27 Oct 2015 09:01
RNS Number : 5318D
W Resources PLC
27 October 2015
27 October 2015
W Resources Plc
("W" or the "Company")
76% Increase in JORC Indicated Resource Tonnage at Régua
W Resources Plc (AIM:WRES), a tungsten, copper and gold exploration and development company announces a significant increase in the contained tungsten within the JORC compliant mineral resource estimate at Régua, located in Northern Portugal, following the completion of the new mineral resource estimate by Golder Associates.
The total resource tonnage increased by 22% to 5.46mt at a grade of 0.28% WO3, up from 4.46mt, and notably the indicated resource tonnage increased by 76% to 3.76mt at 0.304% WO3 (2012: 2.14mt @ 0.367% WO3).
2015 mineral resource estimate for the Régua Deposit using a 0.1% WO3 Cut-Off Grade within mineralised domains
Tonnes (Mt) | WO3 % | Contained WO3 (mtu) | |
Indicated | 3.76 | 0.304 | 1,143,040 |
Inferred | 1.70 | 0.227 | 385,900 |
Total | 5.46 | 0.280 | 1,528,800 |
Source: Golder Associates Document No. 1526105-001-L-Rev0
The updated resource model is based on thick high-grade sections of tungsten mineralisation at or near surface and will form the basis for mine planning and mine reserve estimation. The outcrop area drilled mid-year has the potential for low cost high-grade open pit development.
Michael Masterman, Chairman of W Resources commented: "The drilling campaign at Régua exceeded our initial expectations and we are delighted that the work to date has resulted in this significant increase in the indicated resources at Régua. The results to date provide us with a strong basis for the next phase of mine planning as we move the project nearer to production."
The next step is now to complete the mine planning and reserve estimation process, which is targeted for the first quarter 2016. Metallurgical work has progressed well over the last quarter with good metal recoveries. A full update on the metallurgical programme and results will be provided in the next two months.
Summary of Mineral Resource Statement
The mineral resource inventory was classified as either Indicated or Inferred Resources. The classification of the mineral resources was considered appropriate based on geological confidence criteria and the location and quality of drilling and sampling information.
The resource estimate is based on the Ordinary Kriging interpolated block model.
The mineral resource consists of mineralised skarn horizons hosted within calcsilicate-altered schists and greywackes. The deposit is cross cut by a fault splitting the deposit into two separate areas. The skarn units continue across the fault although the orientation of the mineralisation is different for each fault block. A WO3 cut-off grade of 0.1% was applied to the mineral resource estimate.
The information in the statement which relates to the mineral resource is based on information compiled in accordance with the JORC Code, 2012 Edition.
Enquiries:
W Resources Plc Michael Masterman T: +44 (0) 20 7193 7463 www.wresources.co.uk | Grant Thornton UK LLP Colin Aaronson / Jen Clarke / Harrison Clarke T: +44 (0) 20 7383 5100 |
SI Capital - Joint Broker Andy Thacker / Nick Emerson T: +44 (0) 1483 413500 www.sicapital.co.uk | Gable Communications Justine James T: +44 (0) 20 7193 7463 M: +44 (0) 7525 324431 |
Northland Capital Partners - Joint Broker John Howes / Abigail Wayne (Corporate Broking) T: +44 (0) 20 7382 1100 www.northlandcp.co.uk |
About Régua
W Resources Plc (AIM:WRES) owns a permit for the exploration of the Régua tungsten deposit located 400km North of Lisbon and 95km East of Porto in the municipality of the town of Armamar. The Company was awarded a trial mining licence by the Portuguese Ministry for the Environment, Territorial Planning and Energy in June 2014.
Régua tungsten deposit has a resource of 5.46 million tonnes grading 0.28% WO3, at a cut-off of 0.1% WO3, covering an area of 8km². The deposit has not been previously mined and is located close to infrastructure with good road access.
Technical information in this report and on the W website has been prepared in accordance with the JORC Code or defined by National Instrument 43-101 and approved for inclusion by Mr José Mario Castelo Branco, EuroGeol, who is a "qualified person" in respect of the AIM Rules for Companies with over 32 years' experience in the Exploration and Mining Geology industry. Mr Castelo Branco holds a B.Sc. in Geology from the University of Porto in Portugal. He is also a member of the Portuguese Association of Geologists (Number 354), the European Federation of Geologists, the Society of Economic Geologists, the Society for Geology Applied to Mineral Deposits and the Prospectors and Developers Association of Canada.
