Cloncurry Project: Bedford Resource Upgrade
Altona Mining Limited (“Altona” or the “Company” - https://www.commodity-tv.net/c/mid,5428,Company_Updates/?v=297328) is pleased to announce a new Mineral Resource estimate for the Bedford deposit at the Company’s 100% owned Cloncurry Copper Project near Mt Isa in Queensland. Bedford is located 6 kilometres southeast of the planned Little Eva open pit mine and processing plant and lies within granted mining leases.
The new resource estimate is: 4.8 million tonnes at 0.80% copper and 0.21g/t gold for 38,000 tonnes of contained copper and 32,000 ounces contained gold.
The resource is reported at a 0.3% lower cut-off grade and is classified as indicated and inferred. A full tabulation is given in Tables 1 and 2. A detailed summary of the supporting data and methodology is given in Appendix 1, being Table 1 of the 2012 Edition of the JORC Code.
The global Mineral Resource for the Cloncurry Project is now:
290 million tonnes at 0.58% copper, 0.05g/t gold for 1.67 million tonnes of contained copper and 0.4 million ounces contained gold (Appendix 2).
The new Bedford Mineral Resource estimate is based on a new geological model informed by detailed surface geochemical and geological mapping. The new model was also informed by two additional diamond drillholes drilled for metallurgical samples and geotechnical studies.
The Mineral Resource reports sulphide ore only and extends from 20 metres to 140 metres below surface. An oxide cap ranging from surface to depths of 20 to 30 metres is excluded from the resource estimate.
The increase from the 2012 estimate resulted primarily from better understanding of continuity and geometry. The mineralised structures were able to be better defined based on mapping of surface workings and high resolution copper-in-soil sampling. An increase in tonnage also resulted from new bulk density data from diamond core as opposed to prior conservative estimates.
The Bedford deposit is part of the Little Eva mine development and is scheduled to commence production in year 2 of the mine plan. The new model indicates the potential to increase Bedford ore reserves and pit optimisations are planned as part of the project optimisation.
The Bedford deposit is an Iron-Oxide-Copper Gold (IOCG) style mineral system typical of the Cloncurry district. The neighbouring Little Eva deposit is a more typical IOCG deposit with similarities to the major Ernest Henry deposit located 70 kilometres to the southeast.
The deposit is hosted within a steep, west-dipping shear zone striking north to north-northeast. The shear zone varies from 50 to 120 metres wide within which there are en-echelon and overlapping arrays of mineralised structures. Mineralisation is best developed in two separate zones, ‘Bedford North’ and ‘Bedford South’ within a strike length of 2.5 kilometres. Individual mineralised structures associated with ore grade mineralisation (>0.3% copper) have true widths ranging from 5 to 12 metres.
Host stratigraphy comprises a north to north-northeast striking, moderate to steep west dipping interlayered sequence of amphibolite and biotite schist. The stratigraphy is intruded by narrow planar concordant granite and pegmatoidal dykes/sills.
Bedford South mineralised structures are largely layer parallel. At Bedford North the mineralised structures are interpreted to trend north-south, crosscutting north-northeast striking stratigraphy. Secondary north-northeast linking structures are found along bedding/foliation. Magnetite-biotite alteration assemblages with quartz veining are concentrated in the mineralised structures with a strongly feldspar-hematite altered footwall below.
The dominant ore mineral is coarse-grained chalcopyrite (with minor magnetite, pyrite, pyrrhotite and gold) which occurs within quartz veins, breccia fill and as disseminations in host rocks.
The deposit is sub-cropping. An irregular 20 to 30 metres thick zone of weathering with secondary copper oxide mineralisation blankets the deposit.
Resource Definition and Modelling
Drilling is mostly at a spacing of approximately 25 metres along strike and 25 metres down dip over the main zones with spacing between drill lines increasing to 100 metres along strike from the main zones. Drilling comprises 99 RC and 2 diamond holes for a total of 10,139 metres drilled. All drill holes were drilled west to east to intersect approximate true widths of mineralisation. RC drilling was completed using a face sampling hammer. A small number of RAB holes (13) were used where no other data were available and resources derived from RAB data are classified as inferred.
Samples were collected routinely on 1 metre intervals for logging and assaying. All samples were submitted for multi-element ICPAES and/or AAS analysis at reputable laboratories. Quality Assurance/Quality Control (QA/QC) samples were routinely inserted and monitored. Quality monitoring ensured that the accuracy and precision of this analysis is acceptable.
3D geological models constructed from surface mapping, detailed surface geochemistry and drilling data were used to constrain resource estimation. Resource estimation was conducted using block model methodologies consistent with planned semi-selective mining parameters. Copper and gold grades were estimated using ordinary kriging at the parent block scale. Post-processing of the data by uniform conditioning was applied to copper to estimate block grades at the selective mining scale.
In-situ bulk density values are based on physical measurements conducted on diamond drill core and on comparitive data from the neighbouring deposits.
Please direct enquiries to:
Alistair Cowden David Tasker Jochen Staiger
Managing Director Professional Public Relations Swiss Resource Capital AG
Altona Mining Limited Perth Tel: +41 71 354 8501
Tel: +61 8 9485 2929 Tel: +61 8 9388 0944 firstname.lastname@example.org
Altona Mining Limited is an ASX listed company focussed on the Cloncurry Project in Queensland, Australia. The Project has Mineral Resources containing some 1.65 million tonnes of copper and 0.41 million ounces of gold. It is envisaged that a 7 million tonnes per annum open pit copper-gold mine and concentrator will be developed at the Project. The development is permitted with proposed annual production(1) of 38,800 tonnes of copper and 17,200 ounces of gold for a minimum of 13 years. A Definitive Feasibility Study was published in March 2014. Altona has completed a Framework Agreement with Sichuan Railway Investment Group to fully fund and develop the Project through its Hong Kong subsidiary, China Sichuan International Investment Limited. The transaction is scheduled to close prior to 31 July 2017.
1Refer to the ASX release ‘Cost Review Delivers Major Upgrade to Little Eva’ dated 13 March 2014 which outlines information in relation to this production target and forecast financial information derived from this production target. The release is available to be viewed at www.altonamining.com or www.asx.com.au. The Company confirms that all the material assumptions underpinning the production target and the forecast financial information derived from the production target referred to in the above-mentioned release continue to apply and have not materially changed.
Competent Persons Statement
The information in this report that relates to Exploration Targets, Exploration Results, Mineral Resources or Ore Reserves is based on a report prepared by Mr Frank Browning, MSci (Hons), MSc, GAIG a full time employee of Altona, has five years relevant experience but is not a full member of AIG. The report was supervised and audited by Mr Roland Bartsch, BSc (Hons), MSc, MAusIMM and this public release is based on information compiled by Mr Bartsch. Mr Bartsch is a full time employee of the Company and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaking 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 Bartsch consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.
Table 1: Bedford Mineral Resource as a 0.3% copper cut-off
Note: Totals may not match sub-totals due to rounding.
Table 2: Bedford Mineral Resource reported above a range of cut-off grades
R Mineral Resource reported cut-off grade.
Table 3: Comparison of Bedford Mineral Resource estimates above a cut-off grade of 0.3% copper