Goldrush Announces 99 Percent increase of Oxide Gold Resource at the Ronguen Gold Deposit, Burkina Faso, West Africa.
(via Thenewswire.ca)
Vancouver, British Columbia: Goldrush Resources Ltd. (TSX-V: GOD)
("Goldrush" or the "Company") is pleased to
announce that it has received a new mineral resource statement for its
Ronguen gold deposit in Burkina Faso. For oxide gold resources, the
new resource contains 150,000 ounces of gold in the Measured category
(4.143 million tonnes grading 1.12 grams of gold per tonne ("gpt
Au"); 159,000 ounces of gold in the Indicated category (3.861
million tonnes grading 1.28 gpt Au); and 8,000 ounces in the Inferred
category (136,000 tonnes grading 1.91 gpt Au) using a cut-off grade of
0.4 gpt gold. In addition, the bottom of the conceptual pit shell
used to constrain the mineral resource statement for the Ronguen
deposit is estimated to contain 23,000 ounces of gold in the Measured
and Indicated categories in fresh rock (483,000 tonnes grading 1.51
gpt Au) and 44,000 ounces of gold in the Inferred category (754,000
tonnes grading 1.83 gpt Au), at a cut-off grade of 0.7 gpt Au.
Ronguen is located on Goldrush's Kongoussi 1 and Tikare permits, 100
kilometres north of the capital city of Ouagadougou, 45 kilometres
east of Cluff Gold's Kalsaka heap leach gold mine and 10 kilometres
northwest of High River Gold's Bissa gold mine which is currently in
development. Ronguen enjoys proximity to paved highways and the Lac
Bam water supply and is within three kilometres of the southern
boundary of the regional centre of Kongoussi, (the capital of Bam
province), which has an approximate population of 45,000.
Len Brownlie Ph.D, President and CEO of Goldrush commented: "The
oxidized portion of the new gold resource, amenable to low processing
cost heap leaching, has nearly doubled relative to the 2008 initial
mineral resource statement from 160,000 inferred ounces to 309,000
combined measured and indicated ounces and an additional 8,000
inferred ounces. In addition to substantially increasing the size of
the oxide mineral resource, the work completed by Goldrush has
significantly increased the quality of the mineral resources as most
of the oxide portion of the deposit is now classified into the
Measured and Indicated categories, while the initial (2008) mineral
resource statement contained only inferred ounces.
We are very encouraged by the potential to develop a heap leach, open
pit operation at Ronguen. We intend to complete a Preliminary Economic
Assessment as we continue to explore the "blue sky"
potential related to this thrust fault hosted deposit where targets
for additional mineralization are located on the potential extension
of the South Zone, at depth in the Main Zone and on a parallel zone
located within one kilometre to the north of the Main Zone, as well as
at unexplored and underexplored areas of potential on the Kongoussi 1
and Tikare permits."
The mineral resource statement was prepared by SRK Consulting (Canada)
Inc. ("SRK") and relied on an exploration database
consisting of 245 reverse circulation ("RC") drill holes
totalling 21,782 metres, 57 HQ core holes totalling 7,079 metres and
38 trenches totalling 3,862 metres. The vast majority of the drill
holes are angled and shallow, with a total hole length of generally
< 120 metres, and tested little of the fresh rock depth potential
of the deposit.
Table 1: Mineral Resource Statement* for the Ronguen Gold Deposit,
Burkina Faso, SRK Consulting May 2012.
