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Share Name | Share Symbol | Market | Type | Share ISIN | Share Description |
---|---|---|---|---|---|
Cobra Resources Plc | LSE:COBR | London | Ordinary Share | GB00BGJW5255 | ORD 1P |
Price Change | % Change | Share Price | Bid Price | Offer Price | High Price | Low Price | Open Price | Shares Traded | Last Trade | |
---|---|---|---|---|---|---|---|---|---|---|
0.00 | 0.00% | 1.025 | 0.95 | 1.10 | 1.025 | 1.025 | 1.025 | 89,951 | 07:32:49 |
Industry Sector | Turnover | Profit | EPS - Basic | PE Ratio | Market Cap |
---|---|---|---|---|---|
Miscellaneous Metal Ores,nec | 0 | -509k | -0.0009 | -11.33 | 6.04M |
TIDMCOBR
RNS Number : 1048Y
Cobra Resources PLC
07 May 2019
THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF EU REGULATION 596/2014. UPON THE PUBLICATION OF THIS ANNOUNCEMENT VIA A REGULATORY NEWS SERVICE, THIS INSIDE INFORMATION IS NOW CONSIDERED TO BE IN THE PUBLIC DOMAIN.
NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION, IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY IN OR INTO THE UNITED STATES, AUSTRALIA, CANADA, JAPAN, THE REPUBLIC OF SOUTH AFRICA OR ANY OTHER JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OF SUCH JURISDICTION.
7 May 2019
Cobra Resources plc
("Cobra" or the "Company")
Wudinna Gold Project Resource Update
Cobra (LSE:COBR), a company formed to explore, develop and mine precious and base metal projects, today announces that it has received an updated Mineral Resource estimate for the Wudinna Gold Project, located in the Eyre Peninsula of South Australia approximately 25 km north of the township of Wudinna (the "Wudinna Gold Project").
The Wudinna Gold Project is 100% owned by Andromeda Metals Limited ("Andromeda"), a company listed on the Australian Securities Exchange. On 31 October 2017, Andromeda entered into a binding agreement with Lady Alice Mines Pty Ltd ("Lady Alice Mines"), pursuant to which Lady Alice Mines can earn an up-to 75% interest in the Wudinna Gold Project (the "Wudinna Agreement"). On 6 March 2019, the Company entered into an agreement to acquire the entire issued share capital of Lady Alice Mines and 100% of the units in the Lady Alice Trust (the "Lady Alice Acquisition"). Further details of the Wudinna Agreement and the Lady Alice Acquisition can be found in the Company's announcement entitled "Proposed Acquisition of Lady Alice Mines" released via regulatory news service on 7 March 2019 (the "Acquisition Announcement").
Defined terms used but not defined herein shall have the same meanings given to such terms in the Acquisition Announcement.
Following the geological reinterpretation of the Barns, White Tank and Baggy Green deposits by Lady Alice Mines in 2018, Cobra instructed Optiro Pty Ltd ("Optiro"), a well-renowned mining services company based in Perth, Western Australia, to re-estimate the gold resources for the Wudinna Gold Project in accordance with the Joint Ore Reserves Committee 2012 Guidelines.
Key Highlights:
-- The updated Mineral Resource has increased to 4.43 million tonnes at 1.5 g/t gold for 211,000 ounces of gold. The previous resource estimate was 3.85 million tonnes at 1.6 g/t gold for 200,300 ounces.
-- This update represents an increase of 5% in contained gold and 15% in resource tonnes.
-- This resource includes 4.02 million tonnes at 1.5 g/t gold for 193,000 ounces of Inferred resource and 0.41 million tonnes at 1.4g/t gold for 18,000 ounces of Indicated resource.
-- This represents an increase of 0.59 million tonnes or 10,700 ounces of gold when compared to the previous Mineral Resources announced by Andromeda on the 23(rd) January 2017 (refer: http://www.andromet.com.au/images/uploads/reports/20170123_BG_WT_Resource_FINAL.pdf).
-- The Barns, White Tank and Baggy Green deposits are located within 6 km of each other and are shallow and potentially open-pitable.
-- Each of the deposits remain open and step-out drilling can potentially add further resources.
Craig Moulton, Managing Director of Cobra commented:
"I am delighted with the updated resource estimate for this key project in Cobra's portfolio. The increase in the JORC Mineral Resource based on this new interpretation, and without new drilling data, confirms our belief that there is significant value to be unlocked from this exciting project."
