Capstone Adds 219 Million Pounds of Copper in M&I Mineral Resource at Minto Mine
By Capstone Mining Corp., PRNESunday, May 29, 2011
VANCOUVER, May 30, 2011 -
- At a 0.5% Copper Cut-off Grade, Total Mineral Resources at the Minto
Mine now Exceeds 1 Billion Pounds of Copper
Capstone Mining Corp. ("Capstone") (TSX: CS) today announced the result
of a National Instrument 43-101 compliant mineral resource estimate for the
Wildfire/Copper Keel area at the Minto Mine in Yukon, Canada. Wildfire/Copper
Keel is now recognized as a southeastwardly extension of the Area 2/118
deposit which is currently being pre-stripped in preparation for mining. The
combined Area 2/118/Copper Keel/Wildfire mineral resources are now recognized
as a single mineral deposit and will be referred to as the Minto South
Deposit ("MSD"). The Copper Keel region of this larger deposit model is still
open and exploration drilling is currently in progress with two drills.
"The exploration success at Minto continues to be translated into mineral
resource additions that support the near term growth strategy at our mining
operations. Since 2006 the Minto Mine has realized steady expansion through a
program of discovery and feasibility in a series of phases that have
increased mine life and throughput. Capstone plans to follow up this latest
mineral resource addition with a new Pre-Feasibility Study (Minto - Phase VI
PFS) that is expected to start in the third quarter of 2011," said Brad
Mercer, Vice-President, Exploration for Capstone.
Additional Mineral Resources by Class in the Wildfire/Copper Keel Region
of MSD at a 0.5% Cu Cut-off Grade ("COG")**
Classification Tonnes Copper Gold Silver Contained Contained Contained
Cu Gold Silver
(000's)* (%) (g/t) (g/t) (000's (000's (000's
lbs)* oz)* oz)*
Measured (M) 3,176 1.09 0.39 3.35 76,071 40.0 341.8
Indicated (I) 6,198 1.04 0.34 3.18 142,498 67.9 633.9
Total (M&I) 9,374 1.06 0.36 3.24 218,570 107.9 975.6
Additional Inferred 1,113 0.98 0.33 3.22 24,066 11.6 115.3
*Rounded to nearest thousand; totals may not sum exactly due to rounding.
**Exclusive of all previous resources estimated for Area 2/118 deposit
Mineral resources that are not mineral reserves do not have demonstrated
economic viability. Mineral resource estimates do not account for
mineability, selectivity, mining loss and dilution. These mineral resource
estimates include inferred mineral resources that are normally considered too
speculative geologically to have economic considerations applied to them that
would enable them to be categorized as mineral reserves. There is also no
certainty that these inferred mineral resources will be converted to measured
and indicated categories through further drilling, or into mineral reserves,
once economic considerations are applied.
Minto South Deposit (MSD) - Mineral Resource Estimate
Geological modelling using new drill holes from 2010 and 2011 (partial)
in the Wildfire/Copper Keel area indicate that Wildfire and Copper Keel are a
southeast extension of mineralization located on the Area 2 side of the
previous Area 2/118 resource model and not separate deposits as initially
thought. Approximately 134 new drill holes were added to the existing
database of 235 holes to estimate a mineral resource for the entire MSD.
These new data indicate a continuity of mineralization between Copper Keel
mineralization and the deeper levels of Area 2. The new model indicates that
there was also continuity of mineralization between Wildfire and the
shallower levels of Area 2 before erosion removed mineralization and created
the false impressions of a gap between the two deposits.
The 219 million pounds of copper gained in M&I resource class and
attributable to the Wildfire/Copper Keel area of the MSD block model was
determined by tabulating all mineralized blocks at the stated cut-off grade
that lie outside of the southeast perimeter of the previous Area 2/118 block
model.
The table below is a tabulation of all mineral resources by class for the
combined Minto South Deposit at a 0.5% Cu COG.
