ENGLEWOOD, CO, Feb. 6, 2012 /CNW/ - Alacer Gold Corp. ("Alacer" or the
"Company") [TSX:ASR, ASX:AQG] announces updated Mineral Resource and
Reserve estimates for its Higginsville Gold Operations in Australia.
The Mineral Reserve estimate has increased by 164,000 ounces (net of
mining depletion over 18 months) to 7.9 million tonnes at 3.5g/t gold,
containing 875,000 ounces, as detailed in the table below.
Mineral Reserve for Higginsville Operations as at December 31, 2011 |
| Proven | Probable | Total Reserves |
| Tonnes (kt) | Grade (g/t) | Ounces (koz) | Tonnes (kt) | Grade (g/t) | Ounces (koz) | Tonnes (kt) | Grade (g/t) | Ounces (koz) |
Trident Underground
|
595
|
5.0
|
96
|
3,108
|
4.5
|
447
| 3,703 | 4.6 | 543 |
Chalice Underground
|
-
|
-
|
-
|
1,049
|
4.3
|
144
| 1,049 | 4.3 | 144 |
Fairplay Underground
|
-
|
-
|
-
|
139
|
6.4
|
29
| 139 | 6.4 | 29 |
Open Pits
|
-
|
-
|
-
|
2,704
|
1.7
|
151
| 2,704 | 1.7 | 151 |
Stockpiles*
|
282
|
0.8
|
7
|
-
|
-
|
-
| 282 | 0.8 | 7 |
Total | 877 | 3.7 | 104 | 7,000 | 3.4 | 771 | 7,877 | 3.5 | 875 |
Note: Rounding differences will occur. The Mineral Reserve methodology
and cut-off grades are summarised in the Technical Procedural Section below.The above estimate is based on a gold price of US$1,350 per ounce
(*Includes satellite and Trident low-grade stockpiles).
Edward Dowling, President and CEO of Alacer, stated "This updated
Higginsville Reserve is the culmination of extensive drilling and other
work since July 2010. The net increase of 164,000 ounces is quite
significant considering that the Higginsville Gold Operations produced
more than 230,000 ounces of gold during the 18 months to December 2011.
The increased reserves are largely due to down-plunge extensions of the
Trident orebody. The Trident Reserve was about 500,000 ounces when
mining started four years ago, more than 500,000 ounces have now been
produced from Trident, and the Trident reserve remains more than
500,000 ounces.
It is important to note that the Measured and Indicated Resources for
Trident and Chalice total a combined 5.7Mt at 4.9g/t gold, containing
895,000 ounces. Further drilling should progressively convert more
resources to reserves as well as continuing to extend both resources.
These efforts take time, but we are excited about the likelihood of
additional high-margin ores as demonstrated by the recent high-grade
discovery at Corona within the Higginsville Line of Lode.
An increasing proportion of Higginsville feed should be high-grade ore
from underground mines following the ramp-up of Chalice ore production
later this year. This will take Higginsville a long way towards the
target of processing 1.5Mtpa at a head grade of 4.5g/t gold, thus
producing approximately 200,000 ounces per annum."
The primary components of the net Reserve increase of 164,000 ounces
since the previous (July 2010) estimate are:
-
Despite Trident being the predominant ore source for Higginsville, the
Trident Underground Mineral Reserve increased by 47,000 ounces largely
as a result of additional ounces in the Artemis and Helios Lodes,
partially offset by mining depleting the Western Zone, Apollo and
Athena Lodes.
-
The Chalice Mineral Reserve increased by 26,000 ounces and reflects the
identification of the new lodes in the footwall to the main Olympus
Lode. The grade has decreased slightly due to additional drilling and
conversion to reserves of resources up-dip of the Olympus Lode.
-
The updated estimate includes a maiden Fairplay Underground Mineral
Reserve of 29,000 ounces. This relatively high-grade reserve would
potentially be accessed from the floor of the planned Fairplay Pit.
-
Systematic evaluation of existing Mineral Resources has increased
open-pit Mineral Reserves by a total of 79,000 ounces, predominantly
from the Pluto, Musket, Mitchell and Vine deposits.