Detail:
The Mineral Resource estimate, as at March 2019, for the Barns, White Tank and Baggy Green deposits is shown below in Table 1.1. This has been classified and reported in accordance with the guidelines of the Australasian Code for Reporting of Identified Mineral Resources and Ore Reserves, 2012 (the "JORC Code"). The Mineral Resources have been reported above a 0.5 g/t gold cut-off grade to reflect current commodity prices and extraction by open pit mining.
Table 1.1 Classification Tonnes Grade (g/t Gold ounces Mineral (x1,000) gold) Resource estimates, using alternative interpretation and reported above a cut-off grade of 0.5 g/t gold:Deposit Barns Indicated 410 1.4 18,000 Inferred 1,710 1.5 86,000 ------------------------------------- ---------- ----------- ------------ Total 2,210 1.5 104,000 ------------------------------------- ---------- ----------- ------------ White Tank Inferred 280 1.4 13,000 ---------------- ---------- ----------- ------------ Baggy Green Inferred 2,030 1.4 94,000 ---------------- ---------- ----------- ------------ Total 4,430 1.5 211,000 ---------- ----------- ------------
Gold mineralisation at the Wudinna Gold Project is associated with a large hydrothermal alteration halo within granodiorite. At Baggy Green, the host rocks are visibly altered and sheared in and around the mineralised zone. Mineral Resources were previously estimated by Mining Plus Pty Ltd ("Mining Plus") for Andromeda in 2016 for the Barns deposit and in 2017 for the White Tank and Baggy Green deposits.
In 2018, Lady Alice Mines requested Optiro to investigate an alternative orientation to the interpreted mineralisation at Barns, White Tank and Baggy Green aligned with the strong regional northwest/southeast orientation observed in:
-- calcrete gold geochemical data; -- regional gravity and magnetic data; and -- structural interpretation of drill core data.
Variography indicated that the maximum continuity for the mineralisation at Barns is orientated along 305deg, which is consistent with the regional orientation observed by Lady Alice Mines. Lady Alice Mines requested Optiro to re-model the mineralisation at Barns, White Tank and Baggy Green using this as the dominant orientation for the mineralisation and to develop alternative conceptual resource models.
In April 2019, Cobra requested Optiro to re-estimate the Barns, White Tank and Baggy Green resources incorporating this alternative interpretation and new variography.
A nominal cut-off grade of 0.3 g/t gold was used for interpretation of the mineralisation at Barns, White Tank and Baggy Green.
Interpreted mineralisation at Barns extends over and area of 400 mN by 250 mE and is up to 200m deep. Two lodes of flat-lying supergene mineralisation and 12 lodes of shallow dipping, fresh mineralisation have been interpreted. At White Tank, the interpreted mineralisation extends for 250 mN by 150 mE and is up to 120m deep. One lode of flat-lying mineralisation and two shallow dipping lodes of mineralisation within fresh material have been interpreted.
The Baggy Green resource has two areas of mineralisation: within the south the interpreted mineralisation extends over an area of 200 mN by 400 mE and in the north it extends over an area of 150 mN by 300 mE. One lode of flat-lying supergene mineralisation and 13 shallow dipping lodes of mineralisation have been interpreted within the fresh material to a depth of 200m.
The resource models for the Barns and White Tank deposits were constructed using a parent block size of 10 mE by 10 mN on 4m benches; the parent blocks were allowed to sub-cell down to 2 mE by 2 mN by 0.5 mRL to more accurately represent the geometry and volumes of the weathering horizons and mineralisation domains. For Baggy Green, a parent block size of 20 mE by 20 mN by 5 m was used and the parent blocks were allowed to sub-cell down to 4 mE by 4 mE by 1 m RL.
Gold block grades were estimated using ordinary kriging techniques, with search ellipses oriented within the plane of the mineralisation. Hard boundary conditions were applied for grade estimation into each of the mineralised domains (i.e. grade estimation for each domain used only the data that is contained within that domain).
A total of 255 bulk density determinations have been undertaken at Barns on either historical or recent diamond drillholes and 185 bulk density determinations have been undertaken at Baggy Green on recent diamond drillholes. Average values were calculated from the complete dataset by Mining Plus using a combination of weathering and mineralisation. Density values assigned to the mineralised domains in the resource models range from 2.29 t/m(3) to 2.73 t/m(3) .
