U.S. Government-funded extension drilling confirms resource growth potential at Jervois' ICO
Highlights:
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U.S. Department of Defense (“DoD”) Defense Production Act (“DPA”) Title III funded extensional drilling at Jervois’ 100%-owned Idaho Cobalt Operations (“ICO”) has returned positive indication of RAM resource growth potential
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Deepest targeted drilling to date at ICO demonstrates strong cobalt-copper-gold mineralisation over mineable widths outside existing reported resource wireframes
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Four extensional drillholes completed; all holes intersected the main mineralised horizon (“MMH”). Analytical results include:
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1.8 metres calculated true width (“CTW”) @ 1.10% cobalt (“Co”), 1.18% copper (“Cu”) and 0.69 grams per metric tonne gold (“g/t Au”) (Hole JU24-093)
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4.8m CTW @ 0.18% Co, 0.34% Cu and 0.10 g/t Au (JU24-095)
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2.1m CTW @ 0.48% Co, 0.60% Cu and 0.86 g/t Au (JU24-096)
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5.5m CTW @ 0.61% Co, 1.35% Cu and 1.51 g/t Au (JU24-097)
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These results are complemented by hangingwall (“HW”) intercepts in JU24-093, JU24-095 and JU24-096, depicting positive continuity of semi-parallel HW mineralisation:
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3.8m CTW @ 0.48% Co, 1.74% Cu and 1.13 g/t Au (JU24-093)
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2.7m CTW @ 0.38% Co, 0.22% Cu and 0.27 g/t Au (JU24-095)
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5.2m CTW @ 1.40% Co, 1.38% Cu and 2.23 g/t Au (JU24-096)
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Prior to drilling, ICO’s mineral resource was already the largest and highest grade confirmed cobalt orebody in the U.S.
31 July 2024 (Australia) – TheNewswire - Jervois Global Limited (“Jervois” or the “Company”) (ASX: JRV) (TSX-V: JRV) (OTC: JRVMF) is pleased to report results from the first four drillholes as part of its United States (“U.S.”) Department of Defense (“DoD”) Defense Production Act (“DPA”) Title III fully refundable extensional drilling program at its Idaho Cobalt Operations’ (“ICO”) RAM deposit in Idaho, U.S.
These drilling results complement those obtained at its 100%-owned Sunshine deposit1,2 under Jervois’ US$15 million DoD DPA Title III funding agreement (“DoD Agreement Funding”).
RAM drill results to date include:
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Hole JU24-093: 1.10% cobalt (Co”), 1.18% copper (“Cu”), 0.69 grams per tonne (“g/t”) gold (“Au”) over a calculated true width (“CTW”) of 1.8 metres (“”) AND hangingwall (HW”) mineralisation of 0.48% Co, 1.74% Cu, 1.13 g/t Au over a CTW of 3.8m;
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Hole JU24-095: 0.18% Co, 0.34% Cu, 0.10 g/t Au, over a CTW of 4.8m AND HW mineralisation of 0.38% Co, 0.22% Cu, 0.27 g/t Au over a CTW of 2.7m AND footwall (FW”) mineralisation of 0.43% Co, 0.99% Cu, 0.62 g/t Au over a CTW of 1.5m;
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Hole JU24-096: 0.48% Co, 0.60% Cu, 0.86 g/t Au over a CTW of 2.1m AND HW mineralisation of 1.40% Co, 1.38% Cu, 2.23 g/t Au over a CTW of 5.2m, including 3.3m CTW at 2.26% Co, 2.06% Cu, 3.60 g/t Au; and
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Hole JU24-097: 0.61% Co, 1.35% Cu, 1.51 g/t Au over a CTW of 5.5m including 3.9m CTW at 0.75% Co, 1.56% Cu, 1.85 g/t Au.
Results from the initial four drillholes of Jervois’ RAM extensional drilling campaign under its DoD Agreement Funding have yielded positive indication of resource extension both along strike and at depth. Drillhole JU24-097 provides especially positive indication of the potential for extension of the RAM deposit, with its significant mineralisation and width representing the deepest intersection of the MMH to date at ICO. Additionally, the development of significant HW intercepts across 2024 extensional drilling provides further strategic opportunity for cobalt resource growth.
