LUNDIN MINING PROVIDES EXPLORATION UPDATE INCLUDING AN INITIAL RESOURCE ESTIMATE FOR THE SEMBLANA COPPER DEPOSIT


Toronto, December 15, 2011 (TSX: LUN; OMX: LUMI) Lundin Mining Corporation
(“Lundin Mining” or the “Company”) is pleased to provide an interim report on
exploration activities including an initial Inferred Resource for the Semblana
Copper Deposit located adjacent to its 100% owned Neves-Corvo mine in southern
Portugal.

 

Highlights

  • Initial Inferred Resource for the Semblana Copper Deposit of 6.58 million
    tonnes at a grade of 3.0% copper and 24 g/t silver is reported in
    accordance with the definitions in the Canadian National Instrument 43-101
    (NI 43-101).
  • Potential for width, strike and depth extensions of this initial
    copper-silver resource is considered excellent. 
  • Hole PSM46B-1, which is included in the initial resource reported herein,
    intercepted 20.5 metres of massive sulphides grading 6.1% Cu; including a
    high-grade interval of 5.0 metres of 16.0% Cu. 
  • A new zone of high-grade copper sulphides, which is not included in the
    initial resource reported herein, has been discovered approximately 300
    metres to the south of the initial resource.  Step-out hole PSR42, at a
    starting depth of approximately 930 metres, intercepted 14 metres of
    massive sulphides including a 5.0 metre interval grading 4.6% Cu. A second
    step-out hole, PSQ44, located approximately 80 metres to the northeast of
    PSR42, intercepted 8.4 metres grading 5.2% Cu at a starting depth of 920
    metres.
  • A new copper discovery has been made approximately 1.4 km south of Semblana
    and approximately 1.3 km southeast of the Zambujal copper-zinc orebody.
     Hole SCA26, intercepted a 32.5 metre thick section of strong
    stockwork-type copper sulphides grading 2.2% Cu including a higher grade
    interval of 11.0 metres grading 3.9% Cu.
  • At the Clare Project in Ireland, a potential new zone of high-grade
    zinc-lead-silver mineralization, including 16.3 metres of 10.2% Zn+Pb, 22 g
    /t Ag in Hole 11-3679-161 at a starting depth of 601 metres, has been
    discovered approximately 750 metres west of the original Kilbricken
    discovery hole.
  • Also in Ireland, a new grassroots zinc-lead discovery has been made in the
    Lakelands Project, located in County Leitrim, 80 km west of the Tara Mine.


Semblana Copper Deposit

A total of 72,450 metres in 75 diamond drill holes, including 52 parent holes
and 23 wedged holes, has now been completed at the Semblana Copper Deposit,
extending the zone of copper-silver mineralization that was first discovered in
September, 2010.  Although additional resource expansion drilling is planned
for 2012, an initial resource estimate has been prepared for Semblana to aid in
mining concept and underground access optimization studies that are ongoing and
are expected to be completed in early Q1/2012.

 

The Semblana Copper Deposit comprises two zones:

  • A recently discovered, high-grade massive copper sulphide zone at the
    southern end of the deposit of 0.64 million tonnes grading 6.2% copper and
    62 g/t silver, overlying a stockwork copper sulphide zone.  This massive
    copper sulphide zone measures approximately 150 metres north to south and
    100 metres east to west, and is open to the east and west for expansion.
  • An extensive stockwork-type copper sulphide zone of 5.94 million tonnes
    grading 2.6% copper and 20 g/t silver.  This zone occurs as one continuous
    zone measuring approximately 700 metres north to south and 250 metres east
    to west.  Given the wide current spacing of drill holes, the zone appears
    to be open to the east and west.

 

This initial copper resource estimate for Semblana is a progress report on an
on-going exploration project that in mid-2010 first discovered thick but barren
massive sulphides, followed later in 2010 by the discovery of copper
stockwork-type sulphides, and more recently by the discovery of high-grade
massive copper sulphides.  The highest grade massive copper sulphide intercept
drilled to date was just recently completed; Hole PSM46B-1 intercepted 20.5
metres of massive sulphides grading 6.1% Cu, 4.0% Zn, 1.2% Pb, 75 g/t Ag, 0.23
g/t Au including a high-grade interval of 5.0 metres of 16.0% Cu, 10.1% Zn,
1.7% Pb, 110 g/t Ag, 0.37 g/t Au.  See attached table for the complete set of
Semblana drill results.

Dr. Neil O’Brien, Senior Vice President of Exploration and New Business
Development for Lundin Mining commented, “Our sustained efforts over the past
year have led to the discovery of two centres of very high grade massive copper
sulphides that are open to expansion.  It is our expectation that the discovery
of these massive copper sulphide zones will lead us to a significantly greater
resource, and in turn, result in the fast-tracking of the underground
development at Neves-Corvo to Semblana.”

Significant drill intercepts of zinc-lead, gold and tin have also been made but
drilling was designed around developing a copper resource and therefore no
resources for these other metals have been estimated.  Please see attached full
table of drill results and plan maps displaying drillhole locations, an outline
of the initial Semblana resource and exploration targets.