The JORC Code Assessment Criteria
The JORC Code, 2012 Edition describes a number of criteria, which must be addressed in the Public Reporting of Mineral Resource estimates. These criteria provide a means of assessing whether or not parts of or the entire data inventory used in the estimate are adequate for that purpose. The Mineral Resource estimates stated in this document were based on the criteria set out in Table 1 of that Code. These criteria are discussed in Table 2 as follows.
Table 2: JORC Code Table 1.
JORC Code Assessment Criteria | Comment |
Section 1 Sampling Techniques and Data | |
Sampling Techniques | ¡ Rock chip sampling from outcrops and trenches was performed to determine whether prospective tungsten mineralised lithology (skarn) may yield any anomalous tungsten values and not to determine average grades. ¡ Samples weighing from 500 g to 1 kg were taken from each sampling location, and its position was recorded with a hand-held GPS. ¡ Diamond drilling was used to obtain core samples. ¡ Sampled intervals included visual scheelite bearing mineralised skarns identified under UV light and two 1 metre samples taken immediately above and immediately below the mineralised sample. ¡ All rock samples were bagged for shipment to the laboratory inside cotton bags with the number written on the outside. The cotton bag is put in a plastic bag which includes a tag with the sample number inside as well as the same number written on the outside of the plastic bag, in both cases in waterproof ink. |
Nature and quality of sampling (e.g. cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as downhole 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 (e.g. ‘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 (e.g. submarine nodules) may warrant disclosure of detailed information. | |
Drilling Techniques | ¡ Core was obtained with an Acker drill rig with wireline capability. ¡ B146 (132 mm recovered core) was used for ensuring high recovery along the weathered/fractured surficial rock mass, while otherwise PWL (85 mm recovered diameter) and HWL (63.5 mm recovered core) was used. ¡ All drill holes were surveyed at the collar surface by high-resolution topographic survey. Data for Eastings, Northings and RL was recorded in PT‑TM06/ETRS89, WGS84-UTM-ZONE29N. ¡ All drill holes have been subject to downhole surveying, to record variations from the original inclination. ¡ Surveys have been recorded at varying intervals, using EZ-Trac from Reflex Instruments. ¡ Core was oriented in selected holes using ACT II RD from Reflex Instruments. |
Drill type (e.g. core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc.), and details (e.g. 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.). | |
Drill Sample Recovery | ¡ Sample recovery was assessed visually, recorded onto a logging sheet, photographed and inserted in an Excel spreadsheet. |
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. | |
Logging | ¡ Logging was performed after core fragment “puzzle” reconstruction, and a line was marked down the centre of the core. ¡ Diamond core was geotechnically logged, and complete data (recovery, RQD, joint orientation, spacing, roughness and weathering) was recorded onto a logging sheet and inserted in an Excel spreadsheet. ¡ Diamond core was geologically logged, and complete data (lithology, alteration, structural data and mineralisation) was recorded onto a coded logging sheet and inserted in an Excel database. ¡ All drill holes have been logged in full. |
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. | |
Sub‑Sampling Techniques and Sample Preparation | ¡ The core was cut by diamond saw along a line marked down the centre of the core, splitting the core into two equal halves. One quarter of the PWL core and one half of the HWL core were sent for analysis and remaining core was retained in wooden core boxes for future reference. ¡ Half and quarter core samples were sent to ALS Laboratory in Seville, Spain for assaying ¡ At ALS facilities, samples were crushed (70% ¡ The following elements were included in the analysis: Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hf, Hg, In, K, La, Li, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Rb, Re, S, Sb, Sc, Se, Sn, Sr, Ta, Te, Th, Ti, Tl, U, V, W, Y, Zn, Zr, WO3. |
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. | |
Quality of Assay Data and Laboratory Tests | ¡ Short wave UV light was used to identify the presence of scheelite in the core but was not use as a quantitative or semi-quantitative method. ¡ Internationally certified standards and blanks were regularly introduced among core samples with frequency of 1 in 20 approximately. ¡ Internal laboratory cross checking methods are implemented by ALS. ¡ Assay data reported as per laboratory final reports and certificates. |
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 (e.g. standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (i.e. lack of bias) and precision have been established. | |
Verification of Sampling and Assaying | ¡ Verification of significant intersections by alternative company personnel. ¡ Primary logging paper sheets stored at office, data entered into Excel spreadsheets as is and coded, both stored in the server and in an external hard drive. ¡ All core boxes are photographed and a photo archive is maintained within the drilling database. |
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. | |
Location of Data Points | ¡ Drill hole collars survey by precision dGPS with GPRS on-line processing with 10 mm accuracy and Total Station. ¡ Grid system PT-TM06/ETRS89, WGS84-UTM-ZONE29N. ¡ Topographic information has been sourced from a publically available database ReNEP produced by Portuguese Geographic Institute. |
Accuracy and quality of surveys used to locate drill holes (collar and downhole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control. | |