The mineralisation at Barns, White Tank and Baggy Green has been classified as Indicated and Inferred in accordance with the guidelines of the JORC Code. The Mineral Resources have been classified on the basis of confidence in geological and grade continuity and taking into account data quality (including sampling methods), data density and confidence in the block grade estimation, using the modelled grade continuity and conditional bias measures (slope of the regression) as criteria.
Indicated Mineral Resources have been defined at Barns within the supergene mineralisation in areas where drill spacing is generally 20 mE by 50 mN or less. An Indicated classification was applied to four of the fresh lodes where the drill spacing is generally 20 mE by 50 mN or less and the resources are above 40 mRL. Inferred Mineral Resources have been defined in areas where an extension of mineralisation is supported by the drilling. The total Mineral Resources at White Tank and Baggy Green have been classified as Inferred.
The likelihood of eventual economic extraction was considered in terms of possible open pit mining and results from metallurgical testwork. Metallurgical testwork from material at Barns and Baggy Green indicated gold recoveries ranging from 94.3% to 99.3% and averaging 97.7% across all samples from a combination of conventional gravity and cyanide leaching.
Competent Person Statement - Resource Estimation:
The information in this release that relates to the Estimation and Reporting of Mineral Resources has been compiled by Mrs Christine Standing BSc Hons (Geology), MSc (Min Econs), MAusIMM, MAIG. Mrs Standing is a full-time employee of Optiro and has acted as an independent consultant on the Mineral Resource Estimates for the Barns, Baggy Green and White Tank Deposits. Mrs Standing is a Member of the Australian Institute of Geoscientists and the Australian Institute of Mining and Metallurgy and has sufficient experience with the style of mineralisation, deposit type under consideration and to the activities undertaken to qualify as a Competent Person as defined in the 2012 Edition of the JORC Code. Mrs Standing consents to the inclusion in this report of the contained technical information relating the Mineral Resource estimations in the form and context in which it appears. The detailed Mineral Resources estimation parameters per Table 1 of the JORC Code are set out in Appendix One.
Cautionary Statement
Readers should use caution when reviewing the exploration and historical production results presented and ensure that the Modifying Factors described in the 2012 edition of the JORC Code are considered before making an investment decision.
Additional details on this resource update can be found on Cobra's web site: www.cobraresourcesplc.com
The person who arranged for the release of this announcement on behalf of the Company was Craig Moulton, Managing Director of the Company.
End
Enquiries:
Cobra Resources plc Rolf Gerritsen +44 (0)20 7129 1471 Nick Emerson SI Capital Limited (Broker) Sam Lomanto +44 (0)14 8341 3500 ------------------ ----------------------
Appendix One: JORC Code Table 1 Criteria
The table below summaries the assessment and reporting criteria used for the Barns, White Tank and Baggy Green Mineral Resource estimates and reflects the guidelines in Table 1 of The Australasian Code for the Reporting of Exploration Results, Mineral Resources and Ore Reserves (the JORC Code, 2012). Data included in Sections 1 and 2 has been extracted from Adelaide Resources Limited, 2016 and Andromeda Metals Limited, 2017.
