Criteria | JORC Code explanation | Commentary |
Database integrity | - 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.
| - The database is managed using Micromine Geobank software. Data is logged directly into an Excel spread sheet logging system with drop down field lists. Validation checks are written into the importing program ensures all data is of high quality. Digital assay data is obtained from the Laboratory, QA/QC checked and imported. Geobank exported to CSV TEXT and imported directly to the Micromine software used for the MRE.
- The combined database was provided for the MRE.
- Validation of the data import include checks for the following:
- Duplicate drill hole or trench names,
- One or more drill hole collar or trench coordinates missing in the collar file,
- FROM or TO missing or absent in the assay file,
- FROM > TO in the assay file,
- Sample intervals overlap in the assay file,
- First sample is not equal to 0 m in the assay file,
- First depth is not equal to 0 m in the survey file,
- Several downhole survey records exist for the same depth,
- Azimuth is not between 0 and 360° in the survey file,
- Dip is not between 0 and 90° in the survey file,
- Azimuth or dip is missing in survey file,
- Total depth of the holes is less than the depth of the last sample,
- Total length of trenches is less than the total length of all samples.
- Negative sample grades.
- No logical errors were identified in the analytical data.
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Site visits | - 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.
| - Warren Potma, an employee of CSA Global, visited the Kharmagtai project, located in Mongolia, over 4 days from 18th to 22nd September 2018.
- The site visit was required for the purposes of inspection, ground truthing, review of activities, and collection of information and data.
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Geological interpretation | - 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.
| - Geological data has been collected in a consistent manner that has allowed the development of geological models to support the Mineral Resource estimate. Copper and gold mineralisation is controlled by porphyry phases, oxidation zone, level of veining, breccia, country rocks and barren dykes.
Full geological models of all major geological formations were developed for each deposit, and the block models were domained accordingly. Domaining of the deposit mineralisation was based on the current understanding of the deposits’ geology. All major geological formations were wireframed by Xanadu geologists using Leapfrog software, including porphyry phases, country rocks, barren dyke, base of oxidation surface and breccia bodies. All geological formations were domained by the level of development of stockwork - <0.5% veining, 0.5-1.5% veining and >1.5% veining. All provided wireframe models were imported into Micromine software and validated by CSA Global. - Geological interpretation and wireframing were based on sampling results of drill holes and trenches, which were logged at 2 m intervals (average).
- No alternative interpretations were adopted.
- Lithological logging was mainly used to interpret and to wireframe the geological formations. Geological logging of veining was used to wireframe the stockwork and breccia domains.
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Dimensions | - 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.
| - Altan Tolgoi: The strike length of the mineralised zone is about 1,200 m. Width is up to 800 m, no plunging, traced down dip to 1,030 m. Mineralisation is outcropped at the surface.
- Tsagaan Sudal: The strike length of the mineralised zone is about 1,200 m. Width is up to 730 m, no plunging, traced down dip to 1,080 m. Mineralisation is outcropped at the surface.
- Zesen Uul: The strike length of the mineralised zone is about 630 m. Width is up to 150 m with apparent plunging to SW at about 40 degrees. traced down dip to 420 m dipping 70 degrees to SE. Mineralisation is outcropped at the surface.
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Estimation and modelling techniques | - 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. sulphur 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.
| - The MRE is based on surface drilling and trenching results using Ordinary Kriging (OK) to inform 20 m x 20 m x 20 m blocks. The block model was constrained by wireframes modelled for the geological formations of the deposits and coded and domained by the level of oxidation and level of veining. The OK interpolation was carried out separately for each geological domain of each deposit. Hard boundaries were used between the interpreted geological domains. The drill hole and trench data were composited to a target length of 2 m based on the length analysis of raw intercepts. Top-cuts were estimated separately for gold and coper grades for each modelled domain and applied to sampled intervals before length compositing.
Interpolation parameters were as follows:
https://www.globenewswire.com/NewsRoom/AttachmentNg/455b3cf6-877a-4475-a45a-235c66863c46 - Previous JORC-compliant Mineral Resources were estimated by Mining Associates, and the estimate was available for review.
- No current mining is occurring at the Kharmagtai project.
- No by-products are assumed at this stage. Estimated molybdenum and silver grades appear to be sub-economic to extract at this stage of the project evaluation.
- Sulphur grades were interpolated into the models to establish their potential affect to metallurgical processing.
- The optimal parent cell size was selected in the course of block modelling. The linear parent cell dimensions along X- and Y-axes were 20 m x 20 m. The vertical parent cell dimension was 20 m. Block grades were interpolated using parent cell estimation. Nominal drill spacing was about 40 m x 40 m at the central parts of the deposits.
- It was assumed that a 20 m x 20 m x 20 m parent cell approximately reflects SMU for large scale open pit mining.
- No assumptions about correlation between variables were made.
- Geological interpretation was based on the results of detailed geological logging, which resulted in the development of wireframe models for all major geological formations for each deposit, which control copper and gold mineralisation (country rocks, porphyry phases, barren dyke. Logging of the level of veining and level of oxidation was used to develop wireframe models for the stockwork development (<0.5% veining, 0.5-1.5% veining and >1.5% veining) and also for breccia pipe and surface for the base of oxidation surface. The wireframe models for stockwork, breccia and oxidation were used to sub-domain the main geological formations of each deposit. All wireframe models were developed by Xanadu geologists using Leapfrog software.