Jervois has temporarily paused its underground drilling programme under the U.S. DoD Agreement Funding at ICO while it works with its primary regulator, the U.S. Forest Service, on recommencing underground activities.
Extensional drilling was conducted from a single underground drilling platform positioned within existing underground mine workings at ICO, with collar coordinates found in Table 1 below.
Table 2 provides intercept grades and calculated true widths from the four completed extensional drillholes as part of the DoD Agreement Funding drilling. All drilling results are provided uncapped and in local ICO Mine Grid Coordinates.
Table 1: RAM DoD Agreement Funding Extensional Drillhole Collars
Coordinates* |
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Hole ID |
Easting (m) |
Northing (m) |
Elevation (m) |
Azimuth (deg.) |
Dip (deg.) |
EOH Depth (m) |
JU24-093 |
610 |
6373 |
2126 |
221 |
-59 |
244 |
JU24-095 |
611 |
6373 |
2126 |
207 |
-87 |
327 |
JU24-096 |
614 |
6373 |
2126 |
135 |
-75 |
428 |
JU24-097 |
614 |
6376 |
2126 |
60 |
-65 |
429 |
* Coordinates provided in Mine Grid of RAM Deposit.
Table 2: RAM DoD Agreement Funding Extensional Drilling Results
Hole ID |
From (m) |
To (m) |
Zone |
True Width* (m) |
Co Grade (%) |
Cu Grade (%) |
Au Grade (g/t) |
JU24-093 |
155.3 |
159.3 |
HW |
3.8 |
0.48 |
1.74 |
1.131 |
JU24-093 |
174.4 |
176.5 |
MMH |
1.8 |
1.10 |
1.18 |
0.686 |
JU24-093 |
200.6 |
203.7 |
FW |
2.6 |
0.15 |
1.57 |
0.309 |
JU24-095 |
194.7 |
198.1 |
HW |
2.7 |
0.38 |
0.22 |
0.274 |
JU24-095 |
207.1 |
212.8 |
MMH |
4.8 |
0.18 |
0.34 |
0.103 |
JU24-095 |
264.0 |
266.3 |
FW |
1.5 |
0.43 |
0.99 |
0.617 |
JU24-096 |
221.9 |
229.2 |
HW |
5.2 |
1.40 |
1.38 |
2.229 |
JU24-096 |
241.4 |
244.3 |
MMH |
2.1 |
0.48 |
0.60 |
0.857 |
JU24-097 |
393.6 |
405.0 |
MMH |
5.5 |
0.61 |
1.35 |
1.509 |
* Calculated true widths determined for the composited intercept mid-point, perpendicular to the down-dip
projection of the RAM deposit
Note: All grades are reported uncut for both MMH and HW/FW zones
Jervois has successfully completed 2,500m of targeted resource expansion drilling across both its 100%-owned RAM and Sunshine deposits under the DoD Agreement Funding, as well as more than 350m of underground mine development in support of DoD Agreement Funding extensional drilling.
Underground drilling of the RAM deposit during the ongoing programme has highlighted appreciable grades, widths and mineralisation continuity. The Company’s deepest intercept to date indicates strong upside potential of further resource extension at depth, which Jervois anticipates will be tested with future drilling.
Figure 1 and 2 below show an updated RAM long section and RAM plan view section, respectively, including completed 2024 DoD Agreement Funding drilling and 2023 RAM MRE outline in green.
Figure 1: RAM Long Section including 2024 DoD Agreement Funding Extensional Drilling
Figure 2: RAM Plan View including 2024 DoD Agreement Funding Extensional Drilling
Recent drilling results have demonstrated down-dip grade continuity along an interpreted orientation favourable to continued exploration by Jervois within its contiguous claim boundaries. This updated interpretation of the MMH in the southern extents of the RAM provides additional pathways to resource growth, previously believed to be limited to deep exploratory drilling, with additional moderate-depth extensional drilling at ICO. Greater continuity of HW mineralisation is also observed along this mineralised orientation based upon the 2024 drilling programme, indicating further resource growth opportunity.