Section 1 Sampling Techniques and Data
Criteria JORC Code explanation Commentary Sampling techniques * Nature and quality of sampling. * Aircore (AC), rotary air-blast (RAB), RC (reverse circulation), rotary hammer (RH) and diamond drilling has been used to obtain 6 m composite and 1 m samples * Include reference to measures taken to ensure sample which have been pulverised to produce sub samples for representivity and the appropriate calibration of any laboratory assay (nominal 50 g or 30 g charge for measurement tools or systems used. gold fire assay with AAS finish). * Data from AC and RAB holes have not been used for resource estimation. * Some samples have also been assayed for a suite of other elements using multi-acid digest of small weight charges finished with ICP-OES and ICP-MS). * Some screen fire assays have been completed where coarse gold was suspected to be present. * RC and many of the RH, AC and RAB samples have been riffle split if dry. Wet samples have been sub-sampled using trowels. * Diamond core has been sawn in half, with half core submitted for assay. ------------------------------------------------------------ ---------------------------------------------------------------- Drilling techniques * Drill type (e.g. core, reverse circulation, open-hole * Drill methods include AC, RH and RAB in hammer, rotary air blast, auger, Bangka, sonic, etc) unconsolidated regolith and aircore hammer in hard and details (e.g. core diameter, triple or standard rock. Some shallow RC holes have been drilled in tube, depth of diamond tails, face-sampling bit or place of AC and RAB. other type, whether core is oriented and if so, by what method, etc). * Hole diameter for AC was 90 mm. RC hole diameters were generally 4.5 to 5.5 inch with face sampling hammers employed. * Diamond core was HQ/ NQ2 diameter. * Data from AC and RAB holes have not been used for resource estimation. ------------------------------------------------------------ ---------------------------------------------------------------- Drill sample recovery * Method of recording and assessing core and chip * Qualitative assessment of sample recovery and sample recoveries and results assessed. moisture content of all drill samples has been recorded. * Measures taken to maximise sample recovery and ensure representative nature of the samples. * Sample cyclone cleaned at end of each hole and as required to minimise down-hole and cross-hole contamination. * Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse * Core recovery has not been calculated in early material. diamond holes. Core recovery has been recorded in the 2015 diamond drilling and was very high. * No relationship is known to exist between sample recovery and grade. * Results of three twinned RC and diamond core hole pairs indicates that RC samples may be under-sampling gold, as the diamond core holes returned between 30% and 70% higher grades for equivalent intervals. ------------------------------------------------------------ ---------------------------------------------------------------- Logging * Whether core and chip samples have been geologically * All drillholes have been geologically logged by and geotechnically logged to a level of detail to on-site geologist, with lithological, mineralogical, support appropriate Mineral Resource estimation, weathering, alteration, mineralisation and veining mining studies and metallurgical studies. information recorded. The drillholes have not been geotechnically logged, except for basic BPM and RQD on the three diamond drillholes completed in 2015. * Whether logging is qualitative or quantitative in
nature. Core (or costean, channel, etc) photography. * Geological logging is qualitative. * The total length and percentage of the relevant intersections logged. * Chip trays containing 2 m sub-samples from AC, RAB and RC drillholes have been collected and photographed at the completion of the drilling programme. * 100% of any reported intersections (and of all metres drilled) have been geologically logged. ------------------------------------------------------------ ---------------------------------------------------------------- Sub-sampling techniques * If non-core, whether riffled, tube sampled, rotary * Diamond core has been sawn in half to present a 1/2 and sample split, etc and whether sampled wet or dry. core assay sample. Duplicates have been 1/4 core preparation sawn. * For all sample types, the nature, quality and appropriateness of the sample preparation technique. * Samples from AC, RAB and "bedrock" RC holes have been collected initially as 6 m composites followed by 1 m re-splits. Many of the 1 m re-splits have been * Quality control procedures adopted for all collected by riffle splitting. sub-sampling stages to maximise representivity of samples. * RC samples have been collected by riffle splitting if dry, or by trowel if wet. * Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field * Recent RC sampling has been split by cone splitter duplicate/second-half sampling. (12.5% Split) and 1m samples through prospective zones have been submitted to the laboratory. * Whether sample sizes are appropriate to the grain size of the material being sampled. * Laboratory sample preparation included drying, crushing if 1/2 core, and pulverising of submitted sample to target of P80 at 75 um. * Pulverised samples have been routinely checked for size after pulverising. * Laboratory analytical charge size included 30 g and 50 g standard sizes which are considered adequate for the material being assayed, although the presence of coarse gold was suspected in some samples based on variability in grade of multiply assayed samples. ------------------------------------------------------------ ---------------------------------------------------------------- Quality of assay data * The nature, quality and appropriateness of the * Standard laboratory analyses completed for gold (fire and assaying and laboratory procedures used and whether assay). laboratory the technique is considered partial or total. tests * The laboratory analytical methods used are