Total Mineral Resources by Class for the Minto South Deposit at a 0.5%
COG***
Classification Tonnes Copper Gold Silver Contained Contained Contained
Cu Gold Silver
(000's)* (%) (g/t) (g/t) (000's (000's (000's
lbs)* oz)* oz)*
Measured (M) 10,091 1.23 0.46 4.1 274,474 149.7 1,319.8
Indicated (I) 26,295 0.96 0.31 3.3 552,706 263.1 2,812.9
Total (M&I) 36,386 1.03 0.35 3.5 827,181 412.8 4,132.4
Additional
Inferred 7,429 0.82 0.23 2.8 134,296 55.0 666.3
*Rounded to nearest thousand; totals may not sum exactly due to rounding.
***This tabulation includes mineral resources previous outlined for the Area
2/118 deposit. For new mineral resources added by the new interpolation
please refer to the previous table.
Total Undeveloped Resources for the Minto Mine
The following table details the total of all of the undeveloped mineral
resources on the property at a COG of 0.5% Cu. The table includes Minto
North, Minto East, Minto South and Ridgetop as listed form north to south.
Any resources remaining in the Minto Main deposit are excluded because mining
of this pit has been completed. Existing ore stockpiles are also excluded. At
the end of this news release is also a table of the undeveloped mineral
resources for Minto at select copper COGs. Estimated grade and tonnage stated
at copper COGs below 0.5% copper are for illustrative purposes only; to show
the sensitivity of the mineral resource to changing copper COGs. Some of the
estimated grade and tonnage at lower COGs may lie outside of any constraints
imposed for "reasonableness of mining" purposes with respect to National
Instrument 43-101.
Mineral resources at higher cut-off grades are for illustrative purposes
and do not necessarily imply a higher potential for economic extraction. Only
those mineral reserves determined by previous feasibility studies are
currently considered economically viable. The property-wide mineral resource
numbers reported herein are inclusive of all previously defined mineral
reserves that are currently supported by previous pre-feasibility work.
Please refer to the Technical Report titled Minto Phase V Preliminary
Feasibility Study Technical Report dated December 15, 2010 filed on SEDAR for
any further discussion about mineral reserves at Minto. A new pre-feasibility
study (Phase VI) is anticipated to start in the third quarter of 2011 to
apply economic considerations to the newly estimated mineral resources in the
Wildfire/Copper Keel extension of the MSD.
Total Mineral Resources by Class for all Deposits Outside of the Minto
Main Pit at a 0.5% Cu COG****
Classification Tonnes Copper Gold Silver Contained Contained Contained
Cu Gold Silver
(000's)* (%) (g/t) (g/t) (000's (000's (000's
lbs)* oz)* oz)*
Measured (M) 13,465 1.33 0.53 4.3 395,209 228 1,881
Indicated (I) 30,828 0.98 0.33 3.4 664,794 325 3,334
Total (M&I) 44,293 1.09 0.39 3.7 1,060,002 553 5,215
Additional
Inferred 8,360 0.88 0.27 2.9 162,429 72 792
*Rounded to nearest thousand; totals may not sum exactly due to rounding.
****Excludes any resources remaining in the Minto Main Deposit, where mining
as now ceased, as well as existing stockpiles of ore originating in the Minto
Main Deposit.
Mineral Resource Estimate Methodology
The mineral resource estimate for the Wildfire/Copper Keel addition to
the Minto South Deposit reported herein was prepared by SRK Consulting of
Vancouver. The estimate was completed in Gemcom Software GEMS(c) using a
three dimensional block model (10 m by 10 m by 3 m (vertical) block size).
The mineralization was interpreted into nine distinct domains, modelled as
wireframes and used as hard boundaries to constrain estimation.
Geostatistical analysis was completed on the 1.5m composite assay data for
each of the metals, and variograms were defined for each domain of
mineralization. The grades for copper and gold were interpolated into the
block model using ordinary kriging method. Whereas the silver grades were
interpolated using the inverse distance squared method only. Interpolated
results are reported in measured, indicated and inferred categories and are
based on continuity of the mineralization and sample density.