-------------------------------------------------------------------
|Classification |Cut-Off |Quantity |Grade |Contained Metal|
| |-----------------------------------------------|
| |Au (gpt)|('000 tonnes)|Au (gpt)|(Gold ounces) |
|-----------------------------------------------------------------|
|Measured Mineral |? |? |? |? |
|Resources | | | | |
|-----------------------------------------------------------------|
|Saprolite / |0.4 |4,143 |1.12 |150,000 |
|Saprock | | | | |
|-----------------------------------------------------------------|
|Fresh Rock |0.7 |138 |1.14 |5,000 |
|-----------------------------------------------------------------|
|Total Measured |? |4,281 |1.12 |155,000 |
|-----------------------------------------------------------------|
|Indicated Mineral|? |? |? |? |
|Resources | | | | |
|-----------------------------------------------------------------|
|Saprolite / |0.4 |3,861 |1.28 |159,000 |
|Saprock | | | | |
|-----------------------------------------------------------------|
|Fresh Rock |0.7 |345 |1.66 |18,000 |
|-----------------------------------------------------------------|
|Total Indicated |? |4,206 |1.31 |177,000 |
|-----------------------------------------------------------------|
|Total Measured |? |8,487 |1.22 |332,000 |
|and | | | | |
|Indicated | | | | |
|-----------------------------------------------------------------|
|Inferred Mineral |? |? |? |? |
|Resources | | | | |
|-----------------------------------------------------------------|
|Saprolite / |0.4 |136 |1.91 |8,000 |
|Saprock | | | | |
|-----------------------------------------------------------------|
|Fresh Rock |0.7 |754 |1.83 |44,000 |
|-----------------------------------------------------------------|
|Total Inferred |? |890 |1.85 |52,000 |
|-----------------------------------------------------------------|
|*Mineral |
|resources are |
|not mineral |
|reserves and do |
|not have |
|demonstrated |
|economic |
|viability. |
|All figures |
|have been |
|rounded to |
|reflect the |
|relative |
|accuracy of the |
|estimates. |
|Reported at a |
|cut-off grade |
|of 0.4?gpt |
|gold in |
|saprolite/saprock |
|and 0.7 gpt |
|gold in fresh |
|rock within a |
|conceptual pit |
|shell optimized |
|considering a |
|gold price of |
|US$1,550 per |
|ounce of gold, |
|metallurgical |
|recovery of 85 |
|percent in |
|saprolite/saprock |
|and 80 percent |
|in fresh rock. |
|The |
|saprolite/saprock |
|extends to the |
|base of the |
|moderately |
|weathered zone |
|and the fresh |
|rock |
|mineral |
|resources |
|extend below |
|that surface. |
-------------------------------------------------------------------
The significant changes in mineral resources between April 2008 and
May 2012 include:
? An increase in the overall quantity of saprolite/saprock mineral
resources;
? A significant upgrade in classification from Inferred to Measured
and Indicated; and
? An increase in overall tonnage and metal content, with a slight
decrease in grade.
Ronguen Deposit Mineralization
The Ronguen gold deposit is located within the northeastern part of
the highly prospective Birimian age Boromo greenstone belt in Burkina
Faso. The local geology at Ronguen is dominated by an east northeast
("ENE") trending metasedimentary sequence consisting of
interlayered siltstone, mudstone and minor conglomerate that are
intruded by plugs, and narrow dykes and sills of gabbroic composition.
The Ronguen mineralized zone is located in the structural hanging wall
of a major ENE thrust fault which recorded a tectonic transport
direction towards the north. The mineralized deformation corridor
represents a major ENE trending reverse fault zone, dipping moderately
towards the south. Gold mineralization is found in both
metasedimentary and mafic intrusive rocks. The gold mineralization is
associated with quartz-carbonate veins/veinlets and with sulphides
occurring as disseminations and patches, and in veinlets. Two sets of
gold-bearing quartz veins are developed: subvertical shear veins
parallel to the shear zone foliation and to the shear zone boundaries,
and subhorizontal extension veins. Small quartz stockworks are present
and represent a part of the gold mineralization.
Ronguen Resource Modelling and Classification Procedure
The Ronguen exploration database was audited by SRK and the
mineralization boundaries were modelled by SRK using a geological
interpretation prepared by Goldrush personnel. The current drilling
information is sufficiently reliable to interpret with confidence the
boundaries of the gold mineralization and the assaying data is
sufficiently reliable to support mineral resource evaluation.
The mineral resources have been estimated using a geostatistical block
modelling approach constrained by gold mineralization wireframes
interpreted from drilling and trenching sampling data. The
exploration database includes: 38 trenches (3,862 metres); 436
inclined rotary air blast boreholes (18,225 metres); 245 angled
reverse circulation boreholes (21,782 metres); and 57 inclined HQ core
boreholes (7,079 metres). Rotary air blast drilling data were not
considered for resource modelling.
Thirteen gold mineralization domains and four weathering profiles were
modelled to constrain resource estimation. A sub-block model was
created in CEA Studio 3, with parent block size set at 10 by 5 by 5
metres. Estimation parameters were selected on the basis of spatial
analysis of gold and specific gravity data. Spatial variance of capped
gold composites was evaluated using semi-variograms with the
normal-score transformation. The block model populated with gold
values using ordinary kriging. Each block was assigned a specific
gravity value using an inverse square distance algorithm. Estimation
parameters were based on variography results.