considered * Nature of quality control procedures adopted (e.g. to be total. standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (i.e. lack of bias) and precision have been * For laboratory samples the Company introduced QAQC established. samples (standards and duplicates) at a ratio of one QAQC sample for every 22 to 24 drill samples. The laboratory additionally introduced QAQC samples (blanks, standards, checks). * Both the Company and laboratory QAQC samples indicate acceptable levels of accuracy and precision have been established. ------------------------------------------------------------ ---------------------------------------------------------------- Verification of sampling * The verification of significant intersections by * The Company has submitted a substantial number of and assaying either independent or alternative company personnel. significant intersection as well as QAQC Standard and Blanks to a third Party "Umpire" laboratory. * The use of twinned holes. * Three RC holes at Barns have been twinned with diamond holes. Results showed that grades were on * Documentation of primary data, data entry procedures, average higher than the RC holes. data verification, data storage (physical and electronic) protocols. * At Baggy Green there has been 1 RC hole "twinned" with a diamond hole in 2015, Grades are comparable * Discuss any adjustment to assay data. between holes. * There have been no twinned holes completed at White Tank. * The Company has not had umpire assay checks completed on any White Tank material but has verified the laboratory competencies with umpire checks from other nearby prospects (Barns and Baggy Green). The competent person and another company geologist have checked the results as well. * Andromeda Metals uses a Maxwell's Datashed database to store and validate its drilling data. * No adjustments have been made to the laboratory assay data. ------------------------------------------------------------ ---------------------------------------------------------------- Location of data points * Accuracy and quality of surveys used to locate * Drillhole collars have normally been pegged using drillholes (collar and down-hole surveys), trenches, DGPS with an accuracy of +/-0.5 m. mine workings and other locations used in Mineral Resource estimation. * Downhole surveys have been completed for deeper RC and diamond drillholes.
* Specification of the grid system used. * The co-ordinate system used during the historic * Quality and adequacy of topographic control. exploration programme was AMG84 Zone 53. * Since this time the coordinates have been converted into MGA94 Zone 53 datum. * Collar RLs have been created from a high resolution DTM, acquired from a geophysical survey. ------------------------------------------------------------ ---------------------------------------------------------------- Data spacing and * Data spacing for reporting of Exploration Results. * Drill lines at Barns have been drilled mainly on a 50 distribution m section spacing with some sections having been drilled 25 m apart. Drillhole spacings on section * Whether the data spacing and distribution is vary but on average are in the order of 20 m apart. sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and * Drill lines at Baggy Green have been drilled mainly classifications applied. on a 50 m section spacing. Drillhole spacing on section vary but on average are in the order of 20 to 50 m apart. * Whether sample compositing has been applied. * Drill lines at White Tank have been drilled mainly on a 50 m section spacing. Drillhole spacing on section vary but on average are in the order of 10 to 50 m apart. * The assay data has been composited for resource estimation purposes. ------------------------------------------------------------ ---------------------------------------------------------------- Orientation of data in * Whether the orientation of sampling achieves unbiased * Drill lines oriented east-west at Barns and Baggy relation to sampling of possible structures and the extent to Green. geological which this is known, considering the deposit type. structure * Drill lines initially oriented east--west then * If the relationship between the drilling orientation changed to northwest-southeast at White Tank. and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. * It remains unknown if internal mineralised structures exist at different orientations to the overall strike of mineralisation at Barns and Baggy Green. * Evidence from a drill traverse with 10 m hole spacing is that high grade shoots of gold are present in the overall plane of mineralisation at White Tank. ------------------------------------------------------------ ---------------------------------------------------------------- Sample security * The measures taken to ensure sample security. * Company staff collected or supervised the collection of all laboratory samples. * Samples submitted to the laboratory samples have been transported by a local freight contractor. * There exists no suspicion that the historic samples have been tampered with at any stage. ------------------------------------------------------------ ---------------------------------------------------------------- Audits or reviews * The results of any audits or reviews of sampling * There have been no external audits or reviews of the techniques and data. sampling techniques and data. ------------------------------------------------------------ ----------------------------------------------------------------
Section 2 Reporting of Exploration Results
