Announcement PDF ASX ANNOUNCEMENT ASX : CXO 12th October 2015 Drilling intercepts mineralised breccia zone at Yerelina Zinc Project HIGHLIGHTS  Diamond drilling has intersected a 9.8m wide mineralised breccia zone at Great Gladstone Prospect  Base metal sulphides observed in breccia and veining as sphalerite (zinc) along with galena (lead)  The mineralised zone is also mapped as a gossan outcrop at surface and occurs within a fault zone interpreted to be up to 1.5km long  The current Yerelina drilling program has now been completed as planned, with assays expected in 4‐6 weeks  50% of drilling costs will be funded by SA Government through the PACE discovery drilling initiative Diamond drilling has intersected a mineralised breccia zone over a 9.8m section at the Great Gladstone Prospect. Great Gladstone is located within Core Exploration Ltd’s (ASX:CXO) Yerelina Zinc Project which covers a total area of approximately 1,000km2 in northern South Australia. The 9.8m section of mineralised breccias and veining was intersected by diamond drill hole YRDH003 from a depth of 144m downhole. Base metal sulphide mineralisation was observed within an intense breccia zone. The breccia consists of rotated slate clasts in a predominantly siderite‐carbonate‐ quartz matrix with a polyphase banded breccia/vein overprinting of sphalerite and silica along with ribbons of galena mineralisation (Figures 1‐4). The mineralised zone intersected in YRDH003 is located down dip of outcropping mineralised gossans. Surface channel sampling of these gossans at Great Gladstone returned significant zinc, lead and silver assays (refer ASX Announcement 2nd June 2015). The gossans are interpreted as the mineralised surface expression of a fault zone thought to be up to 1.5km long (Figure 5). A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Figure 1. Diamond drill core from the 9.8m zone of intense brecciation with mineralisation and veining intersected by YRDH003 at Great Gladstone Prospect Next Steps Core’s diamond drilling program at Yerelina comprises a total of five angled diamond core holes totalling approximately 1037m at a number of prospects (Table 1). The drill core from these recently completed drillholes is currently being transported from site to Adelaide, where the core will be cut, sampled and submitted for laboratory assay. Assay results are expected in approximately 4‐6 weeks. A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Figure 2. YRDH003 150.2m ‐ Mineralised Breccia (slate, siderite‐calcite‐quartz‐sphalerite‐galena) Figure 3. YRDH003 153.4m – Mineralised polyphase vein with sphalerite and siderite Yerelina Project Background The Yerelina project area is highly prospective for base metal and silver mineralisation as evidenced by previously identified, high grade mineralisation and historic mine workings within repeated structures over an 8km by 3km area. Core’s analysis of modern satellite imagery and the Company’s detailed heli‐borne magnetic and radiometric survey data have identified that these mineralised structures are potentially part of a large scale system of repeated north/south regional faults (Figure 5). The Adelaide Geosyncline has long been considered prospective for sedimentary basin hosted (MVT) base metal mineralisation styles. Core believes that the mineralisation at Yerelina may represent a surface exposure of part of one of these large regional mineralisation styles. The drill core from the current program will provide valuable information to help unlock and target the interpreted MVT‐style “engine room” that is driving the observed surface mineralisation over this large area (Figure 5). Core has also been awarded a grant of up to $75,000 for drilling as part of the SA Government’s PACE Discovery Drilling 2015 program. A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Figure 4. Drill hole trace and interpreted geological cross section, YRDH003 Great Gladstone Prospect, Yerelina Project South Australia. A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Figure 5. Great Gladstone location, magnetic image and surface mineralised structures in plan view with block model of conceptual geological targets (depth not to scale). Hole_ID Easting Northing RL DIP TAZ Total Depth Completion YRDH001 328171 6672700 403.4 ‐60 111.5 150.6 10/09/2015 YRDH002 330078 6673496 395.6 ‐60 126 348.3 24/09/2015 YRDH003 330082 6673506 397 ‐50 90 210.3 19/09/2015 YRDH004 330083 6673506 397 ‐50 36.5 249.6 28/09/2015 YRDH005 335154 6671835 479 ‐50 84.5 78.1 01/10/2015 Total Metres Drilled: 1037m Table 1: Summary of Yerelina Drilling A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au For further information please contact: Stephen Biggins Managing Director Core Exploration Ltd info@coreexploration.com.au John Field Field Public Relations 08 8234 9555 john@fieldpr.com.au The information in this report that relates to Exploration Results and Mineral Resources is based on information compiled by Stephen Biggins (BSc(Hons)Geol, MBA) as Managing Director of Core Exploration Ltd who is a member of the Australasian Institute of Mining and Metallurgy and is bound by and follows the Institute’s codes and recommended practices. He has sufficient experience which is relevant to the styles of mineralisation and types of deposits under consideration and to the activities being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the “Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves”. Mr. Biggins consents to the inclusion in the report of the matters based on his information in the form and context in which it appears. This report also includes exploration information that was prepared and first disclosed by Core under the JORC Code 2004. It has not been updated since to comply with the JORC Code 2012 on the basis that the information has not materially changed since it was last reported. The information in all previous announcements has been compiled by Mr Stephen Biggins as the Competent Person and who provided his consent for all previous announcements. The information that was reported in announcements previously released under JORC Code 2004 is the announcement dated 19/03/2013 titled “High Grade Lead‐Zinc‐Silver Assays from S.A. Project” A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Yerelina – October 2015– JORC 2012 Section 1 Sampling Techniques and Data (Criteria in this section apply to all succeeding sections.) Criteria 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.  Geological logging by observation of NQ2 core from diamond drilling  Structural logging from oriented core drillholes orientated using electric downhole camera  Core orientated using a Coretel system  Structural measurements established from measured alpha betas  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. Drilling techniques Drill sample recovery  In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘RC 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.  Drill type (eg core, RC, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc).  Method of recording and assessing core and chip sample recoveries and results assessed.  The drill core from these recently completed drillholes is currently being transported from site to Adelaide, where the core will be cut, sampled and submitted for laboratory assay. Assay results are expected in approximately 4-6 weeks.  