JORC Code explanation

Commentary

Sampling techniques

• Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling.
• Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used.
• Aspects of the determination of mineralisation that are Material to the Public Report.

• Samples from the diamond-core holes are being taken from mostly HQ3 and NQ3 sized core and sampled on a nominal 1 metre basis taking into account smaller sample intervals up to geological contacts. The core is cut in half along the core orientation line (where available) and in massive sulphide zones one portion is quartered for assaying, half the core is preserved for metallurgical testing and the remaining quarter is retained as reference material in the core trays. In non-massive sulphide material half core is sampled.
• These sampling methods are standard industry methods and are believed to provide acceptably representative samples for the type of mineralisation encountered.

Drilling techniques

• Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details.

• Diamond-core drilling is being undertaken by Sandvik UDR650 rigs with HQ3 and NQ3 sized core being drilled. Various techniques are employed to ensure the hole is kept within limits of the planned position. The core is laid out in standard plastic cores trays.

Drill sample recovery

• Method of recording and assessing core and chip sample recoveries and results assessed.

• The core is transported to an enclosed core logging area and recoveries are recorded. Recoveries to date have been better than 95%. The core is orientated where possible and marked with 1 metre downhole intervals for logging and sampling.

Logging

• Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies.

• The diamond core is geologically logged by qualified geologists. Geotechnical logging is also being undertaken on selected sections of the core Samples for metallurgical testing are being kept in a freezer to reduce oxidation prior to being transported to the metallurgical laboratory.

Sub-sampling techniques and sample preparation

• For all sample types, the nature, quality and appropriateness of the sample preparation technique.

• All core samples are crushed then pulverised in a ring pulveriser (LM5) to a nominal 90% passing 75 micron. An approximately 250g pulp sub-sample is taken from the large sample and residual material stored.
• A quartz flush (approximately 0.5 kilogram of white, medium-grained sand) is put through the LM5 pulveriser prior to each new batch of samples. A number of quartz flushes are also put through the pulveriser after each massive sulphide sample to ensure the bowl is clean prior to the next sample being processed. A selection of this pulverised quartz flush material is then analysed and reported by the lab to gauge the potential level of contamination that may be carried through from one sample to the next.

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.
• 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.

• Sample preparation and assaying is being conducted through ALS Laboratories, Orange, NSW with certain final analysis of pulps being undertaken at the ALS Laboratory in Brisbane QLD.
• Gold is determined by 30g fire assay fusion with ICP-AES analysis to 1ppb LLD.
• Other elements by mixed acid digestion followed by ICP-AES analysis. 
• Laboratory quality control standards (blanks, standards and duplicates) are inserted at a rate of 5 per 35 samples for ICP work.

Verification of sampling and assaying

• The verification of significant intersections by either independent or alternative company personnel.
• Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols.
• Discuss any adjustment to assay data.

• An internal review of results was undertaken by company personnel. No independent verification was undertaken at this stage.
• All field and laboratory data has been entered into an industry standard database using a contract database administrator (DBA) in the Company’s Perth office. Validation of both the field and laboratory data is undertaken prior to final acceptance and reporting of the data.
• Quality control samples from both the Company and the Laboratory are assessed by the DBA and reported to the Company geologists for verification. All assay data must pass this data verification and quality control process before being reported.

Location of data points

• Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation.

• The drill collars were initially located with a combination of handheld GPS and licenced surveyor using a DGPS system, with accuracy of about 1m. The final drill collars are “picked up” by a licenced surveyor with accuracy to 1 centimetre.
• While drilling is being undertaken, downhole surveys are conducted using a downhole survey tool that records the magnetic azimuth and dip of the hole. These recordings are taken approximately every 30 metres downhole. Where possible holes are also being surveyed with gyroscopic methods, with some 80 percent of holes drilled in the current program also surveyed by this method after drilling has been completed.

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 continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied.
• Whether sample compositing has been applied.

• The diamond drilling is mostly following-up in various directions from previous intercepts with a nominal spacing in the range 30-40m. This drill hole spacing will be sufficient to provide Mineral Resource estimates in the future.