The updated Mineral Reserve was estimated at a gold price of US$1,350
per ounce, compared with $1,200 per ounce for the July 2010 Mineral
Reserve.
The Higginsville Mineral Resource was previously stated at July 1, 2011.
This previous estimate has been adjusted to reflect mining depletion
totaling 61,302 ounces over the six months to December 31, 2011. The
updated estimate is tabulated below.
Mineral Resource for Higginsville Operations as at December 31, 2011 |
| Measured | Indicated | Measured & Indicated | Inferred |
Asset / Project | Tonnes (kt) | Au Grade (g/t) | Au Ozs (koz) | Tonnes (kt) | Au Grade (g/t) | Au Ozs (koz) | Tonnes (kt) | Au Grade (g/t) | Au Ozs (koz) | Tonnes (kt) | Au Grade (g/t) | Au Ozs (koz) |
Trident
|
1,252
|
4.6
|
187
|
3,159
|
5.2
|
525
| 4,411 | 5.0 | 711 |
625
|
3.9
|
79
|
Chalice
|
-
|
-
|
-
|
1,250
|
4.6
|
184
| 1,250 | 4.6 | 184 |
336
|
4.4
|
48
|
Fairplay Area
|
-
|
-
|
-
|
2,669
|
1.9
|
165
| 2,669 | 1.9 | 165 |
145
|
2.1
|
10
|
Palaeochannels
|
-
|
-
|
-
|
1,203
|
2.1
|
81
| 1,203 | 2.1 | 81 |
121
|
1.8
|
7
|
Lake Cowan
|
-
|
-
|
-
|
1,773
|
1.6
|
92
| 1,773 | 1.6 | 92 |
56
|
1.1
|
2
|
Other
|
194
|
0.7
|
4
|
434
|
2.6
|
36
| 628 | 2.0 | 40 |
923
|
1.7
|
50
|
Total | 1,445 | 4.1 | 191 | 10,489 | 3.2 | 1,083 | 11,934 | 3.3 | 1,274 | 2,205 | 2.8 | 196 |
Note: Rounding differences will occur. Resource methodology and cut-off
grades are summarised in the Technical Procedural Section below.
Mineral Resources are quoted inclusive of Mineral Reserves.
Further Mineral Resource and Reserve Updates
Alacer intends to provide an updated Çöpler Mineral Resource estimate
during Q1 2012.
An updated Mineral Reserve estimate for the South Kalgoorlie Operations
is expected to be announced following completion of underground mining
feasibility studies for the Mt Marion West and HBJ deposits, and review
by the Alacer Board of the South Kalgoorlie Expansion Project.
Technical Procedural Information
The information in this report which relates to Exploration Results and
the Mineral Resources is based on information prepared by Chris Newman,
a full-time employee of Alacer, who is a Member of the Australasian
Institute of Mining and Metallurgy and a Member of the Australian
Institute of Geoscientists. Mr Newman has sufficient experience which
is relevant to the style of mineralization and type of deposit under
consideration and to the activity which is being undertaking to qualify
as a Competent Person as defined in the 2004 Edition of the
"Australasian Code for Reporting of Exploration Results, Mineral
Resources and Ore Reserves" and a qualified person pursuant to National
Instrument 43-101 of the Canadian Securities Administrators. Mr Newman
consents to the inclusion in the report of the matters based on this
information in the form and context in which it appears.
The information in this report which relates to Mineral Reserves is
based on information prepared by Paul Thompson, a full-time employee of
Alacer, who is a Fellow of the Australasian Institute of Mining and
Metallurgy. Mr Thompson has sufficient experience which is relevant to
the style of mineralization and type of deposit under consideration and
to the activity which is being undertaking to qualify as a Competent
Person as defined in the 2004 Edition of the "Australasian Code for
Reporting of Exploration Results, Mineral Resources and Ore Reserves"
and a qualified person pursuant to National Instrument 43-101 of the
Canadian Securities Administrators. Mr Thompson consents to the
inclusion in the report of the matters based on this information in the
form and context in which it appears.