Minto South Deposit (MSD) — Mineral Resources by Class at Select Copper
Cut-offs
Contained Contained Contained
Copper Gold Silver
Cut-Off Tonnes Copper Gold Silver (000's (000's (000's
Classif-
ication (Cu%) (000's)* (%) (g/t) (g/t) lbs)* oz)* oz)*
Measured
(M) >2.0 1,370 2.59 1.14 9.20 78,095 50 402
>1.5 2,884 2.14 0.89 7.38 135,922 82 680
>1.0 5,134 1.74 0.70 5.93 197,205 114 966
>0.5 10,091 1.23 0.47 4.12 274,474 150 1,320
>0.4 12,070 1.10 0.41 3.67 294,001 157 1,406
>0.3 15,019 0.96 0.35 3.15 316,578 165 1,502
>0.2 19,147 0.80 0.28 2.62 338,964 173 1,596
Indicated
(I) >2.0 1,311 2.61 0.93 9.62 75,354 39 397
>1.5 3,243 2.07 0.73 7.60 148,205 76 782
>1.0 8,137 1.55 0.55 5.61 277,998 143 1,462
>0.5 26,295 0.95 0.31 3.32 552,706 263 2,813
>0.4 36,046 0.82 0.26 2.83 648,579 299 3,284
>0.3 50,105 0.68 0.21 2.37 756,391 338 3,829
>0.2 68,147 0.57 0.17 1.97 854,355 370 4,333
Minto South Deposit (MSD) — Mineral Resources by Class at Select Copper
Cut-offs - continued
Contained Contained Contained
Copper Gold Silver
Cut-Off Tonnes Copper Gold Silver (000's (000's (000's
Classif-
ication (Cu%) (000's)* (%) (g/t) (g/t) lbs)* oz)* oz)*
Sub-total
(M&I)** >2.0 2,681 2.60 1.03 9.41 153,449 89 799
>1.5 6,127 2.10 0.81 7.50 284,127 159 1,462
>1.0 13,272 1.62 0.61 5.74 475,204 258 2,428
>0.5 36,386 1.03 0.35 3.54 827,180 413 4,132
>0.4 48,116 0.89 0.30 3.04 942,581 457 4,691
>0.3 65,123 0.75 0.24 2.55 1,072,969 503 5,332
>0.2 87,294 0.62 0.19 2.11 1,193,318 543 5,929
Additional
Inferred >2.0 136 2.71 1.37 15.13 8,087 5 55
>1.5 482 1.96 0.79 9.36 20,847 11 134
>1.0 1,312 1.48 0.52 6.22 42,841 21 250
>0.5 7,429 0.82 0.23 2.82 134,296 55 667
>0.4 11,307 0.69 0.18 2.33 172,320 66 844
>0.3 17,300 0.57 0.14 1.88 218,193 78 1,046
>0.2 25,850 0.46 0.11 1.52 263,831 90 1,267
*Rounded to nearest thousand; totals may not sum exactly due to rounding.
**Exclusive of all previous resources estimated for Area 2/118 deposit
Quality Assurance
The technical information in this news release has been prepared in
accordance with Canadian regulatory requirements set out in National
Instrument 43-101 ("NI 43-101") and reviewed by Brad Mercer, P. Geol., Vice
President, Exploration for Capstone, the person who oversees exploration
activities on the Minto Mine property.
The mineral resource estimate reported herein for the Area
2/118/Wildfire/Copper Keel deposit was estimated by Wayne Barnett,
Pr.Sci.Nat. and Marek Nowak, P. Eng. of SRK Consulting. Dr. Barnett is the
Independent Qualified Person under NI 43-101 responsible for the MSD mineral
resource estimate and has reviewed the information in this release in respect
of the MSD mineral resource estimate. The database used to estimate the
Wildfire/Copper Keel deposit was audited by SRK. SRK is of the opinion that
the current drilling information is sufficiently reliable to extend with
confidence the boundaries of the mineralized domains from Area 2 into
Wildfire/Copper Keel, and that the assaying data is sufficiently reliable to
support estimating mineral resources. The mineral resources presented herein
have been estimated in conformity with generally accepted CIM "Estimation of
Mineral Resource and Mineral Reserves Best Practices" guidelines and are
reported in accordance with Canadian Securities Administrators' National
Instrument 43-101. Mineral resources are not mineral reserves and do not have
demonstrated economic viability. In the opinion of SRK, the block model
resource estimate and resource classification reported herein are a
reasonable representation of the mineral resources at Wildfire/Copper Keel
deposit at the current level of sampling.