Orientation of data in relation to geological structure

• Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type.

• The drilling orientation is designed to intersect the mineralised lenses at a close to perpendicular angle. The mineralised lenses are dipping at approximately 50-70 degrees to the west and the drilling is approximately at 60 degrees to the east. This will vary from hole to hole.

Sample security

• The measures taken to ensure sample security.

• Samples are being secured in green plastic bags and are being transported to the ALS laboratory in Orange, NSW via a courier service or with Company personnel/contractors. 

Audits or reviews

• The results of any audits or reviews of sampling techniques and data.

• A review and assessment of the laboratory procedures was under taken by company personnel in late 2014 resulting in some changes to their sample pulverising procedure.

JORC Code explanation

Commentary

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 Woodlawn project is located 250km south-west of Sydney in the state of New South Wales. The area is near the top of the Great Australian Dividing range and has an elevation around 800m above sea-level. The mineral and mining rights to the project are owned 100% by the Company through the granted, special mining lease 20 (SML20). The lease has been renewed to the 16 November 2029.
• The project area is on private land owned by Veolia who operate a waste disposal facility that utilises the historical open-pit void. An agreement is in place with Veolia for the Company to purchase certain sections of this private land to facilitate future mining and processing activities. A cooperation agreement is also in place between Veolia and the Company that covers drilling and other exploration activities in the area.

Exploration done by other parties

• Acknowledgment and appraisal of exploration by other parties.

• The Woodlawn deposit was discovered by the Jododex JV in 1970 and open-pit mining began in 1978 and continued through to 1987. The project was bought outright by Rio Tinto Ltd (CRA) in 1984 who completed the open-pit mining. Underground operations commenced in 1986 and the project was sold to Denehurst Ltd in 1987 who continued underground mining up until 1998. The mineral rights to the project were then acquired by TriAusMin Ltd in 1999 who conducted studies on a tailings re-treatment process and further underground operations. Heron took 100% ownership of the project in August 2014 following the merger of the two companies. Some 980 surface and underground drill holes have been completed on the project to date and various studies undertaken.

Geology

• Deposit type, geological setting and style of mineralization.

• The Woodlawn deposit comprises volcanogenic massive sulphide mineralisation consisting of stratabound lenses of pyrite, sphalerite, galena and chalcopyrite. The mineralisation is hosted in the Silurian aged Woodlawn Felsic Volcanic package of the Goulburn sub-basin on the eastern side of the Lachlan Fold Belt.

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:

• A table detailing the drill hole information is given in the body of the report.

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 reported assays are weighted for their assay interval width. The majority of the assay interval widths are 1 metre, but this weighting does take into account the non 1 metre intervals and weights the average assay results accordingly.
• For the results reported here no weighting was included for specific gravity (SG) measurements that have been taken for all sample intervals as the samples within the intervals are of a similar SG.

Relationship between mineralization 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.

• The massive sulphide zone intercepted in the drilling to date is at an angle to the drill axis and therefore the true width is estimated to be some 0.8 of down-hole width. That is, a down-hole intercept of 16m equates to a true width of 12m. This is only an approximation at this stage and will be better estimated as the orientation of the lenses is better defined.

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.

• A long-section showing the hole positions relevant for current phase of exploration is included in the release. Other maps and diagrams showing the location of the Woodlawn Project are included in other recent Company releases.

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.

• The reporting is considered to be balanced and all relevant results have been disclosed for this current phase of exploration.

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.

• The drill holes are being cased with either 40 or 50 millimetre PVC tubing for down-hole DHEM surveying which is undertaken on the majority of the holes drilled.
• Geotechnical logging is undertaken on all core, 25m either side of the massive sulphide lenses.
• Archimedes method SG measurements are determined for all sampled intervals.

Further work

• The nature and scale of planned further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling).

• This report is the first report for the second phase of diamond drilling at Woodlawn. The program is designed to provide the critical drill data for the Mineral Resource definition that will feed into the Feasibility y Study now underway.
• It is expected that this program will be ongoing over the next 6 to 8 months.