Trident Resource Estimation Methodology
Drillhole data used in the Trident Resource comprised predominantly
underground and surface diamond holes, with some RC and underground
sludge holes used. All diamond drillhole collar locations were surveyed
by contract mine surveyors. Drillholes were routinely surveyed downhole
using techniques ranging from Eastman single shot and Reflex single
shot cameras to gyroscopic downhole surveying equipment. Drillhole
spacing for the majority of the Resource ranged from 10m x 15m to 60m x
60m.
Drill core was logged (lithology, alteration, structure, mineralization,
veining) in detail then stored and validated in electronic databases.
Following logging, the drill core was sawn half core and submitted for
assaying. Dependant on the orebody geometry and size, sample lengths
were constrained by geology, alteration or structural boundaries with
lengths varying between 0.5m to 1.1m.
Gold analysis of the samples was undertaken using a combination of 1kg
LeachWell, 500g Pulverise and Leach (PAL) and 50g Fire Assay. Industry
standard reference material and blanks were utilised to check on
laboratory assay quality control.
Assays were composited to 1 metre lengths and assessed for appropriate
top-cuts. The Athena domains were assigned various top-cuts (Athena 10
& 40 - 250g/t gold; Athena 30 - 350g/t gold and Athena 50 - 90g/t
gold); the Artemis domains were assigned a top-cut of 100g/t gold;
Apollo, Western Zone, Eos, E-Veins, Poseidon and Eastern Zone domains
were assigned a top-cut of 50g/t gold; and Helios domains were assigned
a top-cut of 25g/t gold. All top-cuts were based on composited
drillhole data.
A bulk density of 2.89g/cm3 was applied to all domains hosted within gabbro and mafic assemblages
and the waste rock, based on a total of 453 samples taken throughout
the deposit. The laminated quartz lodes (Athena 10, 30 and 50) had a
2.7g/cm3 bulk density applied to these domains.
The grade estimation methods included ID2 (Western Zone, Eastern Zone,
Eos, E-Veins, Poseidon and Athena 40), ID0 (Athena 10, 30 and 50),
assigned grades based on development mapping and sampling (Athena 10,
30 and 50) and Ordinary Kriging (Apollo). Parent block sizes were set
at 10m *, 10m (y) and 10m (z), with the minimum sub-cell size
dependant on the lode thickness.
A lower cut-off grade of 1.0g/t gold was applied to the thicker
orebodies (Western Zone, Apollo, Athena 40, Helios) whereas a 2.0g/t
gold lower cut-off grade was applied to the thinner Athena, Eos and E
Veins, Eastern Zone, Poseidon and Artemis orebodies to reflect
historical stope-mining methodologies.
The Resource estimate has been classified based on data density, data
quality, confidence in the geological interpretation and confidence in
the estimation.
Chalice Resource Estimation Methodology
Drillhole data used in the Chalice Resource comprised predominantly
surface and minor underground diamond holes. All of Alacer's diamond
drillhole collar locations were surveyed by contract mine surveyors
using a RTK GPS. Where identified, historical drillhole collar
locations were surveyed using a RTK GPS, with no reliable records
available for the collar survey methods for the historical holes.
Alacer drillholes were routinely surveyed downhole using gyroscopic
surveying equipment. No reliable data exist for the downhole surveying
technique utilised for the historic drillholes. Drillhole spacing for
the majority of the Resource ranges from 20m x 20m to 40m x 40m.
Drill core was logged (lithology, alteration, structure, mineralization,
veining) in detail then stored and validated in electronic databases.
Following logging, the drill core was sawn to half core and submitted
for assaying. The sample lengths were constrained by geology,
alteration or structural boundaries with lengths varying from 0.4m to
1.0m.
Gold analysis of the samples was undertaken using a combination of
predominantly Fire Assay (20 - 50g charges), Aqua Regia and 1kg
LeachWell. Industry standard reference material and blanks were
utilised to check on laboratory assay quality control, although no
reliable QA/QC data was located for the sampling completed prior to
Alacer.