NQ2 core  Core orientated using electric downhole camera (refer Table1)  Visual geological, recovery and structural logging data A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Criteria JORC Code explanation Commentary  Measures taken to maximise sample recovery and ensure representative nature of the samples.  A visual estimate of recovery over was recorded. Generally good recovery - no bias expected  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 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. Subsampling 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 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.  Drill core are qualitatively logged and photographed  Qualitative logging of Core includes lithology, colour, mineralogy, description, marker horizons, weathering, texture, alteration and mineralization  Quantitative logging of orientated core includes structural alpha beta angles Total length of the hole logged  Geological observation only  The drill core from these recently completed drillholes is currently being transported from site to Adelaide, where the core will be cut, sampled and submitted for laboratory assay. Assay results are expected in approximately 4-6 weeks.level being attributed to this initial sampling.  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. A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Criteria Quality of assay data and laboratory tests JORC Code explanation Commentary  Whether sample sizes are appropriate to the grain size of the material being sampled.  The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total.  Geological observation only  For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc.  The drill core from these recently completed drillholes is currently being transported from site to Adelaide, where the core will be cut, sampled and submitted for laboratory assay. Assay results are expected in approximately 4-6 weeks.  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 data, data entry procedures, data verification, data storage (physical and electronic) protocols.  The drill core from these recently completed drillholes is currently being transported from site to Adelaide, where the core will be cut, sampled and submitted for laboratory assay. Assay results are expected in approximately 4-6 weeks. Discuss any adjustment to assay data. Location of  Geological observations and primary data is captured by Core geologists directly into an in-house referential and integrated database system designed and managed by the Exploration Manager. All assay data is cross-validated within the database by various integrity scripts and externally using MapInfo drill hole validation checks including interval integrity checks.  Accuracy and quality of surveys used to locate drill holes (collar and  All coordinates are recorded in GDA 94 MGA Zone 53. A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Criteria JORC Code explanation Commentary data points down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation.  Specification of the grid system used.  Quality and adequacy of topographic control.  Collar location undertaken by Core Exploration staff using a handheld Garmin GPS this tool has an accuracy of approximately 3m.  Topographic control uses the DTM generated by the airborne helimag survey conducted over the area by Core in 2013 Downhole surveys were undertaken using an electronic survey camera system Data spacing and distribution Orientation of data in relation to geological structure Sample security Audits or reviews  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.  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 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.  The measures taken to ensure sample security.  The results of any audits or reviews of sampling techniques and data.  Initial geological observations only of core  Geological observations only  Refer Figure 4. for interpreted geological and structural orientations  The drill core from these recently completed drillholes is currently being transported from site to secure site in Adelaide, where the core will be cut, sampled and submitted for laboratory assay. Assay results are expected in approximately 4-6 weeks.  No audits or reviews have been undertaken A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Section 2 Reporting of Exploration Results (Criteria listed in the preceding section also apply to this section.) Criteria 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.  Yerelina is contained within EL 5015 that is 100% held by Sturt Exploration Pty Ltd a wholly owned subsidiary of Core Exploration Ltd. Exploration done by other parties  Acknowledgment and appraisal of exploration by other parties. Geology  Deposit type, geological setting and style of mineralisation. 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 collar o elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar o dip and azimuth of the hole o down hole length and interception depth o hole length.  Core Exploration manages EL 5015.  EL 5015 is located on Mt Freeling Station.  All drilling was undertaken outside of Heritage, Conservation or National Parks on EL 5015.  Modern exploration is very limited in the Yerelina area however extensive historical workings dating back to 1908 are evident as a number of shafts and drives  The mineralisation style targeted is sediment hosted base metal mineralisation within an antiformal structure of Tapley Hill Formation  Refer Table 1.  If the exclusion of this information is justified on the basis that the A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Criteria Data aggregation methods JORC Code explanation    Relationship between mineralisatio n widths and intercept lengths    Diagrams  Balanced reporting  Other substantive exploration data  Commentary 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. 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. 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’). 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. 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. 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  Preliminary geological observations of core only  Drilling intersects the mineralised zone at an angle (refer Figure 4). Estimated true width of the mineralised breccia zone is approximately 75 % of intersected width.  Refer figures and table in announcement  Drill core either side of the breccia zone is shown in Figure 6 and drill trace in Figure 4.  Exploration activity is very limited at Yerelina however CXO collected heli-magnetic and radiometric data in 2012, undertook previous rockchip sampling of anomalous gossans / historical mullock piles and submitted a limited number of samples for petrology. Two other recent drill holes at Great Gladstone are interpreted to not reach A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au Criteria JORC Code explanation Commentary Further work deleterious or contaminating substances.  The nature and scale of planned further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling). target.  Subject to Board approval further drilling may be undertaken  Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. A 26 Gray Ct, Adelaide SA 5000 | T (08) 7324 2987 | E info@coreexploration.com.au www.coreexploration.com.au