Jervois’ 2024 extensional drilling has successfully displayed continuity of prospective mineralisation across all completed holes with step-out intercepts ranging between 100m to 175m from the nearest neighbouring pre-2024 intercept laterally and consolidates mineralisation confidence across greater than 450m down-dip along and beyond existing 2023 MRE margins. Figure 3 shows 2024 drilling in comparison to expansion drillhole JU22-0653, highlighting continuity in both MMH and HW zones present within southern reaches of the RAM deposit.
Figure 3: Cross Section depicting 2024 DoD Agreement Funding Extensional Drilling
Quality Assurance
All drill core samples are sent to ALS Global Laboratories (Geochemistry Division), an independent and fully accredited laboratory (ISO 9001:2008), in Vancouver, Canada, for analysis for gold by Fire Assay and multi-element Induction Coupled Plasma Spectroscopy. Jervois employs a regimented Quality Assurance, Quality Control (“QA/QC”) program where at least 10% duplicates, blanks and certified reference material are inserted into each sample shipment.
On behalf of Jervois Global Limited
Bryce Crocker, Chief Executive Officer
For further information, please contact:
Investors and analysts: Alicia Brown Group Manager – External Affairs Jervois Global alicia.brown@jervoisglobal.com |
Media: Nathan Ryan NWR Communications nathan.ryan@nwrcommunications.com.au Mob: +61 420 582 887 |
Competent Person’s Statement
The information in this release that relates to Mineral Exploration is based on information compiled by Andrew Turner, P.Geol. who is a consultant for the company and a member of The Association of Professional Engineers and Geoscientists of Alberta. Andrew Turner has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking 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’. Andrew Turner consents to the inclusion in the release of the matters based on the information in the form and context in which it appears.
Qualified Person’s Statement
The technical content of this news release has been reviewed and approved by Andrew Turner, P.Geol., a consultant for the Company and a Qualified Person as defined by National Instrument 43-101.
Forward-Looking Statements
This news release may contain certain “Forward-Looking Statements” within the meaning of the United States Private Securities Litigation Reform Act of 1995 and applicable Canadian securities laws. When used in this news release, the words “anticipate”, “believe”, “estimate”, “expect”, “target, “plan”, “forecast”, “may”, “schedule”, “expected” and other similar words or expressions identify forward-looking statements or information. These forward-looking statements or information may relate to the timing of drilling operations at ICO, the outcome of the drilling program, future updated mineral resource and certain other factors or information. Such statements represent Jervois’ current views with respect to future events and are necessarily based upon a number of assumptions and estimates that, while considered reasonable by Jervois, are inherently subject to significant business, economic, competitive, political and social risks, contingencies and uncertainties. Many factors, both known and unknown, could cause results, performance or achievements to be materially different from the results, performance or achievements that are or may be expressed or implied by such forward-looking statements. Jervois does not intend, and does not assume any obligation, to update these forward-looking statements or information to reflect changes in assumptions or changes in circumstances or any other events affections such statements and information other than as required by applicable laws, rules and regulations.
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
Appendix 1:
JORC Code, 2012 Edition – Table 1
Section 1 Sampling Techniques and Data
Criteria |
JORC Code explanation |
Commentary |
Sampling techniques |
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All drill core was sampled contingent on geology and core recovery: Core was collected directly from the core barrel into core boxes, and drill core was cut in half by diamond saw, with one half of the core collected for laboratory analysis and the other half retained as reference core in the tray. Core trays were clearly labelled with the hole number, tray number and depth intervals marked. A “cut-line” was drawn by the logging geologists along the length of the drill core as a guide for the core sawing. The half-core was sampled, ensuring that the same side is consistently sampled, and placed into sample bags labelled with the assigned sample number. Downhole measurements are recorded using a Reflex OMNI Gyro at 30 metre intervals down each hole and at 1.5 metre intervals continuously at the end of every hole. Field sampling followed Jervois protocols including industry standard quality control procedures. Samples were sent to: ALS Geochemistry-Vancouver, an independent and fully accredited laboratory in Vancouver, Canada (“ALS”) for analysis for gold by 30g Fire Assays with wet chemical finish (ICP) and by multi-element Induction Coupled Plasma Spectroscopy (“ICP”). Jervois also has a regimented Quality Assurance, Quality Control (“QA/QC”) program where at least 10% standards and blanks are inserted into each sample shipment.
