REG - Thor Mining PLC - Tungsten Resource Increase at Pilot Mountain <Origin Href="QuoteRef">THRL.L</Origin> - Part 3

Thor EnergyAnnouncement

22/05/2017 07:06

- Part 3: For the preceding part double click  ID:nRSV7378Fb 

                                                                                                                                                                                                                                                                                                                                                                                                                             
                                                          '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.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
 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,     Diamond drilled core was the drill method used for the 2011/2012 program. Tri-cone rotary drilling was used in the first 100 ft of holes with poor ground conditions.  The earlier 1970s drilling method is unknown, but based on sample intervals is believed to be diamond coring also.                                                                                                                                                                                                                                                                                                                                                                       
                                                          depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
 Drill sample recovery                                    ·    Method of recording and assessing core and chip sample recoveries and results assessed.·    Measures taken to maximise sample recovery and ensure representative     Sample recovery is recorded for each logged interval. The core recovery is acceptable.  Any relationship between core recovery and grade has not been investigated.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
                                                          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                                                  ·    Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining       The 15 drill holes from 2011/2012 have information for collar, survey, assay, lithology, geotech, weathering, structure, veining, and density. Older holes contain only collar survey and assay data. Geological logging data is based on full examination.                                                                                                                                                                                                                                                                                                                                                                                                     
                                                          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           ·    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  The 2012 samples were half core cut and weighed.  The core half with orientation markings was retained, the other half was submitted for analysis.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
                                                          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               ·    The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total.·    For geophysical Field standards and duplicates were submitted with the core 2012 samples. No material bias was detected in the standards. Duplicates samples showed good repeatability.Flex-It downhole survey measurements were validated in two holes using a Gyro survey tool and found to be consistent.Validation of the 1970s assay results was undertaken by twinning four of the older holes.The data quality for the estimation of WO3 is acceptable but further drill hole twinning is recommended to better determine the accuracy ofhistoric silver (Ag) and copper (Cu) data.                                                                                      
                                                          tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
                                                          factors applied and their derivation, etc.·    Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
                                                          acceptable levels of accuracy (ie lack of bias) and precision have been established.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
 Verification of sampling and assaying                    ·    The verification of significant intersections by either independent or alternative company personnel.·    The use of twinned holes.·    Documentation of primary     A 5% check of the database against laboratory certificates and geological logs was undertakenHistorical level plans and N-S cross sections of the resource detailing geology data and interpretation as well as assay results for drilling conducted by Union Carbide Corporation in the 1970s are available. They indicate a greater breadth of data collection and geological understanding than provided in the electronic database. The initial seven holes drilled by Black Fire Minerals in 2011/2012 were designed to verify a sample of the pre-existing drilling.The 2012 drilling is consistent with the 1970s data.                                  
                                                          data, data entry procedures, data verification, data storage (physical and electronic) protocols.·    Discuss any adjustment to assay data.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
 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      Hole collar co-ordinates are referenced to NAD 83 (zone 11N). Collar locations from 1970s were digitised from maps translated to NAD83. Any historic collars that could be located in addition to the 2011/2012 drilling were surveyed by differential GPS.The topography was based on 10 ft contours from the most recent USA topographic survey. The topographic surface was adjusted to the surveyed drill hole collars.                                                                                                                                                                                                                                     
                                                          estimation.·    Specification of the grid system used.·    Quality and adequacy of topographic control.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
 Data spacing and distribution                            ·    Data spacing for reporting of Exploration Results.·    Whether the data spacing and distribution is sufficient to establish the degree of geological and grade       Exploration results are not being reported. Drill holes are spaced roughly 30 feet apart on 100 foot spaced sections.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
                                                          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  ·    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 The Desert Scheelite deposit trends dominantly east-west and dips variably 70-80º.The majority of holes have been drilled vertically resulting in a shallow core to mineralisation angle. The first seven of the 2011/2012 holes were also drilled vertically to validate the earlier drilling. The remaining eight 2011/2012 holes were angled to increase the mineralisation intersection angle providing a more representative sample..                                                                                                                                                                                                                      
                                                          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                                          ·    The measures taken to ensure sample security.                                                                                                                        Chain of custody details for the 1970s drilling are unavailable.The chain of custody for the 2011/2012 drill samples was reviewed on site by the CP delegate and deemed to be adequate.                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
 Audits or reviews                                        ·    The results of any audits or reviews of sampling techniques and data.                                                                                                A 5% check of the database against laboratory certificates and geological logs was undertaken. The referential integrity of the database was confirmed prior to modelling the resource.At this stage of the project no other independent external audits have been undertaken                                                                                                                                                                                                                                                                                                                                                                                   
 
 
Audits or reviews 
 
·    The results of any audits or reviews of sampling techniques and data. 
 