Criteria JORC Code explanation Commentary Mineral tenement and * Type, reference name/number, location and ownership * The Barns and White Tank deposits are within EL 5092 land tenure including agreements or material issues with third and is owned 100% by Peninsula Resources limited, a status parties such as joint ventures, partnerships, wholly owned subsidiary of Andromeda Metals Limited. overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. * The Baggy Green deposit is within EL5120, owned 100% by Peninsula Resources limited, a wholly owned subsidiary of Andromeda Metals Limited. * 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. * Newcrest Mining Limited retains a 1.5% NSR royalty over future mineral production from both licences. * The Barns and White Tank deposits are on Perpetual Leasehold land used for cereal cropping. * Native Title is extinguished on Perpetual Leasehold land (Barns and White Tank). * A Native Title Agreement has been negotiated with the NT Claimant and has been registered with the SA Government. * Aboriginal heritage surveys have been completed over the Barns and White Tank deposit areas with no sites located in the immediate vicinity of the deposits. * A Compensation Agreement is in place with the relevant agricultural landowner. * Baggy Green is located within Pinkawillinnie Conservation Park. Native Title Agreement has been negotiated with the NT Claimant and has been registered with the SA Government. * Aboriginal heritage surveys have been completed over
the Baggy Green project area, with no sites located in the immediate vicinity. * A Native Title Agreement is in place with the relevant Native Title party. --------------------------------------------------------------- ------------------------------------------------------------- Exploration done by other * Acknowledgment and appraisal of exploration by other * On-ground exploration completed prior to Andromeda parties parties. Metals' work was limited to 400 m spaced soil geochemistry completed by Newcrest Mining Limited over the Barns prospect. * Other than the flying of regional airborne geophysics and coarse spaced ground gravity, there has been no recorded exploration in the vicinity of the Baggy Green deposit prior to Andromeda Metals' work. --------------------------------------------------------------- ------------------------------------------------------------- Geology * Deposit type, geological setting and style of * The deposits are considered to be either a lode gold mineralisation. or intrusion related mineralisation related to the 1,590 Ma Hiltaba/GRV tectonothermal event. * Gold mineralisation is associated with significant alteration of host rocks. --------------------------------------------------------------- ------------------------------------------------------------- Drillhole Information * A summary of all information material to the * Exploration results are not being reported for the understanding of the exploration results including a Mineral Resources areas. tabulation of the following information for all Material drillholes: * easting and northing of the drillhole collar * elevation or RL (elevation above sea level in metres) of the drillhole collar * dip and azimuth of the hole * down hole length and interception depth * hole length. --------------------------------------------------------------- ------------------------------------------------------------- Data aggregation * In reporting Exploration Results, weighting averaging * Exploration results are not being reported for the methods techniques, maximum and/or minimum grade truncations Mineral Resources areas. (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. * Metal equivalent values have not been used. --------------------------------------------------------------- ------------------------------------------------------------- Relationship between * If the geometry of the mineralisation with respect to * Exploration results are not being reported for the mineralisation the drillhole angle is known, its nature should be Mineral Resources areas. widths and reported. intercept lengths * If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect. --------------------------------------------------------------- ------------------------------------------------------------- Diagrams * Appropriate maps and sections (with scales) and * Relevant diagrams have been included within the tabulations of intercepts should be included for any Mineral Resource report main body of text. significant discovery being reported These should include, but not be limited to a plan view of drillhole collar locations and appropriate sectional * Exploration results are not being reported for the views. Mineral Resources areas. --------------------------------------------------------------- ------------------------------------------------------------- Balanced reporting * Where comprehensive reporting of all Exploration * Exploration results are not being reported for the Results is not practicable, representative reporting Mineral Resources areas. of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. --------------------------------------------------------------- ------------------------------------------------------------- Other substantive * Other exploration data, if meaningful and material, * Exploration results are not being reported for the exploration should be reported including (but not limited to): Mineral Resources areas. data geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. --------------------------------------------------------------- ------------------------------------------------------------- Further work * The nature and scale of planned further work (e.g. * Infill and extensional drilling aimed at growing the tests for lateral extensions or depth extensions or resource and converting Inferred resources to large-scale step-out drilling). Indicated resources is planned. --------------------------------------------------------------- -------------------------------------------------------------
Section 3 Estimation and Reporting of Mineral Resources
Criteria JORC Code explanation Commentary Database integrity * Measures taken to ensure that data has not been * The drillhole database is managed in-house by company corrupted by, for example, transcription or keying geologists using Maxwell's Datashed Data Management errors, between its initial collection and its use System. for Mineral Resource estimation purposes. * It has been validated by several company geologists * Data validation procedures used. and database administrators. * Data has been imported from current and historical data files. * Source data for historical drilling has been verified as being drilled by Andromeda Metals and imported directly into Datashed. * Additional data validation, by Optiro, included checking for out of range assay data and overlapping or missing intervals. ------------------------------------------------------------- ---------------------------------------------------------------- Site visits * Comment on any site visits undertaken by the * Mrs C Standing has not visited the Wudinna Gold
