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Microsoft Word - 20151020 WRP Resource Statment Final 2
Heron Resources Limited
ASX/TSX Release
20 October 2015
Level 1, 37 Ord Street, West Perth WA 6005 [email protected]
+61 8 6500 9200
ABN: 30 068 263 098
ASX:HRR/TSX:HER
Issued Shares 415M Share Price $0.099
Market Cap $41M Cash (31 Aug 2015) $28.2M
Investments $ 2.8M
Total C+I $31.0M
Heron confirms 10Mt (M+I) of High Grade Tailings at 6.2% ZnEq1 within Revised JORC 2012 Mineral Resource Estimate
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Woodlawn Tailings JORC 2012 Mineral Resource estimate summary:
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Incorporates additional 2008 and 2011 drilling - Mineral Resource now based on 332 holes for 2,683 metres
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4.6% increase in Measured and Indicated Mineral Resources tonnages
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6.1% lower overall tonnages than previous estimate due principally to more conservative density estimates
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Metal grades similar to previous estimates and have confirmed the high grade content of this material
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Mine planning for a revised Mineral Reserve has commenced and together with the underground project will form the basis of the production plan for the ongoing Woodlawn Feasibility Study
Heron Resources Limited (ASX:HRR TSX:HER, 'Heron' or the 'Company') is pleased to provide an updated estimate of the Woodlawn Tailings Retreatment Project (WRP) Mineral Resource at its wholly owned Woodlawn Project, located 250km south-west of Sydney, New South Wales, Australia. The previous estimate which dated from 2008 has been revised to incorporate additional drilling between 2008 and 2011. The estimate methodology and reporting is based on the requirements of the JORC 2012 Code.
The update to the WRP Resource is an integral part of the ongoing Woodlawn Feasibility Study with this work providing key input data for the tailings retreatment component of the project. The upgrade of the Mineral Resource to JORC 2012 required a comprehensive review of previous work and also allowed for the inclusion of drilling data that had been completed after the previous estimate. This detailed review, and the inclusion of the additional data, further improves the confidence in the reported estimates and will provide the basis for a new mining study and updated Mineral Reserve estimate.
The WRP is based around the re-processing of the tailings generated from the Woodlawn open-pit and underground mining operations that ran from 1978 to 1998. The tailings are contained in three tailings dams; Tailings Dam North (TDN), Tailings Dam South (TDS) and Tailings Dam West (TDW), see Figures 1-3. A proportion of TDN was previously re-treated with these re-treated tailings placed back into the same dam. These retreated tailings are estimated separately and designated 'North_R' in the tables below.
A number of drill programs have been undertaken over the years, with the estimate utilising a total of 332 drill holes (distribution shown in Figure 3) and 1,312 samples. Drilling was mostly undertaken by Vibracore and push core drilling
1 Zn equivalents (ZnEq) in this release are based on the formula: Zn(%) + 0.81 x Pb(%) + 3.12 x Cu(%) + 0.86 x Au(g/t) + 0.03 x Ag(g/t). Metal prices used in the calculation are: Zn US$2,300/t, Pb US$ 2,050/t, Cu US$6,600/t, Au US$1,250/oz and Ag US$18/oz. All these metals are expected to be recoverable. Refer to p15 of the announcement of 22 April 2015 entitled 'Preliminary Economic Assessment Delivers Strong Business Case for the Woodlawn Zinc-Copper Project' for further information.
rigs. Samples were taken in approximately 1-2 metre intervals down the holes. Parts of the dams have been covered in water and remain undrilled and such areas account for the majority of the Inferred Mineral Resources category (Figure 3).
Drill samples were analysed at commercial Australian laboratories and industry standard methods were employed. The estimation was undertaken utilising a mining software package with grade distribution based on kriged or inverse-distance interpolations. No cut-off grades have been applied to the estimate as there is gross uniformity to the grades and no selective mining is envisaged. The available historic records of tailings placed into the dams (totalling 10.95Mt) reconciles to within approximately 1% of the total tonnages contained within the updated Mineral Resource Estimate.
Measured and Indicated Mineral Resource categories were based on drill hole spacing, while Inferred Mineral Resources occupy areas under water or where sparse drilling is present. Mining factors were taken into account when selecting the block size for the estimate; the estimate is based on 10m x 10m x 1m block sizes that have subsequently converted to 10m x 10m x 5m for mine scheduling and reserve reporting. The mining of the tailings is expected to proceed using hydraulic mining methods on 5 to 10m benches.
