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. |
All results reported are from Reverse Circulation (RC) drill samples collected over one metre (1m) intervals. Multiple methods were used to determine uranium mineralisation intervals including down hole gamma analysis, hand held scintillometer measurements and portable XRF analysis. Intervals containing uranium mineralisation were selected and submitted for laboratory assay analysis. |
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Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. |
Standards and blanks are inserted into the sample stream to assess the accuracy, precision and methodology of the external laboratories used. In addition, field duplicate samples are inserted to assess the variability of the uranium mineralisation. Approximately 15-20% of all samples relate to quality control. In addition, the laboratories undertake their own duplicate sampling as part of their internal QA/QC processes. Examination of the QA/QC sample data indicates satisfactory performance of field sampling protocols and assay laboratories providing acceptable levels of precision and accuracy. Drill hole collar locations are surveyed by qualified surveyors (Cubica Ingeniería Metrica S.L) using standard differential GPS (DGPS) equipment achieving sub decimetre accuracy in horizontal and vertical position. Down-hole surveys are undertaken using a Geovista down-hole deviation probe. Measurements are taken every 1cm down hole and averaged every 10m. No strongly magnetic rocks are present within the deposit which may affect magnetic based readings. |
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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. |
RC drill samples are collected over 1m intervals, manually homogenised before being split on site using a three tier riffle splitter to provide an approximate 3-5kg sample. In rare cases, wet samples are split using a cone and quarter method. Scintillometer measurements are taken on all samples and this data is used to select the samples to be sent to external laboratories for sample preparation and analysis. Indicative mineralised intervals are determined from this data and the sampling extended up and down hole by at least 2-5m. Samples are further split in the core shed using a scoop such that 0.7-1kg samples are sent to the preparation laboratories of ALS and AGQ (Seville, Spain) and analytical laboratory of ALS (Loughrea, Ireland). Samples are dried, fine crushed down to 70% below 2mm, split to obtain 250g and pulverised with at least 85% of the sample passing 75µm. 10g of sample is used for uranium analysis by pressed powder X-ray fluorescence (XRF) method. |
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). |
Drilling was by the RC method drilling using a 140mm diameter face sampling hammer. |
Drill sample recovery |
Method of recording and assessing core and chip sample recoveries and results assessed. |
RC drill samples are collected over 1m intervals through a cyclone. Plastic sample bags are strapped to the cyclone to maximise sample recovery. Individual sample bags are not weighed to assess sample recovery but a visual inspection is made by the Company geologist to ensure all samples are of approximately equivalent size. |
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Measures taken to maximise sample recovery and ensure representative nature of the samples. |
The RC drilling rigs utilised suitably sized compressors to ensure dry samples where possible. Plastic sample bags are strapped to the cyclone to maximise sample recovery. Sample logs record whether the sample is dry, moist or wet. |
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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. |
There is no known relationship between sample recovery and grade. The RC sample recoveries are of an acceptable level and no bias is expected from any sample losses. |
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. |
Geological logging of RC chip samples includes recording descriptions of lithology, weathering, alteration and mineralisation. A scintillometer reading of counts per second (cps) is recorded for each 1m sample (quantitative). |
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Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. |
Geological logging is qualitative in nature. RC samples and chip trays are photographed. |
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The total length and percentage of the relevant intersections logged. |
All RC drill holes are logged in full by Company geologists. |
Sub-sampling techniques |
If core, whether cut or sawn and whether quarter, half or all core taken. |
Not Applicable - RC drilling only. |
and sample preparation |
If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. |
RC drill samples are collected at 1m intervals. RC intervals are sampled by splitting dry samples in the field to 3-5kg using a three tier riffle splitter and further split in the core shed to 0.7-1kg using a scoop. Where samples are wet they are dried prior to spitting. In rare cases, wet samples are split using a cone and quarter method. |
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For all sample types, the nature, quality and appropriateness of the sample preparation technique. |
Samples are sent to ALS and AGQ laboratories for preparation. Samples are dried, fine crushed down to 70% below 2mm and pulverised with at least 85% of the sample passing 75µm. 10g of sample is used for uranium analysis by pressed powder XRF method. This is considered appropriate for this style of uranium mineralisation. |
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Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples. |
Previous field tests have determined that the sample size and method of sampling produce representative RC samples. QA/QC procedures involve the use of standards, duplicates and blanks which are inserted into sample batches at a frequency of approximately 15-20%. |
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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. |
Duplicate splits of RC samples are taken every 10m down hole within the sampled intervals. The results from these duplicates generally show acceptable repeatability, however indications of inhomogeneity were observed in a number of duplicates. |