Competent Person and the outcome of those visits. Project. ------------------------------------------------------------- ---------------------------------------------------------------- Geological interpretation * Confidence in (or conversely, the uncertainty of) the * The weathering interpretation has been used to guide geological interpretation of the mineral deposit. the segregation of the mineralisation into primary and supergene zones, which have been treated separately in the estimation. * Nature of the data used and of any assumptions made. * As the host lithology is relatively homogenous, this * The effect, if any, of alternative interpretations on has not been used to guide the primary mineralisation Mineral Resource estimation. interpretation. * The use of geology in guiding and controlling Mineral * These resource estimates investigate an alternative Resource estimation. interpretation to the 2016 (Barns) and 2017 (White Tank and Baggy Green) resource estimates. * The factors affecting continuity both of grade and geology. ------------------------------------------------------------- ---------------------------------------------------------------- Dimensions * The extent and variability of the Mineral Resource * The Barns resource has an extent of 400 mN by 250 mE expressed as length (along strike or otherwise), plan and is up to 200 m deep. width, and depth below surface to the upper and lower limits of the Mineral Resource. * The White Tank resource has an extent of 250mN by 150 mE and is up to 120 m deep. * The Baggy Green resource has two areas of mineralisation with extents of 200 mN by 400 mE and 150 mN by 300 mE. The mineralisation extends to a depth of 200 m. ------------------------------------------------------------- ---------------------------------------------------------------- Estimation and modelling * The nature and appropriateness of the estimation * Data analysis and estimation was undertaken using techniques technique(s) applied and key assumptions, including Snowden Supervisor and Datamine software. treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer * Drillhole sample data was flagged from mineralised assisted estimation method was chosen include a interpretations. description of computer software and parameters used. * Mineralisation interpretation were extended to half * The availability of check estimates, previous the drill spacing and up to 15 m along strike. estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. * Sample data was composited to a 1 m downhole length. * The assumptions made regarding recovery of * The data has a moderate to high coefficient of by-products. variation and high-grade outliers are present. Top-cut grades of 4 to 19 g/t gold were applied to the supergene mineralisation and 19 to 25 g/t gold to * Estimation of deleterious elements or other non-grade the fresh mineralisation. The top-cut grades were variables of economic significance (e.g. sulphur for selected by examining histograms, log probability acid mine drainage characterisation). plots, population disintegration. * In the case of block model interpolation, the block * The Mineral Resources were estimated by Mining Plus size in relation to the average sample spacing and in 2016 (Barns) and 2017 (White Tank and Baggy the search employed. Green). These resources were interpreted using a higher nominal cut-off grade and have different letteral extents and mineralisation continuity * Any assumptions behind modelling of selective mining orientations. The global difference is small (5% more units. contained gold in the 2019 model) and the tonnage and grade variances for the individual deposits are consistent with the differences applied to the * Any assumptions about correlation between variables. interpretation and resource estimation process. * Description of how the geological interpretation was * No assumptions have been made regarding the recovery used to control the resource estimates. of by-products. * Discussion of basis for using or not using grade * Only gold has been estimated. cutting or capping. * Gold mineralisation continuity was interpreted from * The process of validation, the checking process used, variogram analyses to have along strike (or the comparison of model data to drillhole data, and down-plunge) ranges of 26 m to 53 m, across strike use of reconciliation data if available. (or down-dip) ranges of 42 m to 75 m and vertical (or perpendicular to the mineralisation plane) of 4.5 to 13 m. * Grade estimation at Barns and White Tank was into parent blocks of 10 mE by 10 mN on 4 m benches and at Baggy Green was into a parent block of 20 mE by 20 mN on 5 m benches. Block sizes were selected based on kriging neighbourhood analysis. * Estimation was carried out using ordinary kriging at the parent block scale. * The search ellipses were oriented within the plane of the mineralisation. * Three estimation passes were used; the first search was based upon the variogram ranges in the three principal directions; the second search was two times the initial search and the third search was five to six times the second search, with reduced sample