Further details can be found in the JORC (2012) Table 1 at the end of the report. The following tables provide various breakdowns of the Mineral Resource estimate. By Dam:
By Mineral Resource Category:
Figure 1: Aerial View of the Woodlawn Project area showing the Tailings Dams; the subject of this Mineral Resource estimate.
Figure 2: Oblique plan view of the tailings dams showing the Mineral Resource blocks colour coded by ZnEq%
Figure 3: Plan view of the tailings dams showing the Mineral Resource blocks colour coded by resource category and drill collars
Forward Program
The revision of the Mineral Resource estimate for the WRP is an important component of the Feasibility Study, due for completion in June 2016, for the combined development of the tailings and underground mining operations. The revised estimate incorporates a substantial amount of new drilling data and provides a more robust estimate for planning work.
The block model for the estimate is now being optimised for mining and process scheduling which will also generate the Mineral Reserve base for the Feasibility Study.
A program of further drilling is being planned on the tailings dams as part of the Feasibility Study to provide additional material for metallurgical and paste-fill testwork.
The completed Technical Report in standard form prescribed by Canadian National Instrument 43-101 Standards of Disclosure for Mineral Projects will be published on Heron's web site, the ASX (ASX:HRR) and SEDAR www.sedar.com (TSX:HER) within 45 days of this news release. The Mineral Resource was classified into Measured, Indicated or Inferred categories in accordance with the guidelines of the 2012 edition of the JORC Code. It should be noted that there are no material differences between the Mineral Resource categories reported herein whether using those defined by JORC (2012) or the CIM Definition Standards on Mineral Resources and Reserves (CIM Definition Standards) adopted by CIM Council on May 10, 2014. The Mineral Resource, Mineral Reserve, and Mining Study definitions as described in the CIM Definition Standards are incorporated, by reference, into National Instrument 43-101 - Standards of Disclosure for Mineral Projects (NI 43-101).
About Heron Resources Limited:
Heron is engaged in the exploration and development of base and precious metal deposits in Australia. Heron's primary development project is the high grade Woodlawn Zinc-Copper Project located 250km southwest of Sydney, Australia.
Mr Wayne Taylor, Mr Jon Snowball
Managing Director and Chief Executive Officer: FTI Consulting
Tel: +61 8 6500 9200 Tel: +61 2 8298 6100 or +61 477 946 068
Email: [email protected] Email: [email protected]
Canada:
Tel: +1 905 727 8688 (Toronto)
Compliance Statement (JORC 2012 and NI43-101)
The Woodlawn Tailings Mineral Resource estimate contained in this release has been completed and compiled by Mr Robin Rankin, a Competent Person who is a Member (No. 110551) of the Australasian Institute of Mining and Metallurgy (AusIMM) and accredited by the AusIMM since 2000 as a Chartered Professional (CP) in the geology discipline. Mr Rankin consults to Heron as Principal Consulting Geologist of independent geological consultancy GeoRes. He and GeoRes are professionally and financially independent of Heron, the consulting was on a fee basis and results were not contingent on payments. He has sufficient experience, which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined in the JORC Code (2012 edition) and 'qualified person' as this term is defined in Canadian National Instrument 43-101. Mr Rankin consents to the inclusion in this release of the matters based on his information in the form and context in which it appears.