Diamond Core: core samples are “representative” (and not “selective”) in that each sample comprised half (cut) core that was collected along the entire length of each sample interval. Handheld XRF instruments were used to spot check drill core for mineralisation, however those results were not relied on. All sample results reported on are from ALS, an independent laboratory. All of the drilling was diamond drill core (HQ/NQ). Typically, drill core was sampled on nominal 3 foot (~1m) half core samples for HQ/NQ. All sample analyses were completed at ALS . ALS operates independent laboratories globally, which are ISO accredited. Samples are received at the laboratory: Bar codes are scanned and logged; samples are weighed and dried; samples are crushed to 70% less than 2mm, the crushing product is riffle split to collect a 250g split, which is pulverised to better than 85% passing 75 microns; aliquots from the pulverised split (the sample “pulp”) are analysed for 34 elements using ICP analysis and for gold by 30 gram Fire Assay with ICP-AES finish. Any samples with initial “over-limit” results for specific metals, including gold, copper, cobalt and arsenic are re-analysed accordingly to achieve complete results. |
Drilling techniques |
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Underground drilling comprised HQ and NQ sized core, with reduction of hole size where appropriate. Holes were generally angled from -55 to -90 degrees at varying azimuths. |
Drill sample recovery |
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All holes are logged for basic geotechnical characteristics including measurements and calculations for core recovery and RQD values. Core recovery is recorded as a percentage equivalent to the length of core recovered, as a percentage of the drill run (interval length). Excellent recoveries were obtained from the diamond drilling. There is no bias noted between sample recovery and grade. Excellent recoveries were obtained from Diamond drilling other than in faulted zones which were not sampled. |
Logging |
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Diamond drilling: Drill core is photographed and logged prior to sampling; Core has been geologically and geotechnically logged to a level of detail appropriate to support mineral resource estimation and mining studies. Logging has been conducted both qualitatively and quantitatively; full description of lithologies, alteration and comments are noted, as well as percentage estimates on veining and sulphides. The total length of all holes drilled to date in 2024 was 1,428m. All depths of relevance to this release are listed in the table in the body of the text. All drill holes are logged in their entirety. |
Sub-sampling techniques and sample preparation |
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All core was half-cut lengthwise using a diamond saw. The HQ/NQ core half-core was sampled. Samples are received at the laboratory: sample ID bar codes are scanned and logged; samples are weighed and dried; samples are crushed to 70% less than 2mm, the crushing product is riffle split to collect a 250g split, which is pulverised to better than 85% passing 75 microns; aliquots from the pulverised split (the sample “pulp”) are analysed for 34 elements using ICP analysis and for gold by 30 gram Fire Assay with ICP-AES finish. Any samples with initial “over-limit” results for specific metals, including gold, copper, cobalt and arsenic are re-analysed accordingly to achieve complete results. For core sampling the same side is consistently sampled, half-core is retained in the tray for HQ/NQ. The assay sub- sample is placed into sample bags labelled with the assigned sample number. One in 20 samples is duplicated where the core is quartered and a quarter cut sample is analysed as a duplicate. The remaining quarter samples is retained in the tray. Sample sizes of 2-3 kg are appropriate for the grain size of material. The sample preparation technique and sample sizes are considered appropriate to the material being sampled. |
Quality of assay data and laboratory tests |
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The ICP-AES and Fire Assay (30 gram) analytical techniques are considered total and are high quality and appropriate for the mineralisation being tested. Jervois has a regimented Quality Control protocol which has consisted of systematic submission of blanks, standards and duplicates in addition to those conducted at the laboratory. Precision levels for all blanks, standards and duplicate samples fell within acceptable ranges. |
Verification of sampling and assaying |
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Significant intersections are alternatively verified by the CP and QP of the company. No holes have been twinned in this drill programme. Data is collected using a PostGRE SQL database custom-built for Idaho Cobalt Operations and incorporates historic MS Excel templated data. The database software includes data validation algorithms. The database software also allows for the direct importation of digital data files from the laboratory. Data is backed up on the cloud hosted server on and off site. All assay/analytical data returning “below detection limit” results have been entered in the project database as one half of the detection limit value. Samples received damaged at the laboratory, or with insufficient sample weight for analysis had the interval or location left blank. |