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Whether sample sizes are appropriate to the grain size of the material being sampled. |
The uranium is typically very fine grained. Previous test work carried out by Berkeley using different sample sizes has demonstrated that the selected sample size is appropriate. |
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. |
Uranium analysis by pressed powder XRF method. This analytical method reports total uranium content. |
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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. |
Down-hole gamma logging is undertaken for all probe accessible drill holes to provide eU3O8 ("equivalent" U3O8 grade) data however, it is not currently considered of sufficient quality to replace chemical assay data for the purposes of reporting drilling results at Zona 7. The drill intersections reported in this release are calculated using only chemical assay data. |
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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. |
Standards, blanks and duplicates are regularly inserted into the sample stream with approximately 15-20% of all samples related to quality control. The external laboratories used also maintain their own process of QA/QC utilising standards, pulp repeats, sample duplicates and blanks. Review of the Berkeley quality control samples, as well as the external laboratory quality QA/QC reports, has shown no sample preparation issues, acceptable levels of accuracy and precision and no bias in the analytical datasets. |
Verification of sampling and assaying |
The verification of significant intersections by either independent or alternative company personnel. |
Reported significant intersections have been checked and verified by Senior Geological management. |
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The use of twinned holes. |
No twinned holes were drilled in the current RC drilling programme. |
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Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. |
All primary data is recorded in templates designed by Berkeley. Assay data from the external laboratory is received in spreadsheets and downloaded directly into an Access Database managed by the Company. Data is entered into controlled excel templates for validation. The validated data is then loaded into a password secured relational database by a designated Company geologist. Daily backups of all digital data are undertaken. These procedures are documented in the Berkeley Technical Procedures and Protocols manual. |
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Discuss any adjustment to assay data. |
Uranium (ppm) assays received from the external laboratory are converted to U3O8 (ppm) using the stoichiometric factor of 1.179. |
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. |
Drill hole collar locations are surveyed by qualified surveyors (Cubica Ingeniería Metrica S.L) using standard differential GPS (DGPS) equipment achieving sub decimetre accuracy in horizontal and vertical position. Down-hole surveys are undertaken using a Geovista down-hole deviation probe. Measurements are taken every 1cm down hole and averaged every 10m. No strongly magnetic rocks are present within the deposit which may affect magnetic based readings. |
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Specification of the grid system used. |
The grid system is ETRS 1989 UTM Zone 29N. |
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Quality and adequacy of topographic control. |
Topographic control is based on a digital terrain model with sub metric accuracy sourced from the Spanish Geographical Institute (Instituto Geográfico Nacional) and is verified through detailed drill hole collar surveys by a qualified surveyor using a DGPS. |
Data spacing and distribution |
Data spacing for reporting of Exploration Results. |
This RC drilling programme has been designed to close the current broadly spaced drill pattern down to a notional 50m by 50m grid. |
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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. |
The data spacing (notionally 50m by 50m) is considered sufficient to assume geological and grade continuity, and will allow the estimation of Indicated Mineral Resources. |
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Whether sample compositing has been applied. |
No compositing of RC samples in the field has been undertaken. |
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. |
The mineralised zone strikes northeast-southwest and is interpreted to be sub-horizontal (due to post mineralisation supergene processes) to shallowly dipping. |
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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. |
All of the RC drill holes reported in this release are vertical. Due to the interpreted flat lying nature of the mineralisation, no sampling bias is considered to have been introduced by the orientation of the drilling. |
Sample security |
The measures taken to ensure sample security. |
Chain of custody is managed by Berkeley. Samples are transported from the drill site by Company vehicle to a sample preparation shed where samples are prepared for dispatch. Samples are sent directly from the sample preparation shed to the laboratory using a certified courier or a Berkeley owned vehicle authorised for radioactive materials transport. No other freight is transported with the samples which are taken directly from the Berkeley facility to the external laboratory. Sample submission forms are sent in paper form with the samples as well as electronically to the laboratory. Reconciliation of samples occurs prior to commencement of sample preparation for assaying. |
Audits or reviews |
The results of any audits or reviews of sampling techniques and data. |
Sampling techniques and procedures, as well as QA/QC data, are reviewed internally an ongoing basis. Mr Malcolm Titley (Geology Consultant, Maja Mining Limited) has independently reviewed the sampling techniques, procedures and data. He has undertaken a site visit to review and inspect the application of procedures. These reviews have concluded that the sampling and analytical results have resulted in data suitable for incorporation into Mineral Resource estimation. |