CAUTIONARY NOTE REGARDING FORWARD-LOOKING INFORMATION
This news release contains forward-looking statements and forward-looking information within the meaning of applicable Canadian securities laws, which are based on expectations, estimates and projections as of the date of this news release. This forward-looking information includes, or may be based upon, without limitation, estimates, forecasts and statements as to management's expectations with respect to, among other things, the timing and amount of funding required to execute the Company's exploration, development and business plans, capital and exploration expenditures, the effect on the Company of any changes to existing legislation or policy, government regulation of mining operations, the length of time required to obtain permits, certifications and approvals, the success of exploration, development and mining activities, the geology of the Company's properties, environmental risks, the availability of labour, the focus of the Company in the future, demand and market outlook for precious metals and the prices thereof, progress in development of mineral properties, the Company's ability to raise funding privately or on a public market in the future, the Company's future growth, results of operations, performance, and business prospects and opportunities. Wherever possible, words such as 'anticipate', 'believe', 'expect', 'intend', 'may' and similar expressions have been used to identify such forward-looking information. Forward-looking information is based on the opinions and estimates of management at the date the information is given, and on information available to management at such time. Forward-looking information involves significant risks, uncertainties, assumptions and other factors that could cause actual results, performance or achievements to differ materially from the results discussed or implied in the forward-looking information. These factors, including, but not limited to, fluctuations in currency markets, fluctuations in commodity prices, the ability of the Company to access sufficient capital on favourable terms or at all, changes in national and local government legislation, taxation, controls, regulations, political or economic developments in Canada, Australia or other countries in which the Company does business or may carry on business in the future, operational or technical difficulties in connection with exploration or development activities, employee relations, the speculative nature of mineral exploration and development, obtaining necessary licenses and permits, diminishing quantities and grades of mineral reserves, contests over title to properties, especially title to undeveloped properties, the inherent risks involved in the exploration and development of mineral properties, the uncertainties involved in interpreting drill results and other geological data, environmental hazards, industrial accidents, unusual or unexpected formations, pressures, cave- ins and flooding, limitations of insurance coverage and the possibility of project cost overruns or unanticipated costs and expenses, and should be considered carefully. Many of these uncertainties and contingencies can affect the Company's actual results and could cause actual results to differ materially from those expressed or implied in any forward-looking statements made by, or on behalf of, the Company. Prospective investors should not place undue reliance on any forward-looking information. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions, the Company cannot assure prospective purchasers that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither the Company nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. The Company does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward- looking information contained herein to reflect new events or circumstances, except as may be required by law.
No stock exchange, regulation services provider, securities commission or other regulatory authority has approved or disapproved the information contained in this news release.
JORC CODE, 2012 EDITION - TABLE 1
Information in Section 1 (sampling and data) of the Table was derived from reports or data provided by Heron. Robin Rankin (the 'Consultant' or 'GeoRes') provided or produced all other details.
The Consultant was engaged to undertake a Mineral Resource update based on his previous work reported in May 2008, with the essential difference being the incorporation of additional drilling data - effectively 'in-fill' drilling. As such, most data and processing details were the same as for the previous work, and many details included here originated from the Consultant's previous Mineral Resource estimation and reporting work on the WRP. It should be noted that the May 2008 Mineral Resource estimates were reported under the 2004 JORC Code and so a JORC Table 1 under the 2012 Edition of the Code was not provided.
SECTION 1 SAMPLING TECHNIQUES AND DATA
Details in Section 1 apply to the 'new' drilling data (acquired during or since 2008 and used for this 2015 Resource estimate update) as well as the pre-2008 data used in the estimation reported in May 2008. This new data approximately doubled the size of the data set. Both data sets are similar in most details.
(Criteria in this section apply to all succeeding sections.)
Criteria JORC Code explanation Commentary
Sampling techniques
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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 down hole gamma sondes, or handheld XRF instruments, etc.). These examples should not be taken as limiting the broad meaning of sampling.
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Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used.
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Aspects of the determination of mineralisation that are Material to the Public Report.
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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.
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Historical:
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Sampling:
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Source: All from short vertical drill holes. Drilled in several programs and with several methods specifically adapted to drilling and sampling semi-loose saturated tailings dam material.
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Sampling: Specifics varied according to drilling method. But sampling undertaken on full hole lengths with short down-hole sample intervals for representivity and as dictated by drilling method (tube lengths etc.).
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Quality: Specifics unknown in terms of duplicates or contamination, but complete intervals sampled and then split down. Comparisons good between adjacent holes and different programs.
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Elements: Assayed for base metals and related elements.
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Further details on sampling and assaying techniques provided in sections below.
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Sampling representivity:
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Sample representivity is considered to be good overall.
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Samples taken of whole drill lengths, split by down-hole sub- sampling.
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Most drill holes sampled to full dam depth.
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Hole distribution fairly uniform over the majority of dam areas.
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Sample lengths variable between drilling methods, but short enough to be representative.
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Sampling based on short fixed down-hole intervals.
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All samples of very similar granular to fine sized material.
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Mineralisation identification:
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Determination of mineralisation unnecessary due to detailed knowledge of neighbouring source mine material and subsequent processing before deposition in tailings dams.
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Consistent sampling for base metals.
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Mineralisation presumed throughout full dam volumes - only grade varying with original processing efficiency.
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Industry standard:
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Criteria
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JORC Code explanation
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Commentary
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o No general industry standard work assumed as sampling of tailings dams relatively unusual and requiring methods partly requiring adaptation to actual local conditions.