Assays were composited to 1 metre lengths and assessed for appropriate
top-cuts. The Atlas domain was assigned a top-cut of 25g/t gold; the
Olympus domains were assigned a top-cut of 60g/t Gold; with the Olympus
Hangingwall and Footwall domains assigned various top-cuts if there
were extreme values present in the dataset. All top-cuts were based on
composited drill-hole data.
A bulk density of 3.03g/cm3 was applied to the Olympus domains; 3.03g/cm3 to the Atlas domain; 3.02g/cm3 to the un-mineralized amphibolites; and 2.61g/cm3 to the felsic units, based on 69 samples through the various
domains/lithologies at Chalice. The grade estimation method used was
ID2 for all the mineralized domains. Parent block sizes were set at 10m
*, 10m (y) and 10m (z), with the minimum sub-cell size set at 1.5m
*, 2.5m (y) and 2.5m (z).
A lower cut-off grade of 2.0g/t gold was applied to the main domains
(Atlas and Olympus) whereas a 3.0 g/t gold lower cut-off grade was
applied to the thinner hangingwall and footwall domains to reflect
likely mining and haulage scenarios.
The Resource estimate has been classified based on data density, data
quality, confidence in the geological interpretation and confidence in
the estimation.
Other Higginsville Resources Estimation Methodology
Drillhole data used in the Vine, Fairplay and Lake Cowan Resources
comprised predominantly surface RC and minor surface diamond holes.
All of Alacer's drillhole collar locations were surveyed by contract
mine surveyors using either a differential or RTK GPS. There are no
reliable records available for the collar survey methods for the
historical holes. Alacer drillholes were routinely surveyed downhole
via an Eastman Single Shot survey camera at 30m intervals. No reliable
data exist for the down-hole surveying technique utilised for the
historic drillholes. Drillhole spacing for the majority of these
Resources vary between 10m x 10m and 40m x 40m.
For the RC holes, logging of lithology, alteration, mineralization and
veining was undertaken on 1 metre composited RC samples. The diamond
drill core was logged in detail for lithology, structure, alteration,
mineralization and veining. All logs have been stored and validated in
electronic databases.
RC samples were collected as 1 metre composites via an on-rig cyclone
and splitter assembly and then submitted for assaying. After logging,
the drill core was sawn half core and submitted for assaying, with the
sample lengths constrained by geology, alteration or structural
boundaries with lengths varying from 0.4m to 1.0m.
Gold analysis of the samples was undertaken using a combination of 500g
Pulverise and Leach (PAL), Fire Assay (20 - 50g charges), Aqua Regia
and 1kg LeachWell. Industry standard reference material and blanks were
utilised to check on laboratory assay quality control, although no
reliable QA/QC data was located for the sampling completed prior to
Alacer.
Assays were composited to 1 metre lengths and assessed for appropriate
top-cuts. For Vine, the 550 domain was assigned a top-cut of 250g/t
gold with a top-cut of 20g/t gold assigned to the samples in the 650
domain. For the Fairplay region, a top-cut of 40g/t gold was assigned
to the main Fairplay domains, 25g/t gold for the Fairplay East domains
and 60g/t gold for the Fairplay North domains. For the three deposits
at Lake Cowan (Josephine, Napolean and Louis) a top-cut of 15g/t gold
was applied. All top-cuts were based on composited drillhole data.
As a significant proportion of these deposits are situated near the
surface, various bulk densities were applied based on the degree of
weathering and the host rock type. For the lodes contained within
completely weathered material, a bulk density of 1.6g/cm3 was applied, for the transitional saprock zone a bulk density of
2.2g/cm3 was applied and for fresh rock a bulk density of 2.85g/cm3 was applied. A bulk density of 2.7g/cm3 was applied to the quartz-rich domains at Vine. Bulk density testwork
at Vine and Fairplay confirmed the validity of these bulk densities for
the various zones in the weathering profile as well as the fresh rock.