Data Spacing and Distribution | ¡ Completed drill holes were designed for testing different targets and have irregular spacing. ¡ Data spacing is irregular but is close to 40 m by 40 m sufficient to establish Mineral Resource. ¡ Data spacing and distribution is currently considered by the Competent Person to be sufficient only for Indicated and Inferred Mineral Resources and thus currently not sufficient to support an Ore Reserve estimate. |
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. | |
Orientation of Data in Relation to Geological Structure | ¡ The orientation of drilling is approximately perpendicular to the strike of the mineralised bodies. ¡ The dip of the drill holes is not perpendicular to the true dip of the skarn bodies, so the intersections do not represent true widths. |
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. | |
Sample Security | ¡ Samples are kept in labelled wooden core boxes in a locked building. ¡ Industry standard practices are applied. |
The measures taken to ensure sample security. | |
Audits and Reviews | ¡ Golder has not undertaken audits or reviews of the sampling techniques and data. Golder is not aware of any audits or reviews carried out by other parties. |
The results of any audits or reviews of sampling techniques and data. | |
Section 2 Reporting of Exploration Results | |
Mineral Tenement and Land Tenure Status | ¡ Trial mine license CE-142 granted to Iberian Resources Portugal, Recursos Minerais, Unipessoal, Lda, 100% owned by W Resources Plc. |
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. | |
Exploration Done by Other Parties | ¡ Previous exploration activities in 1980’s by “Minas de Santa Leucádia, Lda” and “Rio Tinto Finance and Exploration, Ldt.”(Riofinex). |
Acknowledgment and appraisal of exploration by other parties. | |
Geology | ¡ Scheelite bearing skarns within impure carbonate horizons of a pre-Ordovican greywaque-schist sequence, which has been affected by contact metamorphism from Hercynian granites. |
Deposit type, geological setting and style of mineralisation. | |
Drill hole information | ¡ Not applicable. Exploration results have previously been reported. This Table relates to the reporting of the Mineral Resource estimates. |
Data aggregation methods | ¡ No maximum or minimum grade truncations were performed to the assay data ¡ No metal equivalents used or stated |
Relationship between mineralisation widths and intercept lengths | ¡ Drill intersections are not reported as true widths. |
Diagrams | ¡ Not applicable. Exploration results have previously been reported. This Table relates to the reporting of the Mineral Resource estimates. |
Balance reporting | ¡ Not applicable. Exploration results have previously been reported. This Table relates to the reporting of the Mineral Resource estimates. |
Other substantive exploration data | ¡ Not applicable. Exploration results have previously been reported. This Table relates to the reporting of the Mineral Resource estimates. |
Further work | ¡ Further work will include detailed interpretation of results and further diamond core drilling. |
Section 3 Estimation and Reporting of Mineral Resources | |
Database Integrity | ¡ All drilling data is contained in an Excel database and stored by Iberian Resources. Validation in the database is set to prevent the accidental duplication, alteration or deletion of records suitable for use during this resource estimate. |
Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. Data validation procedures used. | |
Site Visits | ¡ The Competent Person or a Golder representative to date has not visited the project site due to schedules and time constrains. A site visit will be completed prior to the commencement of the mining studies. |
Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken indicate why this is the case. | |
Geological Interpretation | ¡ Iberian Resources has carried out interpretation of the mineralisation and weathering. Iberian Resources is confident in the overall geological, weathering and mineralisation interpretation of the deposit. The mineralisation interpretation comprised 72 vertical sections aligned to azimuth N210. The interpretation was transferred to Golder as DXF sections however not-georeferenced. Golder interpretation was based on these geology sections and adapted where necessary. ¡ Three dimensional wireframe modelling were carried out using Vulcan® software. ¡ The mineralisation consists of mineralised skarn horizons hosted within calcsilicate-altered schists and greywackes. The deposit is cross-cut by a fault splitting the deposit into two separate areas. The skarn units continue across the fault although the orientation or the mineralisation is different for each fault block. A WO3 cut-off grade of 0.05% was applied for the modelling of mineralisation domains, which is below the 0.1% cut-off grade applied for Mineral Resource reporting |
Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology. | |
Dimensions | ¡ The mineralised zone is approximately 900 m long (north west-south east) by 400 m wide. The mineralisation goes from surface outcrop to approximately 300m below the surface in the deepest zone. |
The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. | |