New Discoveries - Neves-Corvo Near-Mine Exploration 

As a result of a high-resolution 3D seismic survey completed earlier this year
over a 21 square kilometre area, several new exploration targets near the
Neves-Corvo mine were identified.  Since last reporting, two significant new
discoveries have been made:

  • 3D seismics clearly indicate a southerly extension of the Semblana
    Deposit.Follow-up drill-testing has confirmed the existence of the
    “Semblana South Extension”.Hole PSR42 intercepted a 5.0 metre thick
    interval of massive copper sulphides starting at a depth of 935 metres and
    grading 4.6% Cu, 3.1% Zn, 0.2% Pb, 65 g/t Ag, 1.47 g/t Au; it is visually
    similar to the massive copper sulphides that comprise the initial Semblana
    resource and so is believed to represent a continuation.
  • Hole SCA26, located approximately 1.4 km south of Semblana and
    approximately 1.3 km southeast of the Zambujal copper-zinc orebody,
    intercepted a 32.5 metre thick section of strong stockwork copper sulphide
    mineralization starting at a depth of 751 metres and grading 2.2% Cu
    including a higher grade interval of 11.0 metres grading 3.9% Cu.  This
    intercept is especially significant as it suggests the possible nearby
    presence of high-grade massive copper mineralization, also supported by the
    presence of two other mineralized intercepts contained in Holes SDA44-1 and
    PMB01 drilled in 1983 and 1994, respectively. 

 

An aggressive surface drill program is planned for 2012 to test several
high-priority targets including the two mentioned above.

Clare Zinc-Lead-Silver-Copper Project, Ireland

Resource exploration drilling continued at the Kilbricken Deposit, located
within the large Clare property situated in County Clare, Ireland. Significant
new massive sulphide mineralization has been discovered 750 metres west of the
original Kilbricken discovery hole suggesting the edge of a new high-grade
zone.  Significant zinc-lead and now also copper sulphide mineralization has
been intersected in four holes (11-3679-153, -161, -167*, and -171*) drilled on
50 metre centres in this newly discovered zone.  The following table summarizes
the assayed intercepts (true thicknesses) to date from this new discovery:

 

┌───────────┬────────┬──────┬───────────┬──────┬──────┬────────┬────────┬──────┐
│Hole No.   │From (m)│To (m)│Interval   │Zn (%)│Pb (%)│Zn+Pb   │Ag (ppm)│Cu (%)│
│           │        │      │(m)        │      │      │(%)     │        │      │
├───────────┼────────┼──────┼───────────┼──────┼──────┼────────┼────────┼──────┤
│11-3679-153│640.6   │650.2 │9.6        │6.18  │1.65  │7.83    │20      │0.08  │
├───────────┼────────┼──────┼───────────┼──────┼──────┼────────┼────────┼──────┤
│And        │656.5   │659.5 │3.0        │0.02  │0.03  │0.05    │119     │6.80  │
├───────────┼────────┼──────┼───────────┼──────┼──────┼────────┼────────┼──────┤
│11-3679-161│601.0   │617.4 │16.3       │7.14  │3.06  │10.20   │22      │0.10  │
├───────────┼────────┼──────┼───────────┼──────┼──────┼────────┼────────┼──────┤
│And        │624.4   │633.0 │8.6        │12.38 │0.04  │12.42   │18      │0.02  │
└───────────┴────────┴──────┴───────────┴──────┴──────┴────────┴────────┴──────┘

* assays pending for holes 167 and 171                    

Hole 11-3679-167, intercepted two separate high-grade zinc-lead sulphide
intervals of 6.6 and 5.8 metres true thickness, composed of massive and
semi-massive sphalerite, galena and pyrite, in addition to a 12.0 metre thick
interval of high-grade copper sulphide mineralization that is rich in both
chalcopyrite and bornite;  assays are pending.

Zinc-lead-silver sulphide mineralization has now been identified to extend over
an area of 1800 metres by 600 metres at Kilbricken.  The focus of the
exploration drilling this year has been on broader step-out holes aimed at
identifying a large new zone of high-grade zinc-lead-silver mineralization that
is required to provide enough conceptual resource tonnage to warrant an 
intensive resource definition drilling program.  The latest discovery, reported
herein, provides strong evidence that such a large resource is present at
Kilbricken.  The presence of unusually thick and high-grade copper sulphides
underlying the thick, high-grade zinc-lead-silver massive sulphide intervals
intercepted in drillholes 11-3679-153, -161, and -167, is interpreted to be
indicative of a robust and extensive mineralization system present at
Kilbricken.  Please see attached map.