The grade estimation method varied between the three deposits depending
on the drill density and style of mineralization. At Vine, a rolling
average (ID) method was adopted for the nuggetty gold distribution of
the 550 lode, with an ID2 method utilised for the remaining Vine
mineralized domains. At Fairplay an ID2 interpolation method was used
for all the domains. The Lake Cowan resource estimate utilised a
mixture of ID2 and Ordinary Kriging for the various lodes. Parent
block sizes were set at 10m *, 10m (y) and 10m (z) for all the
resources at Fairplay and Lake Cowan, with the minimum sub-cell size
set at 1.0m *, 1.0m (y) and 0.5m (z). For Vine the parent block
sizes were set at 5m *, 5m (y) and 5m (z), with the minimum sub-cell
size set at 1.0m *, 1.0m (y) and 1.0m (z).
A lower cut-off grade of 0.8g/t gold was applied to the domains at Lake
Cowan whereas a 0.5g/t gold lower cut-off grade was applied to the Vine
and Fairplay resources to reflect likely mining, haulage and processing
scenarios.
The Resource estimate has been classified based on data density, data
quality, confidence in the geological interpretation and confidence in
the estimation.
Underground and Open Pit Reserve Estimation
- Mining parameters - All underground reserve physicals were compiled from first principle
applications - with stope shapes constructed from manually digitised
2.5m vertical increments. All stope shapes represent "Drill and Blast
ready" profiles and have been depleted of development physicals.
Generic hangingwall and footwall offsets have been used for each mining
area in addition to dilution parameters associated with nearby fault
domains, development intersections and adjacent ground conditions. Open
pits have been initially frame-worked from Whittle shells, with
subsequent refinement to produce open pit designs. All open pits have
specific design parameters to account for localised conditions as well
as oxide / fresh rock material.
- Geotechnical parameters - Geotechnical analysis and review has been completed for each mining
area to determine the appropriate stable underground mining spans and
pit wall angles based on rock type, rock mass conditions and mining
sequence / methodology. Experience from mining the Trident orebody and
from several existing open pits was used to validate design parameters,
whereby appropriate geotechnical data comprised of back analysis of
existing underground and open pits, geotechnical mapping and
geotechnical drilling. Additionally, new Reserve mining areas are
geotechnically assessed based upon available diamond core and insitu
stress measurements enabling the calculation of theoretical stable
spans. This work is undertaken with the guidance of Higginsville's
external consultant with key findings and recommendations documented.
- Metallurgical parameters - Trident and several open pits in the current reserve have been mined
and processed in recent history. Assumed processing recoveries were
97% for Trident, 94% for Chalice and an average of 89% for other open
pit and underground reserves. Metallurgical testwork was completed
where no existing plant performance information was available.
- Economic Parameters - In order to define the profitability of the assets appropriate
commodity parameters were applied. In the case of underground
parameters separate cut-off grades were calculated for each mining
method per orebody type in order for the analysis to account for
variations in costings. Where appropriate historical costs were
applied. A single cut-off was used for pit optimisation. Additional
private royalties where applied where appropriate. A gold price of
$1,350/oz was used to optimize these projects. Due to the short-term
schedule of the Vine Open Pit, a spot price of $1,700/oz was utilised.
- Mining Costs - The mining costs were derived from either current mining operations
or, where contracts were not existing, from current industry standards
/ quotes gathered from a number of external sources. For the
underground reserves, a majority of the costings were determined from
the existing mining contractor's schedule of rates (Australian Contract
Mining - ACM). Open pit costs were gathered from current operations as
well as indicative benchmark rates from Alacer's South Kalgoorlie
Operation.
- Processing Costs - Processing costs for reserves were based on processing costs from the
existing Higginsville gold plant at a processing rate of 1.35 Mtpa.
- Capital Costs - Capital costs are largely associated with pre-stripping for open pits
and for development and infrastructure for the underground mines. All
capital costs were accounted for in the mine specific NPV calculations
as well as the macro Higginsville calculations. Capital costings were
derived from either existing Higginsville contracts and / or external
quotes.
- Current Mineral Reserve figures are stated as at December 31, 2011 with depletion by production where relevant. A comparison with the
previous reserve is tabulated below.
