and 89 g/t Ag.  The samples 1197 and 1198 are of interest as they are from an area where the Black Earth is well exposed, and has an apparent width around 5 m.

In addition to an analysis of the largest clasts above from the Black Earth samples that were washed cleaned, XRF readings were taken directly of the material inside the sample bag.  Visually, this material is dominated by loose, individual quartz grains, and grey clay (7) and was expected to give very low copper and silver readings.  However, seven XRF readings of sample A1199a indicate that the fine-grained material has a median grade of 5.82% Cu and 448 g/t Ag. As this fine-grained material coats all the larger grains, the Company interprets that there is chalcocite within the clays.  Similarly, the median XRF readings of all the fines (not just clay-rich material) is 4.86% Cu, 124.5 g/t Ag. This is important as it means that significant mineralisation is present in all the apparent size fractions, which may reduce any ‘nugget effect’ of the clasts in the Black Earth. The Company will undertake further analysis to assess the distribution of copper and silver throughout the various size fractions of the Black Earth material.

The sandstone flanking the fault that hosts the Black Earth is also mineralised.  Samples from this material show veins and veinlets of chalcocite that lead to prominent malachite stains.  In some instances, the veins are millimetres thick (8), but often they are thinner and more pervasive throughout zones in the rock mass (9).  This extends the search space for copper mineralisation to the outside of the immediate area of the fault zone.

NEERGAARD DAL

The fissure investigated by the Company at Neergaard Dal is one of several fissures reported in the area.  The fissure is estimated to be around 20m thick and strikes in a north-south orientation.  The fissure is well mineralised in the western half, with native copper and cuprite.  The investigated area also exposes a portion of what may be the ‘Red Marker’ (historically called the Red Flow).  A sketch from the year 1979 shows that a fissure extends vertically from a stratigraphic position above the Red Marker, topographically higher than that observed by the Company.  At surface, this gives the fissure more than 200m vertical extent and a strike of more than 600m.  By comparing the position of the Red Marker, the Company also identifies the stratabound “copper-containing gas cavities” is exposed in the southern slope of the same valley. Such stratabound ‘amygdaloidal’ mineralisation contained significant tonnages of copper in other regions such as Keweenaw, USA.  This will be verified as a priority in future field programs.

Samples collected from the newly located fissure at Neergaard Dal weighed up to ~ 10kg.  The samples were collected from scree that derived from the fissure. The western margin of the scree contains extensive, largely disseminated copper mineralisation.  The visually dominant copper mineral is cuprite which coats the native copper.  The samples collected by the Company contain pervasive fine-grained, sub-millimetre cuprite, and more occasional millimetre-scale grains with unaltered native copper at their core.  In turn, the cuprite is associated with haloes of malachite, making the mineralisation visually distinctive in the field.  The pXRF analysis of the most westerly, and mineralised samples (A1196b, c) resulted in median readings of 4.78% Cu and 5.0 g/t Ag; and 1.44% Cu and 7.0 g/t Ag.

LOGISTICS

The main thrust of the 2022 site visit was to establish a logistical base in Greenland. The Company successfully established depots, and field trialed the Sherp vehicles and advanced satellite communications systems.  However, the expansion of war in Ukraine directly impacted and exacerbated the worst global logistical framework in 75 years and this was further compounded by the densest sea-ice conditions in thirty years. Accordingly, much of this field season’s planned geological work has been deferred until the next field season.  However, having the explorations assets already in Greenland will benefit and expedite the next field program at ARC.

ABOUT THE ARCTIC RIFT COPPER PROJECT

ARC is an exploration joint venture between GreenX and Greenfields. GreenX can earn up to 80% by spending a total of 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. It sits within the newly identified, and underexplored Kiffaanngissuseq metallogenic province.  This province is considered analogous to the Keweenaw Peninsula of Michigan, USA, which contained a pre-mining endowment of +7 Mt of copper in sulphides and 8.9 Mt of native copper.  Like Keweenaw, ARC contains, high-grade copper sulphides, ‘fissure’ native copper, and native copper contained in what were formerly gas bubbles and layers between lava flows.

-ENDS-

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 (AIG).  Dr Bell is the Managing Director of Greenfields Exploration Limited and holds an indirect interest in performance rights in GreenX. Dr Bell has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to 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.

To view this announcement in full, including all illustrations, figures and notes, please refer to www.greenxmetals.com.