Lakelands Zinc-Lead Project, Ireland

A single scout hole, completed at the Lakelands Property in County Leitrim,
Ireland, intercepted seven metres of zinc-rich sulphide mineralization within
stratigraphically equivalent rocks to the Navan Beds that host the giant
zinc-lead Navan Deposit at Boliden's Tara Mine (initial reserves* of 69.9
million tonnes grading 10.1% zinc and 2.6% lead), located approximately 80 km
to the southeast.  The 7.0 metre mineralized interval contains a higher grade
interval of 4.3 metres (true thickness) grading 3.94% Zn, 0.94% Pb (4.88%
combined Zn+Pb) that includes narrower bedded intervals of higher grade
zinc-lead sulphides.  The mineralization is zinc-rich with pale sphalerite as
the dominant sulphide mineral, displays a stratabound, bedding replacement
nature and is hosted by a succession of calcareous sandstones and siltstones
interbedded with muddy limestones stratigraphically interpreted as Navan Beds
equivalent rocks.

The sulphides were encountered directly beneath a prominent fault juxtaposing
much younger rocks over the mineralized Navan Beds equivalent host rocks.   The
fault clearly terminates the upper portion of the mineralized beds and so the
7.0 metre interval is considered to be a smaller portion of a thicker nearby
zone of mineralization.  There has been no known significant previous drilling
on the property.  Applications for additional prospecting licenses have been
accepted and follow-up drilling is underway. 

* historic initial reserves for Tara Mine are not compliant with NI43-101
regulations

Paul Conibear, President and CEO for Lundin Mining commented, “The resource
growth and discovery of new mineralized zones at Neves-Corvo and in Ireland is
a direct result of the doubling of our exploration spend in 2011 from 2010
levels.  Our exploration team, led by Dr. Neil O’Brien, has carried out focused
and successful programs and we will continue to invest strategically in both
brownfields and greenfields exploration, with some $50 million to be directed
to organically growing our resource base during 2012.”  

 Sampling and Analytical Protocol:

In Portugal, NQ sized drill core was logged, cut in half with a diamond saw and
sampled by Company personnel at its facilities in Portugal at the Neves-Corvo
mine. Prior to the 2011 campaign mineralized intervals are analyzed for a suite
of elements including Zn, Cu, Pb and Sn at the Neves-Corvo laboratory using XRF
methods.  For the 2011 campaign mineralized intervals were analyzed for a
multi-element suite using industry standard ICP methods at ALS Chemex
Laboratory, Vancouver. 

In Ireland, NQ sized drill core was logged, cut in half with a diamond saw and
sampled by Company personnel at its core facility in Ennis, County Clare. 
Mineralized intervals are analyzed for a multi-element suite at the laboratory
using industry standard ICP methods.  Values of Zn, Pb, Cu, Fe, As and Ag
exceeding predetermined threshold values are re-analyzed by conventional assay
methods. 

QA/QC

In both Portugal and Ireland a standardised protocol of quality control sample
insertion using certified reference material, blanks and duplicates are used to
monitor the quality of the sampling process and assay results.

Qualified Persons

Jose Mario Castello Branco, EurGeol, General Manager of Exploration, Iberia,
for Lundin Mining Exploration is a Qualified Person as defined by National
Instrument 43-101 and has reviewed and approved the technical information
contained in this release regarding the near-mine resource exploration
drilling, including the Semblana delineation drilling, at the Neves Corvo mine
in southern Portugal.

Paul Gordon, PGeo (IGI), EurGeol (EFG), Manager, Geology (Ireland) for Lundin
Mining Exploration is a Qualified Person as defined by National Instrument
43-101 and has reviewed and approved the technical information contained in
this release regarding the Clare and Lakelands Projects in Ireland.

The mineral resource estimates for the Semblana Project were prepared by Graham
Greenway, Pr.Sci.Nat., Group Resource Geologist, Lundin Mining, in November
2011. Mr Greenway is a Qualified Person as defined by National Instrument
43-101 and has reviewed and approved the technical information contained in
this release concerning the Semblana Mineral Resource.

About the Semblana Initial Resource Estimate:

The Semblana Deposit occurs between 810 m and 900 m below surface.  The
geological model was created using drill core lithology and assay data with the
mineralisation envelopes being defined using a 0.7% copper cut-off and a
minimum drillhole intersection thickness of 4 m. Metal grades were interpolated
into 3D blocks using Ordinary Kriging or Inverse Power Distance Weighting. The
Mineral Resource was reported above a cut-off of 1.0% copper, as applied at the
Neves-Corvo mine. The effective date of the Semblana resource estimate is 30
November 2011.

 

Tenke Phase II Expansion Technical Report:

The Company is also pleased to announce that the National Instrument 43-101 (NI
43-101) compliant Technical Report in support of the Tenke Phase II Expansion
Study has been filed on SEDAR (www.sedar.com).

 

About Lundin Mining

Lundin Mining Corporation is a diversified Canadian 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 the 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,

Paul Conibear

President and CEO

 

For further information, please contact:

Sophia Shane, Investor Relations North America:  +1-604-689-7842

John Miniotis, Senior Business Analyst:  +1-416-342-5565

Robert Eriksson, Investor Relations Sweden:  +46 8 545 015 50

 

Forward Looking Statements

Certain information contained in this press release, including any information
as to our strategy, projects, plans or future financial or operating
performance and other statements that express management's expectations or
estimates of future performance, constitute "forward-looking statements". All
statements, other than statements of historical fact, are forward-looking
statements. 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.

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