Location of data points |
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All surface drilling collars were surveyed by licensed surveyors and by trained geologists in the underground. Down-hole surveys were routinely carried out on all holes using a Reflex OMNI Gyro at 30 metre intervals down each hole and at 1.5 metre intervals continuously at the end of every hole. Holes were setup on collar using a Reflex TN14 Gyro. All datum is collected and recorded in a localised ICO Mine Grid. The 3D location of the individual samples is considered to be adequately established, consistent with accepted industry standards. |
Data spacing and distribution |
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To date, due to the exploratory nature of the drilling, the spacing is wide. Assay results for four holes have been received. The intervals released are proximal to the existing RAM deposit MRE and are interpreted as representing an extension of the RAM deposit. As a result, this data, will be used in a planned mineral resource update upon completion of the ongoing extensional drilling programme. The reported drillhole data comprises length-weight averaged core interval grade values. Data compositing is completed during Mineral Resource Estimation, but has not been applied to the data reported in this release. |
Orientation of data in relation to geological structure |
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Drilling sections are orientated perpendicular to the strike of the host rocks. Drill holes were inclined between -55° and -90° to optimise intercepts of mineralisation with respect to thickness and distribution. Drilling with angled holes in most instances provides a representative sample across the stratigraphy. |
Sample security |
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All individual samples are placed in plastic sample bags sealed with a cable tie. Then groups of samples are bagged in poly-woven sacks also sealed with a cable tie. The samples are sent by courier to the lab and tracked. To date, no sample shipments have had reported problems and/or a breach in security. |
Audits or reviews |
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Jervois protocols consist of a regimented internal QA/QC which match or exceed global industry standards. APEX Geoscience Ltd. has been retained as independent geological consultants and have reviewed and approved the ICO sampling protocols and procedures and will be conducting a thorough review of the drill data, including the QA/QC data, prior to the initiation of resource update. |
Section 2 Reporting of Exploration Results
Criteria |
JORC Code explanation |
Commentary |
Mineral tenement and land tenure status |
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ICO consists of 358 unpatented mineral claims totalling 7,390 acres. The claims are 100% owned by Jervois subsidiary Jervois Mining USA Ltd. and are in good standing. Unpatented Mineral Claims: Ownership of unpatented mining claims in the U.S. is in the name of the holder, with ownership of the minerals belonging to the United States of America, under the administration of the U.S. Bureau of Land Management. Under the Mining Law of 1872, which governs the location of unpatented mining claims on federal lands, the locator has the right to explore, develop and mine minerals on unpatented mining claims without payments of production royalties to the federal government. Annual claim maintenance and filing fees paid before September 1st each year are the only federal encumbrances to unpatented mining claims. Exploration plans are permitted and administered by the Unites States Forestry Service. The United States Department of Agriculture Salmon Challis National Forest (the Forest Service) issued a revised Record of Decision (the “ROD”) for the ICO in January 2009. The ROD described the decision to approve a Mine Plan of Operations (“MPO”) for mining, milling and concentrating mineralised material from the ICO. The ROD was subsequently affirmed by the Forest Service in April 2009. The Plan of Operations at the ICO mine and mill remained unchanged and the ROD remains in place. In December 2009, the Forest Service approved the MPO allowing for the commencement of ICO construction. There are no known encumbrances. |
Exploration done by other parties |
