TORONTO, ONTARIO–(Marketwire - Nov. 30, 2010) - Lundin Mining Corporation (TSX:LUN)(OMX:LUMI) (“Lundin Mining” or the “Company”) is pleased to announce further high-grade copper intersections at its recently discovered Semblana copper-rich massive sulphide deposit located adjacent to its 100% owned Neves-Corvo mine in southern Portugal.
Seven additional drill holes have been completed since the discovery news release and base metal assays for three of these holes have been received. Significant intersections from the three assayed holes include:
- 20 metres at 3.47% copper (including 7 metres at 5.48% copper) in hole PSK48;
- 39 metres at 2.59% copper (including 11 metres at 7.02% copper) in hole PSK48-1; and
- 13 metres at 4.14% copper in hole PSK50-2.
Surface exploration drilling has continued to intercept a thick massive sulphide lens underlain by extensive stockwork sulphides, now delineated over an area exceeding 800 x 300 metres. The sulphide deposit is currently constrained by only one hole on the western side, three widely spaced holes on the eastern side and is completely open to the north and south. Please see Attachment A for further information.
Neil O’Brien, Senior Vice President of Exploration and New Business Development for Lundin Mining commented, “Our drilling has now intersected strong sulphide mineralization in 16 holes, six of which contain very significant copper mineralization.
“While we have lots of drilling yet to do, Semblana is growing into the type of high-grade resource that can significantly contribute to future copper production.
“Combined with the current copper resources and nearly 100 million tonnes of zinc resources, the future of Neves Corvo as a leading, long-life copper-zinc producer looks very good,” Dr. O’Brien said.
(Note: as disclosed in August 31, 2010 news release, as of June 30, 2010 total zinc resources at Neves Corvo were 58,047,000 tonnes grading 6.2% zinc in the Measured category, 13,929,000 tonnes grading 6.9% zinc in the Indicated category and 26,791,000 tonnes grading 4.9% zinc in the Inferred category)
Neves-Corvo has two processing plants capable of treating copper and zinc ores. It has a single shaft that is responsible for hoisting of all ore and waste. Shaft capacity has recently been increased to an estimated 4.6 million tonnes per annum and this remains as the strategic constraint to production volume.
Potential future production from Semblana, and any further new discoveries, has to be considered in light of this shaft constraint. Whilst incremental increases may be possible, until significant new infrastructure is constructed the development of Semblana will need to be co-ordinated with existing production and the on-going development of Lombador, potentially necessitating production choices on the basis of highest net return.
Mine development studies, including consideration of the need for a second shaft, are presently constrained by the knowledge available on Lombador, Semblana and other near-mine resources. Lundin Mining’s exploration effort is now being significantly increased to obtain a better understanding of the ultimate potential of Neves-Corvo in order to facilitate these mine development studies.
Neves-Corvo Exploration Strategy
Exploration effort at Neves-Corvo over the last three years has been focussed on the discovery of new copper resources to supplement and replace mature producing orebodies. This has been successful in replacing mined production and adding new copper resources and reserves as well as rapidly expanding the zinc resources in the higher-grade Lombador deposit.
However, Neves-Corvo remains under-explored, particularly at deeper levels (greater than 700 metres below surface), and the ability to plan longer-term infrastructure development is restricted as a result. Drilling from surface accurately to these depths is expensive and slow. It is considered uneconomic to drill at a close enough spacing from surface to support resource estimates on which mine plans can be assessed.
To support long-term mine development and expansion studies, Lundin Mining is pursuing a three-fold exploration strategy at Neves-Corvo as follows:
- The access ramp to the Lombador orebody is being accelerated to reach a depth of 900 metres below surface by Q1 2012. Exploration drives from the ramp will allow in-fill drilling of the copper and zinc resources for detailed mine planning. It will also allow cost effective further exploration that will be key to gaining a full understanding of the zinc, and more importantly copper, mineralisation associated with Lombador.
There remain high-priority exploration targets at Lombador where drill-testing could discover significant additional new resources that would further impact these mine development studies.
In order to fund the development of the ramp, a small upper section of Lombador South has been under-going feasibility studies and is expected to be complete in Q1 2011.
- Semblana is being explored initially from surface with five drill rigs. An 80,000 metre surface drilling program is planned for 2011 which will deliver an initial resource estimate for Semblana prior to the end of 2011. Drilling will be focused on step-out holes to determine the ultimate limit of this large deposit and to search for additional copper-zinc rich zones as well as on in-fill holes to provide data for the resource estimate.
Once Semblana is better understood, access options can be assessed to ensure maximum utilisation of existing infrastructure.
- The discovery of Semblana will significantly contribute to future copper production at Neves Corvo and it has also opened up new target areas for exploration. Accordingly a 24 square kilometre high resolution 3D seismic survey, to cover the entire near-mine area is planned, which will attempt to detect other nearby massive sulphide lenses.
An earlier seismic survey, carried out in 1996, was able to clearly detect the large Lombador massive sulphide lens at depths exceeding 1000 metres.
It is estimated that this program may take as long as three years to complete and that infrastructure development options will be evaluated in parallel to this.
