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Arcadia Minerals Ltd (ASX:AM7, FRA:8OH) (Arcadia or the Company), the diversified exploration company targeting a suite of projects aimed at Tantalum, Lithium, Nickel, Copper and Gold in Namibia, is pleased to announce a geophysical interpretation conducted by the Company’s geologists of the recently completed helicopter borne Electro-Magnetic Survey3.
HIGHLIGHTS
- Interpretation affirms structural concurrence between highly anomalous electro-magnetic zones and mineralised lithium clay pans
- Three stratigraphic boreholes planned by March 2023 to aid exploration. Potential to discover economically mineralised brines not excluded
- Three potentially Lithium-rich brine sub basins identified at Bitterwasser, of which two are associated with the existing Mineral Resource at the Eden Pan and mineralisation at the Madube Pan1,2
- Largest Electromagnetic (EM) anomaly (42km by 9km) is perfectly associated with a major fault structure
- Smaller anomalies are associated with the Eden Basin (8km by 2.5km) and the Madube Basin (5km by 1.5km), both associated with oblique trending tension faults/fractures at depths of around 120 m and high lithium content in the clay pans at surface
- The depth of the large basin based on EM interpretation is up to 200m to the basalt basement with high conductivity from 30m below surface, which is the observed depth of the water table
- Historical water boreholes drilled outside the edges of the main anomaly hold elevated TDS values of >6000 mg/l
Jurie Wessels, the Chairman of Arcadia stated: “The interpretation affirmed our geological model and hypothesis that the Bitterwasser Basin area conforms to the structural requisites of possibly becoming a globally significant Lithium province. From the data it is evident that several entrapment sites were formed through tectonic activity where highly conductive brine fluids could be accumulated. In addition, there is a distinct concurrence between structures observed from EM data and the formation of mineralised lithium clay pans. This further enhances the likelihood of the pans, where mineralisation tends to increase to depth, having been mineralised through lithium rich brine water-table fluctuation. By comparing water quality of holes drilled outside of the anomalous areas from publicly available data to the levels of electro- conductivity within EM anomalous zones we expect highly concentrated dissolved solids of salts (brines) to be encountered within the anomalous zones.
Our focus is now to drill three stratigraphic holes to verify the geophysical results, to increase our geological understanding of the Bitterwasser basin and to obtain valuable information regarding the sediments associated within the basin. This will be necessary before we embark on a targeted brine-borehole drilling programme. Although not the objective, it is not excluded that stratigraphic drilling could lead to the discovery of a significant brine deposit at Bitterwasser.”
GEOPHYSICAL INTERPRETATION
Interpretation of government Magnetic data purchased from the Ministry of Mines and Energy of Namibia indicates the presence of three major north-south trending faults that are considered responsible for the formation of the Bitterwasser half graben structure. Various en-echelon faults (i.e. faults, or tension fractures, that are oblique to major structural trends) are associated with the large north-south trending fault structures (see Figure 1 right-hand image). The north-east southwest trending fault in the southern portion of the magnetic image is considered to have caused an up-lift of the basement basalt. As a result, the barrier for the creation of the Bitterwasser basin was formed thereby creating a closed basin and trapping water flow from the north and acting like a dam wall (indicated by the red striped polygon on the right-hand image).
Figure 1 – Maps showing the Magnetic Survey data with and without interpretation, the red striped polygon on the southern portion of the area shows the basement high.
Figure 2 – EM survey Results showing three anomalous bodies (represented by pinkish colour)
The interpretation of both the Magnetic and Electro-Magnetic data (as represented in figure 3 below) indicates a well-defined correlation between the anomalies (derived from the Electro-Magnetic data and shown in figure 2) and structural features (derived from the Magnetic data and shown in figure 1). The largest EM anomaly (42km by 9km) is associated with a major north-northwest trending fault structure and the most southern, north-east southwest trending “dam wall” fault. The two smaller anomalies, which are concordant with the Eden Basin (8km by 2.5km) and the Madube Basin (5km by 1.5km) are associated with en echelon faults associated with the two large parallel north-northwest trending fault structures. The formation of the three basins identified so far is thus considered to have been structurally controlled.
This article includes content from Arcadia Minerals, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.
AM7:AU
Quarterly Activities Report – June Quarter 2022
HIGHLIGHTS
- Bitterwasser Lithium Project: Final assay results for remaining 32 of the 64 holes drilled over the Eden Pan on a 500m grid received
- Bitterwasser Lithium Project: Regional investigation into Bitterwasser Lithium-in-clay and Lithium-in-brines minerals system defined extensive tectonic rift-related fault structures in a closed basin (the Kalkrand half-graben), similar to Clayton Valley in Nevada1
- Kum-Kum Nickel Project: Historical core samples obtained during investigation were sampled and returned the first known record of PGE and Au mineralisation in the ultramafic units of the Tantalite Valley Complex. The best results indicated mineralisation of2:
- 0.71% Ni, 0.28% Cu, 0.84 g/t Pd and 0.4 g/t Pt in orthopyroxenite
- 0.58% Ni, 0.30% Cu, 0.69 g/t Pd, 0.31 g/t Pt and 0.26% Au in orthopyroxenite
- Swanson Tantalum Project: Mineral Resource update delivers an estimate for a total indicated and inferred resource of 2.59Mt (an increase of 115%) at an average grade of 486 ppm Ta2O5 (an increase of 17.9%), 73 ppm Nb2O5 and 0.15 % Li2O.3 An Environmental Clearance Certificate and Mining Licence was also issued for the project.