- Top-cutting was applied separately for each geological domain and sub-domain based on the results of the classical statistical analysis.
- Grade estimation was validated using visual inspection of interpolated block grades vs. sample data, alternative interpolation methods and swath plots.
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Moisture | - Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content.
| - Moisture was not considered in the density assignment and all tonnage estimates are based on dry tonnes.
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Cut-off parameters | - The basis of the adopted cut-off grade(s) or quality parameters applied.
| - A cut-off grade of 0.3% CuEq was used to report the Mineral Resources for open pit mining within the limits of ultimate undiscounted pit shell, and a cut-off of 0.5% CuEq was used to report the Mineral Resources for underground mining below the ultimate undiscounted pit shell.
The copper equivalent (eCu) calculation represents the total metal value for each metal, multiplied by the conversion factor, summed and expressed in equivalent copper percentage with a metallurgical recovery factor applied.
Copper equivalent (CuEq) grade values were calculated using the following formula:
CuEq = Cu + Au * 0.62097 * 0.8235,
Where:
Cu - copper grade (%)
Au - gold grade (g/t)
0.62097- conversion factor (gold to copper)
0.8235 - relative recovery of gold to copper (82.35%)
The copper equivalent formula was based on the following parameters (prices are in USD):
- Copper price - 3.1 $/lb (or 6834 $/t)
- Gold price - 1320 $/oz
- Copper recovery - 85%
- Gold recovery - 70%
Relative recovery of gold to copper = 70% / 85% = 82.35%. |
Mining factors or assumptions | - 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.
| - No mining factors have been applied to the in-situ grade estimates for mining dilution or loss as a result of the grade control or mining process. The deposit is amenable to large scale bulk mining. The Mineral Resource is reported above and outside of an optimised ultimate pit shell (Lerch Grossman algorithm), mineralisation below the pit shell is reported at a higher cut-off to reflect the increased costs associated with block cave underground mining.
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Metallurgical factors or assumptions | - 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.
| - No metallurgical factors have been applied to the in-situ grade estimates. Metallurgical recoveries were used when copper equivalent grades were calculated in the model. The applied recoveries were 85% for copper and 70% for gold. Relative gold to copper recovery was 82%.
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Environmental factors or assumptions | - 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.
| - An environmental baseline study was completed in 2003 by Eco Trade Co. Ltd. of Mongolia in cooperation with Sustainability Pty Ltd of Australia. The baseline study report was produced to meet the requirements for screening under the Mongolian Environmental Impact Assessment (EIA) Procedures administered by the Mongolian Ministry for Nature and Environment (MNE).
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Bulk density | - 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.
| - A total of 4428 measurements for bulk density are recorded in the database, all of which were determined by the water immersion method.
- The average density of all samples is approximately 2.75 t/m3. In detail there are some differences in density between different rock types. Therefore, since the model includes all major geological domains, density values were applied separately for each domain:
https://www.globenewswire.com/NewsRoom/AttachmentNg/f544cea4-b181-45bb-b39d-9332609a8132
- Average bulk density values were applied for each geological domain, though there could be variations in density values due to presence of sulphides or level of alteration.
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Classification | - 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.
| - The Mineral Resource has been classified based on the guidelines specified in the JORC Code. The classification level is based upon an assessment of geological understanding of the deposit, geological and mineralization continuity, drill hole spacing, QC results, search and interpolation parameters and an analysis of available density information.
The following approach was adopted:
° Measured Resources: Not reported. ° Indicated Resources: It was decided that Indicated Mineral Resources be assigned to blocks which were explored with the drill density not exceeding approximately 65 m x 65 m with at least two mineralization intersections on exploration lines. Geological structures are relatively well understood and interpreted. ° Inferred Resources: Inferred Mineral Resources are model blocks lying outside the Indicated wireframes, which still display reasonable strike continuity and down dip extension, based on the current drill hole and trench intersections. - Data quality, grade continuity, structural continuity and drill spacing were assessed by CSA Global to form an opinion regarding resource confidence.
- The classification reflects the Competent Person’s view of the deposit.
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Audits or reviews | - The results of any audits or reviews of Mineral Resource estimates.
| - The Mineral Resource block model was peer reviewed internally by a Principal Resource Geologist employed by CSA Global and the conclusion was made that the procedures used to estimate and classify the Mineral Resource are appropriate.
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Discussion of relative accuracy/ confidence | - 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.
| - Industry standard modelling techniques were used, including but not limited to:
– Classical statistical analysis, – Interpretation and wireframing of main geological formations, – Top-cutting and interval compositing, – Domaining of the model using level of logging veining, breccia and zone of oxidation, – Geostatistical analysis, – Block modelling and grade interpolation techniques, – Model classification, validation and reporting,
The relative accuracy of the estimate is reflected in the classification of the deposit. - The estimate is related to the global estimate of the deposit suitable for subsequent PFS or further exploration at the deposit.
- No historical production data is available for comparison with the MRE.
- The Mineral Resource accuracy is communicated through the classification assigned to various parts of the deposit.
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