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The ICO came under Jervois management following the merger with eCobalt in 2019. Prior to this merger, the area has a long history of copper and cobalt exploration and mining. Copper mineralisation in the Blackbird Creek area was discovered in 1892, and the area was soon explored as both a copper and gold prospect. The area was first mined by Union Carbide at the Haynes-Stellite Mine located south of the present ICO claim block, during World War I. Union Carbide mined approximately 4,000 tons of cobalt-bearing ore before ceasing operations. From 1938 to 1941, the Uncle Sam Mining and Milling Company operated a mine at the south end of the present Blackbird mine and reportedly mined about 3,600 tons of ore. Calera Mining Company, a division of Howe Sound Company, developed and mined the Blackbird deposit between 1943 and 1959 under a contract to supply cobalt to the U.S. government. Calera stopped mining when the government contract was terminated in 1960. Machinery Center Inc. mined from the district between 1963 and 1966, when Idaho Mining Company (owned by Hanna Mining Company) purchased the property. Noranda optioned the property from Hanna in 1977 and carried out extensive exploration, mine rehabilitation and metallurgical testing. In 1979 Noranda and Hanna formed the Blackbird Mining Company (BMC) to develop the property. BMC completed an internal feasibility study of their property at the time, including material from the Sunshine deposit in 1982. BMC allowed perimeter claims to lapse in 1994, and eCobalt restaked much of that ground. From 1995 to the present, eCobalt completed surface geochemical sampling and drilled 158 diamond drill holes on the ICO ground. |
Geology |
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Deposit Types: Whilst the deposits in the Idaho Cobalt Belt have been studied over many years the deposit types are still a subject of debate. Prior to 2005 the overriding opinion was that the deposits are sedimentary exhalative and are referred to as the Blackbird Sediment Hosted Cu-Co. And have been described as stratabound iron-, cobalt-, copper-, and arsenic-rich sulphide mineral accumulations in nearly carbonate-free argillite/siltite couplets and quartzites Post 2005 the discovery of high concentrations of rare earth elements (“REE”) lead to the postulation that the deposits are not volcanogenic massive sulphide or sedimentary exhalative deposits but instead are iron oxide-copper-gold (“IOCG”) deposits Geological Setting: The ICO is situated in the Idaho Cobalt Belt, a 50- to 55-kilometre long metallogenic district characterised by stratiform/tabular copper-cobalt deposits. The deposits are hosted by a thick, dominantly clastic sequence of Middle Proterozoic age sandwiched between late Proterozoic quartz monzonitic intrusions. The clastic sediments were deposited in a large fault-bounded basin, probably as large submarine fan complexes and/or deltaic aprons that were frequently “drowned” by continuing subsidence within the basin. All significant copper-cobalt deposits and occurrences are found in the Proterozoic Apple Creek Formation, which constitutes the base of this sequence. This formation was originally correlated with Pritchard Formation metasediments of the Belt supergroup to the north, its age being constrained by dates of 1.37 Ga for adamellites intruding the sequence and 1.7 Ga from mafic dykes and sills emplaced along the basin margin faults. The structure of the Apple Creek Formation is dominated by the regional rift structure. Cobalt-copper-gold mineralization occurs along a northwest-southeast trending structure parallel to and west of the central axis of the rift. There is a series of northerly trending faults that are considered to represent initial growth faults, reactivated by Laramide and younger events. The district has also been affected by north-easterly structures of the Trans-Challis Fault Zone. The ICO is hosted in Proterozoic age meta-sediments found on the east side of the central Idaho Batholith comprising granitic-to-granodioritic rocks. The Idaho Cobalt Belt represents a distinct district dominated by stratabound cobalt + copper ± gold mineralisation, with a remobilised constituent. The district is underlain by strata of the middle Proterozoic-age Apple Creek Formation, which is an upward-thickening, upward-coarsening clastic sequence at least 14,900 metre thick that represents a major basin-filling episode and was formerly considered part of the Yellow Jacket Formation. The Apple Creek can be divided into three units. The lower unit of the Apple Creek Formation is over 4,500 metre thick and consists mainly of argillite and siltite, with lesser occurrences of fine-grained quartzite and carbonates. Graded bedding and planar to wavy laminae are common in the lower unit, which is locally metamorphosed to phyllite. The middle unit of the Apple Creek Formation is up to 1,100 metres thick and comprises several upward-coarsening sequences of argillite, siltite, and quartzite, with distinctive biotite-rich interbeds that generally have a direct correlation to mineralisation. The middle unit hosts the majority of the known cobalt, copper and gold occurrences in the Idaho Cobalt Belt. The upper unit exceeds 3,000 metres in thickness and is predominantly composed of thin- to thick bedded, very fine- to fine-grained quartzite. Mafic tuffs within the Apple Creek Formation are the oldest igneous rocks exposed in the