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Drilling techniques
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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.).
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Drilling methods:
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Different programs used different drilling methods:
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Core - 1988 & 1995, Denehurst
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Auger - prior to 2009, TRO
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Vibracore - 2008 & 2011, TRO
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Core: 50 mm stainless steel tube, with sample catchers at every 2 m rod break. Tubes pushed down into tailings.
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Auger: 75 mm auger. Sampling on 3 m intervals. Depths mostly 3 m.
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Vibracore: Proprietary method. 50 mm tube. Depth 2.7 to 18
Depths ~5-14 m.
m. Double tube method, samples recovered from inner tube. Samples in 1.5 m plastic tubes.
o Survey: Down-hole surveys presumed unnecessary from short nature of the vertical holes.
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Drill sample recovery
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Method of recording and assessing core and chip sample recoveries and results assessed.
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Measures taken to maximise sample recovery and ensure representative nature of the samples.
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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.
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Logging
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Whether core and chip samples Logging adequacy:
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Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc.) photography.
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The total length and percentage of the relevant intersections logged.
have been geologically and o Geological logging not necessary as samples were not of
geotechnically logged to a level primarygeology.
of detail to support appropriate o Assays and sample details alone taken to be sufficient data.
Mineral Resource estimation,
mining studies and metallurgical studies.
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Sub-sampling techniques and sample preparation
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If core, whether cut or sawn and The following is derived from an internal report supplied by Heron.
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If non-core, whether riffled, tube The samples were obtained by driving a 50mm stainless steel tube column sampled, rotary split, etc. and through the tailings. Each tube was 2m long and lengths were joined by a whether sampled wet or dry. threaded stainless steel coupling. A stainless steel cutting bit was attached
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For all sample types, the
whether quarter, half or all core
taken. 1.0 Denehurst Core (1988)
nature, quality and to the first length. Venus flytrap type catches were positioned at each joint
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Criteria JORC Code explanation Commentary
appropriateness of the sample preparation technique.
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Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples.
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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.
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Whether sample sizes are appropriate to the grain size of the material being sampled.
to enable core recovery. The column was driven through the tailings by a pulley mounted 15kg weight. This was supported by a 3m apex high quadrapod on a 3m square platform. The platform was mounted on drums to enable samples to be obtained from holes covered by water. The core column was retrieved via a winch arrangement.'
Measurements of recovered core length and total depth were taken to calculate compaction. The sample was retrieved from the pipe lengths by ramming a disc down the tube and laying the core in halved poly pipes. Sections were then collected, typically 1.5-2.5m long and placed in plastic buckets. The length of sections was dependent on the total length recovered. Sample intervals for assay ranged from 0.4m to 3.4m. The average and median sample length was approximately 2.2m.
Samples from the buckets were then thoroughly mixed using a spade on a clean concrete surface. A representative sample was collected by quartering, and then placed in an oven. Wet and dry weights were taken to calculate the moisture content. Excess sample was bagged and stored.
The dried samples were split for sizing and assay. Samples for assay were pulverised and then analysed by XRF for Cu, Pb, Zn, Fe and Ag. Non sulphide Pb and Zn determinations were made by Ammonium Acetate solubility. Gold assays, where required, were by fire assay. Size fraction assays were performed to indicate the distribution of metal values by size. Where sample wasn't sufficient for assay by XRF, AAS was used. All work was undertaken by Woodlawn technical staff and assaying was performed in the onsite laboratory.
2.0 Denehurst Core (1995)
A company known as Coastline Drilling from Queensland were contracted for this program. 'The drilling was conducted in May 1995. Only 15 holes of a planned 19 holes were drilled due to access difficulties. The drilling programme was overseen by the Senior Geologist, Mark Bouffler. Sampling for assays and metallurgical testwork was conducted by Woodlawn laboratory technical staff'. Coastline drilled 15 holes on TDS ranging in depth from 5-14m. The holes were 50mm in diameter. The drilling method used was very similar to the vibratory core method (see 4.0 below).
Samples for assay were collected at 1m intervals and analysis was performed at the Woodlawn NATA registered laboratory using AAS for Cu, Pb, Zn, Ag, and XRF for Fe, Si and Mg.