The mineral resources for the Ronguen gold project have been estimated
in conformity with The Canadian Institute of Mining, Metallurgy and
Petroleum's (CIM) Estimation of Mineral Resource and Mineral Reserves
Best Practices Guidelines and were classified according to the CIM
Definition Standards for Mineral Resources and Mineral Reserves
(December, 2005) by Souvik Banerjee under the supervision of Dr. Jean
Francois Couture, an independent Qualified Person, as defined by
National Instrument 43-101. The classification criteria incorporated
the number of composites used, the estimation pass and number of
informing boreholes. A Measured classification was assigned to
resource blocks estimated during the first estimation pass and
informed by six or more boreholes. Other resource blocks informed
during the first estimation pass were assigned an Indicated
classification. All blocks interpolated during the second and third
estimation pass were assigned an Inferred category.
SRK considers the gold mineralization at Ronguen is amenable to open
pit extraction. In order to determine those portions of the modelled
mineralization that show reasonable prospects for economic extraction
by an open pit, SRK used Datamine NPV Scheduler to evaluate the
profitability of each resource block based on its value. Optimization
parameters were selected based on experience and benchmarking against
similar West Africa projects. Optimization parameters include a gold
price of US$1,550 per ounce. Two processing options were considered:
heap leaching and carbon in leach (CIL).
SRK considers that the oxide gold mineralization would be processed
using a heap leach option and the partly oxidized and fresh rock gold
mineralization could be delivered to a CIL mill. This strategy was
used to deliver the largest reasonable pit envelope to constrain
mineral resource reporting. Heap leach gold recovery was set at 85
percent in the weathered zones (saprolite/saprock) based on
preliminary results of column leach testing. In the absence of
metallurgical testing on fresh rock, CIL recovery was set at 80
percent. Analysis of optimization results suggests that it is
appropriate to report the oxide mineral resources at a cut-off grade
of 0.4 gpt gold and fresh rock mineral resources at a cut-off grade of
0.7 gpt gold. The Mineral Resource Statement for Ronguen gold project
presented in Table 1 includes all Measured, Indicated and Inferred
blocks above cut-off within the resulting conceptual pit shells.
Comparison between the 2008 and 2012 Mineral Resource Statements
In comparing the 2008 and 2012 mineral resource statements, it is
important to note that the two statements are reported using different
constraints. In 2008 the quantities and grade estimates were reported
on the basis of 100 percent metallurgical recovery and were not
constrained inside a conceptual pit envelope. The 2012 mineral
resource statement is reported within a conceptual pit envelope
optimized considering metallurgical recovery. The comparison between
the April 2008 and May 2012 Mineral Resource Statements is presented
in Table 2.
Table 2: Comparison Between 2008* and 2012^ Mineral Resource
Statements
-----------------------------------------------------------------
|? |Cut-Off |Quantity |Grade |Contained |
| |(Au gpt) |(million |(Au gpt) |Metal |
| | |tonnes) | |(Gold |
| | | | |ounces) |
| |---------------------------------------------|
| |2008|2012|2008|2012|2008|2012|2008 |2012 |
|---------------------------------------------------------------|
|Measured Mineral Resources |
|---------------------------------------------------------------|
|Saprolite / |- |0.4 |- |4.14|- |1.12|- |150,000|
|Saprock | | | | | | | | |
|---------------------------------------------------------------|
|Fresh Rock |- |0.7 |- |0.14|- |1.14|- |5,000 |
|---------------------------------------------------------------|
|Indicated Mineral Resources |
|---------------------------------------------------------------|
|Saprolite / |- |0.4 |- |3.86|- |1.28|? |159,000|
|Saprock | | | | | | | | |
|---------------------------------------------------------------|
|Fresh Rock |- |0.7 |- |0.35|- |1.66|? |18,000 |
|---------------------------------------------------------------|
|Inferred Mineral Resources |
|---------------------------------------------------------------|
|Saprolite/Saprock|0.5 |0.4 |3.67|0.14|1.36|1.91|160,000|8,000 |
|---------------------------------------------------------------|
|Fresh Rock |0.5 |0.7 |2.23|0.75|1.24|1.83|89,000 |44,000 |
|---------------------------------------------------------------|
|*The 2008 mineral |
|resource statement |
|was based on the |
|entire resource |
|model, reported to |
|cut-offs considering |
|a gold price of |
|US$685 per ounce of |
|gold and an overall |
|metallurgical |
|recovery of 100 |
|percent; |
|^The 2012 mineral |
|resource statement |
|was based on |
|resources constrained |
|by a conceptual pit |
|shell optimized |
|considering a gold |
|price of US$1,550 per |
|ounce of gold, |
|metallurgical |
|recovery of 85 |
|percent in |
|saprolite/saprock and |
|80 percent in fresh |
|rock. |
-----------------------------------------------------------------
Quality Assurance/Quality Control
Goldrush maintains a rigorous quality control program involving the
use of certified standards from an accredited Canadian laboratory,
inserted blanks, and the use of repeat assays. Details of Goldrush's
quality control program were provided in the Company's News Release
#2010-13, dated October 25, 2010.