Sunshine-Blackpine district. They are accompanied by felsic tuffs and carbonatitic tuffs. Some mafic dikes and sills intrude the Apple Creek Formation and may be comagmatic with the mafic tuff beds. Several small lamproitic diatremes may also be coeval with mafic volcanism. The Apple Creek Formation has undergone varying degrees of regional metamorphism, ranging from greenschist facies in the southern part of the district to amphibolite grade facies in the northern part of the district. Several types of mafic dikes and sills, ranging from 1m to 30m thick, intrude the Apple Creek Formation and are interpreted as feeders to the exhalative mafic tuffs, which are most abundant in areas of intrusive activity Style of Mineralisation: Mineralisation at the ICO is characterised as syngenetic, stratiform/tabular exhalative deposits within, or closely associated with, the mafic sequences of the Apple Creek Formation. This mineralisation is dominantly bedding concordant and the deposits range from nearly massive to disseminated. Some crosscutting mineralisation is present that may be in feeder zones to the stratiform mineralisation or may be due to remobilisation locally into fracture quartz veins and/or crosscutting structures. Dominant minerals include cobaltite (CoAsS) and chalcopyrite (CuFeS2), with lesser, variable occurrences of gold. Other minerals present in small quantities are pyrite (FeS2), pyrrhotite (FeS), arsenopyrite (FeAsS), linnaeite ((Co Ni)3S4), loellingite (FeAs2), safflorite (CoFeAs2), enargite (Cu3AsS4) and marcasite (FeS2). Recently, rare-earth minerals have been identified in samples from the deposit as monazite, xenotime and allanite. At this time, these minerals have not been considered for potential recovery as by-products of the Co-(Cu-Au). The RAM is the largest and best-known deposit in the ICO area. It consists of a Hanging-wall Zone with 3 primary and 4 minor horizons, a Main Zone comprising 3 horizons, and a Footwall Zone with 3 horizons. These sub-parallel horizons generally strike N15oW and dip 50o – 60o to the northeast. Most of the significant Co mineralisation is associated with exhalative lithologies i.e. biotitic tuffaceous exhalate (BTE), siliceous tuffaceous exhalate (STE), and quartzite with impregnations of biotitic tuffaceous exhalate (QTZ/BTE) or siliceous tuffaceous exhalate (QTZ/STE). |
Drill hole Information |
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All drillhole information pertinent to this release is contained within the tables in the body of the text. |
Data aggregation methods |
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In previous reports weighted averaging has been used in reported composite intervals and individual results are also listed, no grade truncations etc. has been used. Aggregate intercepts are reported using a grade metre calculation. For example: ((assay x meter interval sampled) + (assay x meter interval sampled) + (assay x meter interval sampled) / divided by total number of meters in the interval). Individual sample intercepts are also shown. Calculated true widths determined for the composited intercept mid-point, perpendicular to the down-dip projection of the RAM deposit. No metal equivalent values have been reported. |
Relationship between mineralisation widths and intercept lengths |
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Downhole lengths are reported. Calculated true widths are reported based on down-dip projections of the RAM deposit model. |
Diagrams |
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Refer to figures and tables in the body of the text. |
Balanced reporting |
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Calculated true widths determined for the composited intercept mid-point, perpendicular to the down-dip projection of the RAM deposit. |
Other substantive exploration data |
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There is no other substantive exploration data. |
Further work |
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Jervois plans to continue to undertake extensional drilling to support an updated MRE as funding allows. |
1 See ASX announcement “Jervois completes U.S. Department of Defense reimbursed drilling at ICO’s Sunshine deposit” dated 30 January 2024
2 See ASX announcement “Jervois completes maiden JORC Resource for Sunshine at ICO, USA” dated 2 April 2024
In accordance with ASX listing rule 5.23.2, Jervois confirms it is not aware of any new information or data that materially affects the information included in the relevant market announcements referred to above and that the assumptions contained therein continue to apply and have not materially changed.
3 See ASX announcement “Expansion drilling consolidates RAM deposit extension at Jervois’ ICO” dated 20 February 2023.
In accordance with ASX listing rule 5.23.2, Jervois confirms it is not aware of any new information or data that materially affects the information included in the relevant market announcement referred to above and that the assumptions contained therein continue to apply and have not materially changed.