Resource Drilling Commenced - Rare Earths Project

In brief · summary, not quotable

Cobra Resources PLC has commenced resource definition drilling at its Wudinna rare earth prospects, Boland and Head, utilizing two Sonic Core drill rigs. This follows successful metallurgy and infield hydrology studies by ANSTO, indicating that the Boland mineralisation can be mined via non-invasive and low-cost in situ recovery (ISR). The company aims to drill out a maiden Mineral Resource Estimate (MRE) of scale, with plans for up to 36 drillholes at Boland and 54 at Head, expecting laboratory results in early April. The project's economic potential is supported by low acid consumption, potential for self-acid generation, and effective cerium suppression, as demonstrated by the production of a high-purity Mixed Rare Earth Carbonate (MREC).

Full announcement

Select text to share a quote on X · sign in to keep highlights & notes in your COBR notes

Having proven outstanding metallurgy, resource definition drilling has now commenced at Boland and Head rare earth prospects

Cobra (LSE: COBR), a South Australian mineral exploration and development company, is pleased to announce resource definition drilling using two Sonic Core drill rigs has commenced across its Wudinna rare earth prospects, Boland and Head.

Infield hydrology studies and bench scale tests completed by the Australian Nuclear Scientific Technology Organisation ("ANSTO") support that the mineralisation at Boland can be mined through non-invasive and low-cost in situ recovery ("ISR"). The Company's next objective is to drill out a maiden Mineral Resource Estimate ("MRE") of scale.

The Boland Project represents a new form of ionic rare earth mineralisation where unique permeable geology enables confined aquifer ISR that bypasses traditional challenges of processing clay ores and mitigates the environmental risks associated with gravity reliant ISR processes.

The project's economic potential is underpinned by low acid consumption with additional cost reduction possible through the promotion of self-acid generation, and the ability to cost effectively supress cerium. The Company has recently demonstrated these benefits by producing a high purity, globally superior Mixed Rare Earth Carbonate ("MREC") through an optimised flowsheet.

The Company is now working to demonstrate scale to support economic analysis through a planned scoping study.

To watch a video of Rupert Verco, Managing Director, discussing the planned programmes visit: https://investors.cobraplc.com/link/rka9zy

Highlights:

Two sonic core drill rigs have commenced drilling at the Boland prospect
Drilling of up to 36 drillholes (approximately 2,000m) planned at the Boland prospect
Drilling of up to 54 drillholes (approximately 2,500m) planned at the Head prospect
Drilling expected to take approximately 4-6 weeks
First laboratory results expected in early April
Drilling is designed to support a maiden MRE for in situ recoverable Heavy Rare Earths ("HREE")

Rupert Verco, Managing Director of Cobra, commented:

"We have optimised the process for high grade and low impurity MREC production and confirmed hydrology parameters that support productive ISR, ultimately demonstrating the viability to recover Boland mineralisation through this method.

In short, Cobra has proven outstanding metallurgy at Boland. It is now time to demonstrate scale to underpin a multigenerational operation. This programme will focus on the two prospects with the highest economic potential, with Boland, given its advanced studies, being the top priority. The Head target has ISR recoverable mineralisation up to 8 metres thick, and initial metallurgical results are favourable too. This target has the potential to add significant scale and economic efficiency due to these broad intersections and is the next priority.

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) has recently completed a study on the mineralisation at Boland. In their testing, Boland was the only project that achieved metallurgical recoveries of 25% with tap water in sequential leach tests. This highlights not only the economic benefits of this style of mineralisation but its delicate nature and the need to use Sonic Core drilling to secure the most representative sample."

Figure 1: Sonic Core drilling in progress at the Boland Project.

Figure 2. A second track mounted rig in action.

Figure 3: Planned drilling collars at the Boland and Head prospects.

Figure 4: Mineralised Pidinga formation from CCSC0021 29-31 meters.

Exploration update: "Exceptional Results - Infield Permeability Study", dated 17 November 2025
Exploration update: "Metallurgical Optimisation Upside", dated 20 October 2025
Exploration update: "Exceptional Metallurgical Results from ISR Column", dated 14 October 2025
Exploration update: "Met Study Supports Even Lower-Cost Recoveries", dated 11 September 2025
Exploration update: "Low-Cost Recoveries from Optimised Testing", dated 11 August 2025
Exploration update: "Rare Earth ISR System beyond Boland", dated 4 August 2025
Exploration update: "Favourable Boland Metallurgical Results", dated 21 July 2025
Exploration update: "Boland Project Update", dated 26 June 2025
Wudinna Project Update: "Boland Aircore Drill Results", dated 25 February 2025
Wudinna Project Update: "2nd Bench Scale ISR Study & £1.7M Placing", dated 26 November 2024
Wudinna Project Update: "ISR Bench Scale Study Completion", dated 4 November 2024

References:

Cobra RNS: Option to Acquire Significant Copper Project, 26 August 2025

Regional map showing Cobra's tenements in South Australia

LinkedIn: https://www.linkedin.com/company/cobraresourcesplc

X: https://twitter.com/Cobra_Resources

Subscribe to our news alert service: https://investors.cobraplc.com/auth/signup

Appendix 1: JORC Code, 2012 Edition - Table 3

Criteria	JORC Code explanation	Commentary
Sampling techniques	· Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. · Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. · Aspects of the determination of mineralisation that are Material to the Public Report. · In cases where 'industry standard' work has been done this would be relatively simple (eg 'reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay'). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information.	Historic · Historic drill programs have been conducted by multiple companies and methods the historically reported results are being reviewed prior to any broader reporting of results. In general lab assay results across differing programs show comparable tenors of grade and distribution.
Drilling techniques	· Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc).	Historic Drilling · Historic drill methods were predominantly aircore and RC driiling with some diamond drilling reported
Drill sample recovery	· Method of recording and assessing core and chip sample recoveries and results assessed. · Measures taken to maximise sample recovery and ensure representative nature of the samples. · Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material.	· Historic recoveries have not been assessed. · Drill methods and geological conditions are not expected to promote significant reduced recovery or sample biasing
Logging	· Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. · Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. · The total length and percentage of the relevant intersections logged.	· Historic logging has been completed with a number of different geological logging codes. These are being translated into a standardized logging format prior to entry into the Cobra Drillhole Database
Sub-sampling techniques and sample preparation	· If core, whether cut or sawn and whether quarter, half or all core taken. · If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. · For all sample types, the nature, quality and appropriateness of the sample preparation technique. · Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples. · Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. · Whether sample sizes are appropriate to the grain size of the material being sampled.	Historic · Historic sampling has not been assessed.
Quality of assay data and laboratory tests	· The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. · For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. · Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established.	Historic · Lab certificates for a large number of drill samples have been retained from historic drilling. These certificates will be used for the import of data into Cobra's drillhole database.
Verification of sampling and assaying	· The verification of significant intersections by either independent or alternative company personnel. · The use of twinned holes. · Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. · Discuss any adjustment to assay data.	Historic · Reported significant intercepts have been reported to the Australian Stock Exchange in the past · Primary assay data and drill logs for reported holes have been reviewed by Cobra staff · Further migration of historic data into the Cobra drillhole database is underway with validation during this process to be undertaken.
Location of data points	· Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. · Specification of the grid system used. · Quality and adequacy of topographic control.	Historic · Historic Drillholes were recorded with a number of different datums. · Validation of the datums used for each program have been conducted and are continuing.The key historic drilling used for planning of the January 2026 drill program have high confidence in the datum used and have been assessed in the field
Data spacing and distribution	· Data spacing for reporting of Exploration Results. · Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. · Whether sample compositing has been applied.	Historic · Historic drilling was variably spaced. The drill spacing was sufficient to define mineralization trends at the Blue Rose Skarn but not to the extent of defining a resource. · Drilling at Desert Rose and Double Delight has not been sufficient to assess the prospects and has been sparse
Orientation of data in relation to geological structure	· Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. · If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material.	· Drillholes have been vertical or south dipping · Deeper historic drilling has been south dipping · Mineralization is interpreted to be steeply dipping with limited success to date in identifying a slight north or south dip. · Deeper planned drilling is expected to help with this interpretation
Audits or reviews	· The results of any audits or reviews of sampling techniques and data.	·
Appendix 2: Section 2 reporting of exploration results
Criteria	JORC Code explanation	Commentary
Mineral tenement and land tenure status	· Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. · The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area.	· Blue Rose is located on EL6009 that is held by Hamelin Gully Pty Ltd. Manna Hill Mining Pty Ltd, a subsidiary of Cobra Resources Plc has a 12-month option to acquire Hamelin Gully. · This drilling forms part of the company's strategy to seek shareholder approval to exercise the option. · A 1% Over Riding Royalty Agreement is registered between Hamelin Gully and Springton Trust A Native Title Agreement is in place between the Wilyakali People and Hamelin Gully Pty Ltd Cultural heritage surveys have been completed over EL6009, clearing proposed drill sites
Geology	· Deposit type, geological setting and style of mineralisation.	Blue Rose · Blue Rose is skarn hosted mineralization on the margins of the Anabama Granite · The skarn is interpreted to be stratabound Neptune Rose · Is interpreted to be hosted within skarn mineralization. · Assessment of the structural vs stratigraphic controls on mineralization will be assessed during drilling Black Baccara · Is interpret to be a sulphide rich halo around a magnetic low core. Assessment of Geological survey spectral from nearby "near miss" diamond holes indicate the metamorphic gradient and spectral responses anticipated from a porphyry system
Further work	· The nature and scale of planned further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling). · Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive.	· RC drill program at Blue Rose, Desert Rose and Double Delight in early January 2026 · Follow up diamond drilling at Desert Rose · Greenfields soil sampling program

Cleaned text: letterheads, contacts and legal notices removed. View the original announcement ↗ · Company filings. Not investment advice.