The SGS and ALS Chemex laboratories in Ouagadougou, Burkina Faso were
used for sample analysis. Samples are assayed using standard fire
assay techniques on a 50 gram charge with an atomic absorption finish.
For its internal control, SGS inserted two certified standards and
one blank, and analyzed one random duplicate for approximately each 25
samples submitted. For its certified standard and blank samples
included in the QA-QC procedure, Goldrush averaged 11.0% of the total
samples submitted.
For the past year, the RC drilling was contracted to Forages
Technic-Eau/Burkina sarl based in Ouagadougou, Burkina Faso, whereas
the core drilling was contracted to PPI Burkina sarl, also based in
Ouagadougou.
Dr. Jean Francois Couture, an independent qualified person pursuant to
National Instrument 43-101 has reviewed the technical information
herein. The effective date of the mineral resource statement is May
18, 2012. A technical report supporting the mineral resource
statement will be filed on SEDAR within 45 days.
For further information on Goldrush Resources Ltd., shareholders and
other interested parties are invited to visit the Company's website at
www.goldrushresources.ca.
ON BEHALF OF THE BOARD OF DIRECTORS,
GOLDRUSH RESOURCES LTD.
"Len Brownlie"
Len Brownlie - President and Chief Executive Officer
Contact Information:
Don Willoughby, VP Corporate Development: info@goldrushresources.ca
Telephone: 1 - 416-306-5790
About Goldrush: Goldrush is a Canadian mineral exploration company
which has successfully focused on gold exploration in West Africa,
where the company has discovered, and is currently expanding and
defining the 332,000 ounce measured and indicated resource (8,847
million tonnes at a grade of 1.22 g/t Au) and inferred resource of
52,000 ounce (890,000 tonnes at a grade of 1.85 g/t Au) of the Ronguen
gold deposit in Burkina Faso.
FORWARD-LOOKING STATEMENTS: This news release contains certain
"forward-looking statements" within the meaning of Section
21E of the United States Securities Exchange Act of 1934, as amended.
Except for statements of historical fact relating to the company,
certain information contained herein constitutes forward-looking
statements. Forward-looking statements are frequently characterized by
words such as "plan," "expect,"
"project," "intend," "believe,"
"anticipate", "estimate" and other similar words,
or statements that certain events or conditions "may" or
"will" occur. Forward-looking statements are based on the
opinions and estimates of management at the date the statements are
made, and are subject to a variety of risks and uncertainties and
other factors that could cause actual events or results to differ
materially from those projected in the forward-looking statements.
These factors include the inherent risks involved in the exploration
and development of mineral properties, the uncertainties involved in
interpreting drilling results and other geological data, fluctuating
metal prices, the possibility of project cost overruns or
unanticipated costs and expenses, uncertainties relating to the
availability and costs of financing needed in the future and other
factors. The Company undertakes no obligation to update
forward-looking statements if circumstances or management's estimates
or opinions should change. The reader is cautioned not to place undue
reliance on forward-looking statements. Neither the TSX Venture
Exchange nor its Regulation Services Provider (as that term is defined
in policies of the TSX Venture Exchange) accepts responsibility for
the adequacy or accuracy of this release.
Copyright (c) 2012 Thenewswire.ca - All rights reserved.