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Tri Origin Auger Drilling:
Auger drilling was carried utilising a power auger rig mounted on a Toyota Land Cruiser. Auger holes were 75mm in diameter. Sampling was undertaken on nominal 3m intervals with most of the auger holes drilled to only 3m. The drilled tailings were regularly collected from around the hole collar as it returned up the auger flight. Systematic grab samples were gathered and placed into a calico bag for dispatch to the laboratory. The calico samples typically weighed around 2-4kg. The reject sample was placed into a bucket for storage. Grab sampling has been shown to be a reliable sub-sampling technique primarily due to the fine grained and homogenous nature of the tailings material. Orientation sampling results also support this assertion.
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Criteria
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JORC Code explanation
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Commentary
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Sample recoveries were estimated by measuring the weight of the sample and comparing that to the expected weight extracted from the drilled run, based on volume and average wet densities. This indicated that all samples had greater than 90% recovery.
4.0 Tri Origin/TriAusMin Core
Core Drilling was carried out with a Geoprobe 6620DT rig utilising the Vibracore method. All three Vibracore programs utilised the same contractor, (Numac Drilling), the same drill rigs and drilling equipment. The hole diameter was 50mm. Hole depths ranged from around 2.7m to 18.0m. The Vibracore rig was found to be an ideal machine for drilling the tailings, due to the low load bearing capacity of the rig, quality of sample achieved and excellent productivity.
Geoprobe® brand utilise 'Dual Tube Sampling Systems'. This is a very efficient method for collecting continuous 'soft cores' with the added benefit of a cased hole. Dual tube sampling uses two sets of probe rods to collect continuous core. The method is similar to wire-line diamond core drilling. However, as opposed to rod rotation, the outer rod string is vibrated by rapid hammering. The drilled sample reports to a 1.5m long PVC tube housed in a 1.5m long 'sample rod'. The sample rod string is recovered through the outer rod/casing string which remains in the ground until hole completion.
5.0 Tri Origin/TriAusMin Sampling
Sampling intervals were a composite of two drill runs until the end of the hole is reached. So the first sample from 0 - 2.7m was comprised of the 0 - 1.5m and the 1.5 - 2.7m sample combined. The starter rod sample was 1.5m. Sampling after this was conducted on 2.4m intervals (2 x 1.2m) until the end of the hole is reached.
After the PVC tube is extracted from the sample rod, the tube is split (with a cutter). The exposed tailings core remains in the PVC which is placed on a hard surface. A nominal ½ core sample is cut and then bagged for dispatch to the assay laboratory. This process is nominally performed twice to produce one composite sample (until the end of hole sample). The reject sample is 'extruded' from the cut tube into a large plastic bucket and a sealed lid is placed on.) The bucket sample and calico sample (placed on top of the lid) are then weighed.
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Quality of assay data and laboratory tests
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TriAusMin and TriOrigin to 2009
Samples were analysed by ALS Chemex.
All samples were weighed upon receival and dried for 24 hours, the whole sample was then pulverised to 80% passing 75 microns. Assay charges were then extracted from a 100g pulp. The pulp was placed in kraft packet and the remaining pulverised bulk residue placed back into the original calico bag. A combination of ICPAES and fire assay
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The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total.
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For geophysical tools, spectrometers, handheld XRF instruments, etc., the parameters used in determining the analysis including
Criteria JORC Code explanation Commentary
instrument make and model, reading times, calibrations factors applied and their derivation, etc.
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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.
for gold were utilised. All methods can be considered as total extraction for the analytes requested.
QAQC Procedures
Standards
Certified Reference Materials or standards were used as part of the company policy to monitor the accuracy of the laboratory. The following standards were inserted at the designated frequency;
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Au standard - every 20 samples (not used in July 08 program)
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Base Metal standard - every 10 to 20 samples (alternating between a high and low grade base metal standards).
Field duplicates
Field duplicates in the form of 1/2 or 1/4 were collected approximately every 20 samples. Results allow the precision of the sampling and analytical methods to be monitored.
Blanks
A certified blank sample was inserted approximately 20 samples. This assisted in monitoring lab procedures and assessing for sample contamination.
Analysis of the QA-QC data indicates that acceptable levels of accuracy and precision were obtained during all programs.
Historical Sample Assay Analysis (to 1998):
The documentation available to Heron indicates that the Jododex and AMS assay analysis included:
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Acid digestion of a pulversied aliquot and determination of copper, lead and zinc by AAS.
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Compressing a pulverized aliquot into a button for XRD analysis for copper, lead and zinc, as well as determining precious metals together with iron, silicon, aluminum, magnesium and barium.