Table 2: Higginsville - Mineral Reserves Comparison |
| Previous* | As at December 31, 2011 | Change |
Asset / Project | Tonnes (kt) | Au Grade (g/t) | Contained Au Ounces (koz) | Tonnes (kt) | Au Grade (g/t) | Contained Au Ounces (koz) | Tonnes (kt) | Au Grade (g/t) | Contained Au Ounces (koz) |
Trident Underground
|
3,219
|
4.8
|
496
|
3,703
|
4.6
|
543
|
484
|
(0.2)
|
47
|
Chalice Underground
|
727
|
5.1
|
118
|
1,049
|
4.3
|
144
|
322
|
(0.8)
|
26
|
Fairplay Underground
|
-
|
-
|
-
|
139
|
6.4
|
29
|
139
|
6.4
|
29
|
Open Pits
|
1,226
|
2.0
|
78
|
2,704
|
1.7
|
151
|
1,478
|
(0.3)
|
73
|
Stockpiles
|
505
|
1.2
|
19
|
282
|
0.8
|
7
|
(223)
|
(0.4)
|
(12)
|
Total | 5,677 | 3.9 | 711 | 7,877 | 3.5 | 875 | 2,200 | (0.4) | 164 |
* The previous Mineral Reserve is at 1 July 2010 and is detailed in NI
43-101 Technical Report of the Mining Operations and Exploration
Tenements of Avoca Resources Limited, Western Australia completed by
SRK Consulting and dated 15 December 2010.
-
There are no known environmental, permitting, legal, taxation, political
or other relevant issues that would materially affect the estimates of
the Mineral Reserves.
-
Due to rounding of figures small discrepancies may exist.
All resource numbers quoted in this release are reported inclusive of
reserves. Mineral Resources that are not Mineral Reserves do not have
demonstrated economic viability.
Cautionary Statements
Certain statements contained in this report constitute forward-looking
information, future oriented financial information, or financial
outlooks (collectively "forward-looking information") within the
meaning of Canadian securities laws. Forward-looking information may
relate to this report and other matters identified in Alacer's public
filings, Alacer's future outlook and anticipated events or results and,
in some cases, can be identified by terminology such as "may", "will",
"could", "should", "expect", "plan", "anticipate", "believe", "intend",
"estimate", "projects", "predict", "potential", "continue" or other
similar expressions concerning matters that are not historical facts
and include, but are not limited in any manner to, those with respect
to proposed exploration, communications with local stakeholders and
community relations, status of negotiations of joint ventures,
commodity prices, mineral resources, mineral reserves, realization of
mineral reserves, existence or realization of mineral resource
estimates, the timing and amount of future production, timing of
studies and analysis, the timing of construction of the proposed mines
and process facilities, capital and operating expenditures, economic
conditions, availability of sufficient financing, exploration plans and
any and all other timing, exploration, development, operational,
financial, economic, legal, social, regulatory and political factors
that may influence future events or conditions. Such forward-looking
statements are based on a number of material factors and assumptions,
including, but not limited in any manner, those disclosed in any other
Alacer filings, and include exploration results and the ability to
explore, the ultimate determination of mineral reserves, availability
and final receipt of required approvals, titles, licenses and permits,
sufficient working capital to develop and operate the mines, access to
adequate services and supplies, commodity prices, ability to meet
production targets, foreign currency exchange rates, interest rates,
access to capital markets and associated cost of funds, availability of
a qualified work force, ability to negotiate, finalize and execute
relevant agreements, lack of social opposition to the mines, lack of
legal challenges with respect to the property or the Company and the
ultimate ability to mine, process and sell mineral products on
economically favorable terms. While we consider these assumptions to be
reasonable based on information currently available to us, they may
prove to be incorrect. Actual results may vary from such
forward-looking information for a variety of reasons, including but not
limited to risks and uncertainties disclosed in other Alacer filings at
www.sedar.com and other unforeseen events or circumstances. Other than as required by
law, Alacer does not intend, and undertakes no obligation to update any
forward-looking information to reflect, among other things, new
information or future events.
<p> Edward Dowling or Lisa Maestas - North America at +1-303-292-1299<br/> Roger Howe - Australia at +61-405-419-139 </p>