With respect to the MSD mineral resource estimate, the analytical method
for the copper and silver analyses is aqua regia digestion of the samples
followed by atomic absorption spectroscopy. Gold is analysed by fire assay
fusion with atomic absorption spectroscopy finish. Analyses are carried out
by ALS Chemex in North Vancouver. When visible gold is noted in drill core
samples or regular fire assay values appear abnormally high, screen metallic
assay method is used to determine the total gold content and gold content of
different size fractions. This is considered industry best practice when
dealing with coarse gold mineralization where a nugget effect is suspected.
This determination is accepted as the most representative value and is used
in the assay database for resource calculations. Blank and standard samples
are used for quality assurance and quality control. Where more than two check
samples assay outside expected ranges, the entire batch is re-assayed. After
the completion of planned drill programs at Minto, random check assays will
be carried out by Acme Analytical of Vancouver.
Cautionary Note Regarding Forward-Looking Information
This document may contain "forward-looking information" within the
meaning of Canadian securities legislation and "forward-looking statements"
within the meaning of the United States Private Securities Litigation Reform
Act of 1995 (collectively, "forward-looking statements"). These
forward-looking statements are made as of the date of this document and
Capstone Mining Corp. (the "Company") does not intend, and does not assume
any obligation, to update these forward-looking statements, except as
required under applicable securities legislation.
Forward-looking statements relate to future events or future performance
and reflect Company management's expectations or beliefs regarding future
events and include, but are not limited to, statements with respect to the
estimation of mineral reserves and resources, the realization of mineral
reserve estimates, the timing and amount of estimated future production,
costs of production, capital expenditures, success of mining operations,
environmental risks, unanticipated reclamation expenses, title disputes or
claims and limitations on insurance coverage. In certain cases,
forward-looking statements can be identified by the use of words such as
"plans", "expects" or "does not expect", "is expected", "budget",
"scheduled", "estimates", "forecasts", "intends", "anticipates" or "does not
anticipate", or "believes", or variations of such words and phrases or
statements that certain actions, events or results "may", "could", "would",
"might" or "will be taken", "occur" or "be achieved" or the negative of these
terms or comparable terminology. By their very nature forward-looking
statements involve known and unknown risks, uncertainties and other factors
which may cause the actual results, performance or achievements of the
Company to be materially different from any future results, performance or
achievements expressed or implied by the forward-looking statements. Such
factors include, among others, risks related to actual results of current
exploration activities; changes in project parameters as plans continue to be
refined; future prices of mineral resources; possible variations in ore
reserves, grade or recovery rates; accidents, labour disputes and other risks
of the mining industry; delays in obtaining governmental approvals or
financing or in the completion of development or construction activities; as
well as those factors detailed from time to time in the Company's interim and
annual financial statements and management's discussion and analysis of those
statements, all of which are filed and available for review on SEDAR at
www.sedar.com. Although the Company has attempted to identify
important factors that could cause actual actions, events or results to
differ materially from those described in forward-looking statements, there
may be other factors that cause actions, events or results not to be as
anticipated, estimated or intended. There can be no assurance that
forward-looking statements will prove to be accurate, as actual results and
future events could differ materially from those anticipated in such
statements.
Accordingly, readers should not place undue reliance on forward-looking
statements.
For further information:
Capstone Mining Corp.
Cindy Burnett, VP, Investor Relations
Telephone: +1-604-637-8157
Email: cburnett@capstonemining.com
Website: www.capstonemining.com
.
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