numbers required for estimation. * At Barns, around 62% of the block grades were estimated in the first pass, 29% in the second pass and 9% in the third search pass. At White Tank, around 81% of the block grades were estimated in the first pass, 17% in the second pass and 2% in the third search pass. At Baggy Green, around 21% of the block grades were estimated in the first pass, 43% in the second pass and 35% in the third search pass. * The estimated gold block model grades were visually validated against the input drillhole data, comparisons were carried out against the drillhole data and by northing, easting and elevation slices. Moisture * Whether the tonnages are estimated on a dry basis or * Tonnes have been estimated on a dry basis. with natural moisture, and the method of determination of the moisture content. Cut-off parameters * The basis of the adopted cut-off grade(s) or quality * The Barns, Baggy Green and White Tank Mineral parameters applied. Resource estimates have been reported at a cut-off grade of 0.5 g/t gold, which is considered appropriate for the likely open pit mining method. ------------------------------------------------------------- ---------------------------------------------------------------- Mining factors or assumptions * Assumptions made regarding possible mining methods, * Planned extraction is by open pit mining. minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining * Mining factors such as dilution and ore loss have not reasonable prospects for eventual economic extraction been applied. to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. ------------------------------------------------------------- ---------------------------------------------------------------- Metallurgical factors or * The basis for assumptions or predictions regarding * No metallurgical assumptions have been built into the assumptions metallurgical amenability. It is always necessary as resource models. part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. ------------------------------------------------------------- ---------------------------------------------------------------- Environmental factors or * Assumptions made regarding possible waste and process * No assumptions have been made regarding waste and assumptions residue disposal options. It is always necessary as process residue. part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. ------------------------------------------------------------- ---------------------------------------------------------------- Bulk density * Whether assumed or determined. If assumed, the basis * A total of 255 bulk density determinations have been for the assumptions. If determined, the method used, undertaken at Barns on either historical or recent whether wet or dry, the frequency of the measurements, drillholes. the nature, size and representativeness of the samples. * The Barns deposit is 1 km north of White Tank and the bulk density determinations are considered valid for * The bulk density for bulk material must have been White Tank. measured by methods that adequately account for void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones within * A total of 185 bulk density determinations have been the deposit. undertaken at Baggy Green on either historical or recent drillholes. * Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. * Average values have been calculated from the dataset and applied to the resource model based on the oxidation/weathering state and lithologies in the area * Bulk density measurements were calculated by water displacement method. * Density values assigned to the resource model range from 2.52 t/m(3) to 2.73 t/m(3) . ------------------------------------------------------------- ---------------------------------------------------------------- Classification * The basis for the classification of the Mineral * The Mineral Resources have been classified on the Resources into varying confidence categories. basis of confidence in geological and grade continuity and taking into account data quality, data density and confidence in the grade estimation (using * Whether appropriate account has been taken of all the modelled grade continuity and the slope of the relevant factors (i.e. relative confidence in regression as criteria). tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). * The Mineral Resources at White Tank and Baggy Green have been classified as Inferred. * Whether the result appropriately reflects the Competent Person's view of the deposit. * Indicated Mineral Resources have been defined at Barns within four of the fresh mineralisation domains in areas where drill spacing is generally 20 mE by 50 m or less and the resources are above 40 mRL. * Inferred Mineral Resources have been defined at Barns in areas where extension of mineralisation is
supported by the drilling. * The classification considers all available data and quality of the estimate and reflects the Competent Person's view of the deposit. ------------------------------------------------------------- ---------------------------------------------------------------- Audits or reviews * The results of any audits or reviews of Mineral * The 2019 Mineral Resource estimates for Barns, White Resource estimates. Tank and Baggy Green have not yet been audited by an external party. * Optiro understands the SRK consulting will be reviewing the Mineral Resource estimates for Cobra Resources PLC. ------------------------------------------------------------- ---------------------------------------------------------------- Discussion of relative * Where appropriate a statement of the relative * The assigned classification of Indicated and Inferred accuracy/ accuracy and confidence level in the Mineral Resource reflects the Competent Person's assessment of the confidence estimate using an approach or procedure deemed accuracy and confidence levels in the Mineral appropriate by the Competent Person. Resource estimate. * The statement should specify whether it relates to * The statement relates to global estimates of tonnes global or local estimates, and, if local, state the and grade. relevant tonnages, which should be relevant to technical and economic evaluation. * No production data exists for the Wudinna Project gold deposits. ------------------------------------------------------------- ----------------------------------------------------------------
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May 07, 2019 02:01 ET (06:01 GMT)
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