Commenting on the exploration programme at Neves-Corvo Mr. Phil Wright, President and CEO said, “We continue to view Neves-Corvo as under-explored and are very encouraged by the results to-date.
“Our efforts over the last few years have enabled us to replace mined copper production and add to reserves. However, this has generally been at lower-grade which means we have to move more tonnes in order to maintain copper production.
“Semblana is the first time we have seen something enriched in copper at a significant scale that offers the potential of a rejuvenation of Neves-Corvo’s copper business.
“We remain very optimistic on the longevity of our copper and zinc production at Neves-Corvo,” Mr. Wright said.
Sampling and Analytical Protocol:
NQ sized drill core was logged, cut in half with a diamond saw and sampled by Company personnel at its facilities at the Neves-Corvo mine. Mineralized intervals are analyzed for a suite of elements including Zn, Cu, Pb and Sn at the Neves-Corvo laboratory using XRF methods. Bob Carmichael, P.Eng., General Manager, Resource Exploration, is the Qualified Person as defined by National Instrument 43-101 and has reviewed and approved the technical information contained in this release.
About Lundin Mining
Lundin Mining Corporation is a diversified base metals mining company with operations in Portugal, Sweden, Spain and Ireland, producing copper, zinc, lead and nickel. In addition, Lundin Mining holds a development project pipeline which includes expansion projects at its Zinkgruvan and Neves-Corvo mines along with its equity stake in the world class Tenke Fungurume copper/cobalt project in the Democratic Republic of Congo.
On Behalf of the Board,
Phil Wright, President and CEO
Forward Looking Statements
Certain of the statements made and information contained herein is “forward-looking information” within the meaning of the Ontario Securities Act. Forward-looking statements are subject to a variety of risks and uncertainties which could cause actual events or results to differ from those reflected in the forward-looking statements, including, without limitation, risks and uncertainties relating to foreign currency fluctuations; risks inherent in mining including environmental hazards, industrial accidents, unusual or unexpected geological formations, ground control problems and flooding; risks associated with the estimation of mineral resources and reserves and the geology, grade and continuity of mineral deposits; the possibility that future exploration, development or mining results will not be consistent with the Company’s expectations; the potential for and effects of labour disputes or other unanticipated difficulties with or shortages of labour or interruptions in production; actual ore mined varying from estimates of grade, tonnage, dilution and metallurgical and other characteristics; the inherent uncertainty of production and cost estimates and the potential for unexpected costs and expenses, commodity price fluctuations; uncertain political and economic environments; changes in laws or policies, foreign taxation, delays or the inability to obtain necessary governmental permits; and other risks and uncertainties, including those described under Risk Factors Relating to the Company’s Business in the Company’s Annual Information Form and in each management discussion and analysis. Forward-looking information is in addition based on various assumptions including, without limitation, the expectations and beliefs of management, the assumed long term price of copper, nickel, lead and zinc; that the Company can access financing, appropriate equipment and sufficient labour and that the political environment where the Company operates will continue to support the development and operation of mining projects. Should one or more of these risks and uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those described in forward-looking statements. Accordingly, readers are advised not to place undue reliance on forward-looking statements.
Attachment to Lundin Mining Corporation Exploration Update Dated November 29, 2010: Additional Details On Exploration At Semblana
Lundin Mining announced on October 27, 2010 that surface exploration drilling near its Neves-Corvo mine in southern Portugal had discovered a sixth deposit to add to the existing Neves, Corvo, Graça, Zambujal and Lombador sulphide deposits. This new deposit was named Semblana and is located only 1.3 km northeast of the Zambujal orebody in an area which has not previously been drilled. See attached maps.
Since the initial release on October 27, 2010, surface exploration drilling has continued to intercept a thick massive sulphide lens underlain by extensive stockwork sulphides, currently delineated over an area exceeding 800 x 300 metres. The deposit is currently constrained by only one hole on the western side, three widely spaced holes on the eastern side and is completely open to the north and south.
The Semblana massive sulphide lens is currently up to 68 metres thick. The massive sulphide intersections to date are primarily pyrite with moderate grade zinc intervals but only minor concentrations of copper sulphides. However, it is noted that all of the Neves-Corvo massive sulphide lenses are principally composed of pyrite with ore deposits formed as discreet, high-grade copper and/or zinc zones within the larger pyrite envelope. As ongoing drilling provides a better understanding of the grade distribution within the Semblana sulphide deposit, additional base metal zones are likely to be encountered. Silver assays have so far only been received for three holes including hole PSJ44 (8 metres at 4.5% zinc and 124 gpt silver) and hole PSK50-1 (11 metres at 94 gpt silver with low base metal values).
The high-grade copper intersections lie within the stockwork mineralization underlying the massive sulphide lens which is common in the Neves-Corvo deposits. Tin is commonly enriched in these high-grade copper intervals, as noted in the table below, and indium is also elevated.
All drill results are summarized in the table below:
||No Significant Values
||No Significant Values
Drill intersections provided above are interpreted to be true thicknesses. Results of additional borehole electromagnetic (BHEM) surveying indicate that the conductive sulphide mineralization is still significantly larger than the drilling has so far outlined.
To view accompanying maps, please click on the following link: http://media3.marketwire.com/docs/lundinmaps30.pdf