Estimation and Modelling Techniques | ¡ The estimation technique used for the Mineral Resource estimation is the geostatistical method of Ordinary Kriging. Parameters were derived from variograms to estimate the average grade for WO3, AS and S. ¡ Block sizes were selected with respect to the nominal drilling spacing to ensure acceptable local estimation quality. ¡ The block size selected for each deposit is 10 m (X) by 10 m (Y) by 5 m (Z). The sub-block size is 1 m (X) by 1 m (Y) by 0.5 m (Z). ¡ All samples were composited to 2 m for estimation purposes. ¡ The estimation was conducted in three passes with the search size increasing for each pass. ¡ High grade spatial restraining was applied for grade estimation of individual domains. The threshold uses to restrict high grades was based on the assessment of sample statistics and probability plots. Restraining of high grades was to within 10 m by 10 m by 10 m distance. ¡ Each individual domain was estimate separately and an unfolding technique was applied for estimation to better capture mineralisation continuity within the domains ¡ The model was validated visually and statistically using comparisons to composite data statistics, swath plots and evaluation of the grade estimation smoothing effect. |
The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters, and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. The assumptions made regarding recovery of by‑products. Estimation of deleterious elements or other non‑grade variables of economic significance (e.g. sulfur for acid mine drainage characterisation). In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. Any assumptions behind modelling of selective mining units. Any assumptions about correlation between variables. Description of how the geological interpretation was used to control the resource estimates. Discussion of basis for using or not using grade cutting or capping. The process of validation, the checking process used, the comparison of model data to drill hole data, and use of reconciliation data if available. | |
Moisture | ¡ All Mineral Resource tonnages are reported on a dry basis. |
Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. | |
Cut-off Parameters | ¡ The resource model is constrained by assumptions about economic cut-off grades. The mineralisation is confined by a 0.05% WO3 cut-off grade. The tabulated resources were reported using cut-off grade of 0.1% WO3 which was applied on a block by block basis. |
The basis of the adopted cut-off grade(s) or quality parameters applied. | |
Mining Factors or Assumptions | ¡ The Mineral Resource estimation approach has assumed that mining will take place using an open pit, selective mining method. The vertical block size is 5 m, which forms the basis of the assumed vertical selectivity in the Mineral Resource estimate. |
Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. | |
Metallurgical Factors or Assumptions | ¡ No metallurgical assumptions have been made. |
The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as 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. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. | |
Environmental Factors or Assumptions | ¡ The municipality of Armamar has approved (early 2015) the new Land Use Plan. The Regua project area is included as potential for a future tungsten operation, so it is assumed that process and waste disposal infrastructures, as well as water storage, should be acceptable as part of any mining operation. And a baseline environmental study for the trial mine is about to begin to be presented to the authorities for obtaining the final mining license. |
Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. | |
Bulk Density | ¡ Bulk density values were assigned based on mineralisation and fault block. The bulk densities were based on immersion measurements from median density of 1 890 samples from 27 DDH were used in determining the assigned values. |
Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc.), moisture and differences between rock and alteration zones within the deposit. Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. | |
Classification | ¡ The Mineral Resources were classified according to the following criteria and assumptions: § Measured Resources: Due to the data scarcity and complexity of parts the mineralisation lode system, no Measured material has been defined for Regua deposit. § Indicated Resources: the area of Regua deposit classified as Indicated Resources; - Has a relative drill spacing of 50 by50 m or less - Mineralised domain intersected by more than 3 drill holes - Has a higher estimation confidence as reflected by the kriging slope of regression, generally above 0.6. § Inferred Resources: all remaining estimated blocks, generally represented by discontinuous and geologically complex zones with poor drilling coverage. ¡ Extrapolation of mineralisation from drill holes was limited to 20 m to 40 m, generally half of the nominal drill hole spacing on section. |
The basis for the classification of the Mineral Resources into varying confidence categories. Whether appropriate account has been taken of all relevant factors, i.e. relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data. Whether the result appropriately reflects the Competent Person(s)’ view of the deposit. | |
Audits or Reviews | ¡ This Mineral Resource estimate is an update to the previous estimates completed by Golder in 2012 and 2011. ¡ No audits or reviews have been undertaken on this Mineral Resource estimate. |
The results of any audits or reviews of Mineral Resource estimates. | |
Discussion of Relative Accuracy/Confidence | ¡ The revised Mineral Resource estimate represents a 22% or a million tonnes increase over the previous estimates. The increase in the total resource and higher resource confidence is attributable to improved definition to mineralised zones and extensions to mineralisation as a result of the completion of infill and extension diamond drilling. The addition of new samples has also improved the estimation performance. ¡ The relative accuracy is reflected in the Mineral Resource classification discussed above that is in line with industry acceptable standards |
Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. | |
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