1 Refer to ASX Announcement dated 09 May 2022 titled “Regional study advances work program for district scale Lithium in brines”
2 Refer to ASX Announcement dated 09 May 2022 titled “Kum-kum nickel project mineral systems approach results”
3 Refer to ASX Announcement dated 06 May 2022 titled “JORC Mineral Resource at Swanson Tantalum project doubles in size
SUMMARY OF MINING EXPLORATION FOR THE QUARTER
Bitterwasser Lithium Project
Assay results for the outstanding 32 drill holes from the 64-hole follow-up auger drilling campaign completed on 9 February 20224 over the Eden Pan was received during the quarter. All the drill holes commenced in the mineralised Upper Brown Clay Unit and every hole, except two drill holes where thin clay units were intercepted at the edges of the Eden Pan, were sampled from top to bottom up to a depth of 9.60m. Notably, the entire sequence of the drill holes sampled (i.e. Upper Brown Clay Unit and Middle Green Glay Unit) returned lithium mineralisation5.
The Middle Green Clay Unit, lithologically named the Middle-Unit (MU), comprises the dominant lithological unit from which the maiden Mineral Resource6 was derived. This green clay unit was intersected in 18 of the 32 drill holes from which assay results were received and extended from a depth of 1.4 m below surface to the maximum End-of-Hole (EOH) depth of 9.60m. A total of 43 holes from the 64-hole follow-up auger drilling campaign intersected the Middle Green Clay Unit at similar depths.
Figure1: Stacked cross section of the Eden Pan depicting drill-hole interpretation with reference to the existing Mineral Resource (green layers) and clay units intercepted in the follow-up auger drilling program.
4 Refer to ASX Announcement dated 10 March 2022 titled “Encouraging lithium drilling assay results at Bitterwasser”.
5 Refer to ASX Announcement dated 2 May 2022 titled “Final Lithium Drilling assay results at Bitterwasser”.
6 Refer to ASX Announcement dated 3 November 2021 titled “Arcadia acquires lithium project with JORC Mineral Resources”.
Click here for the full ASX Release
This article includes content from Arcadia Minerals, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.
Kum-Kum Nickel Project Mineral Systems Approach Results
HIGHLIGHTS
- The Department of Earth Sciences at the University of Stellenbosch concluded a Minerals Systems Approach investigation over the Kum-Kum Ni-Cu-PGE Project Licenses
- During the investigation several historical documents containing exploration results over the Kum-Kum Project were discovered, which reported best historical borehole intersections from three boreholes drilled by Rio Tinto Exploration, Tantalite Valley Minerals and Southern Sphere between 1972 and 1976 as follows:
- 16.00 m @ 0.65% Ni, 0.16% Cu
- 6.00 m @ 0.61% Ni, 0.30% Cu
- 2.44 m @ 0.62% Ni, 0.30% Cu
- Historical core samples obtained were sampled and returned the first known record of PGE and Au mineralisation in the ultramafic units of the Tantalite Valley Complex. The best results indicated mineralisation of:
- 0.71% Ni, 0.28% Cu, 0.84 g/t Pd and 0.4 g/t Pt in orthopyroxenite
- 0.58% Ni, 0.30% Cu, 0.69 g/t Pd, 0.31 g/t Pt and 0.26% Au in orthopyroxenite
- The primary magmatic sulphides comprise of coarse-grained pentlandite, pyrrhotite, and chalcopyrite
- Whole rock geochemistry highlights the geochemical similarities between the TVC and the Kum-Kum complexes. The TVC crystallized as a mafic/ultramafic layered intrusion and likely from a primitive mantle-derived parental magma.
Philip le Roux, the CEO of Arcadia stated:
“Historical drilling results reporting high values of Nickel and Copper mineralisation attracted us to the Kum-Kum Project. From the work done by the team from the University of Stellenbosch it is evident that PGE and Au mineralisation is also present and that we are looking at a geological environment that possibly could contain a stratiform Ni-Cu-PGE disseminated sulphide ‘reef’ horizon. The prospect of possibly discovering a polymetallic (Ni, Cu, Au & PGE’s) deposit has increased the allure of the KumKum Project for us, which we will eagerly follow up with further exploration. The results of the study will assist the Company to focus its exploration efforts in order to define drill targets.”
Mineral Systems Approach Results
The Tantalite Valley Complex (TVC) has been subject to a geological study by a team from Arcadia and the University of Stellenbosch involving two field sampling campaigns (8 days; 94 field samples collected) augmented with detailed consideration of historical drill core segments (57 samples), and supporting data from historical records, hyperspectral mapping, and stream sediment sampling.
Collected field- and core- samples were subjected to a suite of analytical protocols including reflected- and transmitted-light optical petrography, whole-rock major and trace element chemistry, precious metal assays, sulphur isotope analyses, scanning electron microscopy with associated spectrometries and in-situ Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) of individual sulphide grains. Together, these results provide novel insights into the known mineralisation and prospectively of the TVC.
The TVC is a ~7 km long by 3.3 km wide and roughly oval-shaped mafic-ultramafic complex representing a fault-bound block inside a dextral Pofadder Shear Zone (PSZ) that cuts across southern Namibia. Existing geochronology places the TVC as a ~1.2 Ga intrusion and roughly coeval with a Kum Kum Klippe mafic complex that is located roughly 40 km south-east and along the strike of the PSZ.
Whole rock geochemistry highlights the geochemical similarities between the TVC and the Kum Kum suite, but with the former uniquely showing much stronger geochemical evidence for overwhelmingly cumulate rocks. This implies that the TVC crystallized as a significant mafic/ultramafic layered intrusion and likely from a primitive mantle-derived parental magma that originated from a metasomatized mantle.
Click here for the full ASX Release
This article includes content from Arcadia Minerals, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.