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Fire assay of any gold values that exceeded 2ppm.
NATA registered laboratory on site at Woodlawn. Samples were analysed by:
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Aqua regia hydrofluoric and perchloric acid digest with AAS or ICP determination of Cu, Pb, Zn, Ag and Au.
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Gold assay reporting above 2ppm were re-assayed by fire assay.
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For some samples, a second aliquot was analysed by pressed powder XRF to determine Fe, Mg, Si, Al and Ba grades.
Historical QAQC Methods (to 1998):
At the time of the historical drilling and mining, blind QAQC samples were not routinely included in sample submissions to the laboratory. No QAQC data have been located for this period.
The NATA certified onsite laboratory carried out internal QC, which included the insertion of certified reference standards and duplicates on a sample batch basis. No historical hardcopy data could be sourced for validation of QC, although resource reviews at the time
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Criteria
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JORC Code explanation Commentary
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indicate that internal QC was a routine part of the laboratory assay process. Furthermore, the laboratory was required to perform such analyses as part of its ongoing NATA accreditation. This included independent QC testing by independent laboratories, as well as the onsite laboratory being employed to provide umpire assays of other laboratories.
o Not necessary and none undertaken.
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Verification of sampling and assaying
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The verification of significant Independent verification of significant intersections:
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The use of twinned holes.
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Documentation of primary data, o A significant number of holes were twinned.
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Discuss any adjustment to o No information on data entry or storage.
intersections by either o Nature of fairly homogenised tailings material meant assays
independent or alternative varied only slightly from hole to hole and by depth.
company personnel. Twinned holes:
data entry procedures, data o The Consultant is not aware of the details of any analysis.
verification, data storage Primary data documentation, entry, verification and storage:
(physical and electronic) o All data was historical and supplied in computerised spread-
protocols. sheet form.
assay data. Adjustment of assays:
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Location of data points
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Accuracy and quality of surveys Surveying:
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Specification of the grid system Some hole collars picked up by the Consultant during
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Quality and adequacy of Other (older?) collars now not visible as tailings dam
used to locate drill holes (collar o Collars:
and down-hole surveys), The specific accuracy of all the drill collar locations trenches, mine workings and has not been verified but are believed to be accurate other locations used in Mineral
Resource estimation. based on methods employed by the various programs.
used. site visits and found to be accurate.
topographic control. surface easily eroded by rainfall.
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Coordinate grid system:
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Topography:
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Surface topography highly accurate.
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Comparison of drill hole collars with topo locations logical.
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Hole collar elevations checked against topography and moved to topo elevation where obvious (others very close anyway).
All coordinates are in the Woodlawn Mine Grid system.
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Data spacing and distribution
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Data spacing for reporting of Data spacing:
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Whether the data spacing and (North Dam) or regular at 50 m on lines 100 m apart. distribution is sufficient to o 2008 collars generally in-fill at 50 m spacing. establish the degree of
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Whether sample compositing o Down-hole sampling was generally fine at ~1-2 m.
Exploration Results. o Pre 2008 hole collar spacing either random at 50-100 m
geological and grade continuity o Overall hole spacing all
appropriate for the Mineral adequate.
Resource and Ore Reserve o Hole spacing in the northern part of the South Dam ~30 m. estimationprocedure(s) and o Parts of South and West Dams not drilled because of standing classifications applied. water (and reflected in Resource classification).
has been applied. Data distribution adequacy wrt estimation:
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Criteria
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JORC Code explanation
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Commentary
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The Consultant's view is that all sampling density in plan and down-hole was more than adequate to accurately represent strong lateral grade continuity in the sub-horizontal depositional mode of tailings being discharged onto accreting tailings surfaces.
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All dams were sampled at roughly the same density.
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Compositing:
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Samples were composited on-the-fly (without altering raw samples) during geostatistical analysis and block grade estimation.
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All samples composited to exactly 1.0 m plus 50% residuals.
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Compositing was performed on a domain/lode basis (i.e. starting and ending at domain boundaries).
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Orientation of data in relation to geological structure
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Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type.
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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.
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Sample security
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o Unknown.
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Audits or reviews
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Audits of past drilling:
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Unknown.
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Assays have not been independently audited.
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Heron performed considerable database verification during its databasing work. This flagged various issues which were researched as far as possible against historical records.
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However assay tenor and locations are supported by results from varying drilling and sampling programs over time.
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