A 5% check of the database against laboratory certificates and geological logs
was undertaken. The referential integrity of the database was confirmed prior
to modelling the resource.At this stage of the project no other independent
external audits have been undertaken 
 
 Mineral tenement and land tenure status                           ·    Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings.·    The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area.                                                                                                                                                                                                                                       The Pilot Mountain Project comprises 154 unpatented Mineral Claims over 12.9 km2 located on the eastern flank of Pilot Mountain, 250 km southeast of the city of Reno and 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        20km east of the town of Mina, in Nevada, USA.At the time of writing the tenements are 100% controlled by Black Fire Minerals Limited.                                    
 Exploration done by other parties                                 ·    Acknowledgment and appraisal of exploration by other parties.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   The Desert Scheelite deposit discovery date is not known. The deposit was drilled by Duval in the early 1970s and subsequently by the Union Carbide Corporation (UCC) in  
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        the late 1970s The program comprised 71 vertical holes which are assumed to be diamond core totalling approximately 14,600 m, on sections spaced at 50 -100 feet (~15 - 30 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        m), to depths as great as 300 m. The mineralisation was exposed by UCC in a small trial pit excavated in 1981 After acquiring the project in 2011 BFE completed a further 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        15 diamond core holes totalling 3,047 m.  This program included twinning, in-filling and angled holes which provided geological and statistical data verification,        
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        improved geological interpretation and enabled the estimation of resources and JORC-compliant reporting by Golder Associates, for BFE, in 2012.                           
 Geology                                                           ·    Deposit type, geological setting and style of mineralisation.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   The Desert Scheelite deposit consists of skarn and calc-silicate altered marble bodies developed principally within the dominantly carbonate upper member of the Triassic 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Luning Formation, and to a lesser degree in thinner carbonate beds within the dominantly metaclastic middle and lower members of the Luning Formation. Intrusion of a     
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        biotite quartz monzonite stock during the Cretaceous led to contact metamorphism of adjacent carbonate units to marble and pelitic clastic units to hornfels. Mineralised 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        skarn and calc-silicate altered rock was locally formed in marble and to a lesser extent in calcareous meta-clastics during the latter phases of emplacement of the stock. 
 Drill hole Information                                            ·    A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes:o easting and northing of the drill hole collaro elevation or RL (Reduced Level - elevation above sea level in metres) of the drill hole collaro dip and azimuth of the holeo down hole length and interception deptho hole length.·    If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case.  Exploration results are not being reported. Details of the drilling used to define the resources are included in the resource estimation documentation.                   
 Data aggregation methods                                          ·    In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (eg cutting of high grades) and cut-off grades are usually Material and should be stated.·    Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail.·    The assumptions used for any reporting of metal equivalent values should be clearly stated.                                                                                                 Exploration results are not being reported.                                                                                                                               
 Relationship between mineralisation widths and intercept lengths  ·    These relationships are particularly important in the reporting of Exploration Results.·    If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported.·    If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (eg 'down hole length, true width not known').                                                                                                                                                                                                                                                                             Exploration results are not being reported.                                                                                                                               
 Diagrams                                                          ·    Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views.                                                                                                                                                                                                                                                                                                                                                                                               Exploration results are not being reported.                                                                                                                               
 Balanced reporting                                                ·    Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results.                                                                                                                                                                                                                                                                                                                                                                                                                                       Exploration results are not being reported.                                                                                                                               
 Other substantive exploration data                                ·    Other exploration data, if meaningful and material, should be reported including (but not limited to): 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.                                                                                                                                                                                                                                                                           Exploration results are not being reported.                                                                                                                               
 Further work                                                      ·    The nature and scale of planned further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling).·    Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive.                                                                                                                                                                                                                                                                                                                      Exploration results are not being reported.                                                                                                                               
 
 
Further work 
 
·    The nature and scale of planned further work (eg tests for lateral
extensions or depth extensions or large-scale step-out drilling).·    Diagrams
clearly highlighting the areas of possible extensions, including the main
geological interpretations and future drilling areas, provided this
information is not commercially sensitive. 
 
Exploration results are not being reported. 
 
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