Updated Wassa Underground Inferred Mineral
Resource estimate totals
5.2 million ounces of
gold
TORONTO, April 12, 2018 /PRNewswire/ - Golden Star
Resources Ltd. (NYSE American: GSS; TSX: GSC; GSE: GSR) ("Golden
Star" or the "Company") announces that it has more than doubled its
Inferred Mineral Resources estimate for its Wassa Underground Gold
Mine ("Wassa Underground") in Ghana.
HIGHLIGHTS
- 3.1 million ounce (147%) increase in Inferred Mineral Resource
estimate at Wassa Underground to 5.2 million ounces of gold (44.9
million tonnes at 3.6 grams per tonne ("g/t") of gold ("Au")),
compared to December 31, 2017
estimate
- 9% increase in grade of Wassa Underground's Inferred Mineral
Resources from 3.3 g/t Au to 3.6 g/t Au
- Updated Inferred Mineral Resource estimate includes results of
9 drill holes reported previously from Wassa Underground, one
deepened hole and 2 new mother holes drilled subsequently
- Assay results from two new mother holes confirm that high grade
gold mineralization extends approximately 75 metres ("m") up dip
and approximately 150 m down dip of
previously intersected high grade zones
- Significant intercepts from the 2 new mother holes were as
follows:
-
- 58.5 m grading 4.8 g/t Au from
1,007.0m in hole BS18DD388M
- 18.3 m grading 4.3 g/t Au from
696.0m in hole BS18DD389M
- Preliminary Economic Assessment ("PEA") on the Inferred Mineral
Resources of Wassa Underground expected to commence late in the
second quarter of 2018
Sam Coetzer, President and
Chief Executive Officer of Golden
Star, commented:
"By more than doubling the Inferred Mineral Resources at
Wassa Underground, we have begun to demonstrate the compelling
potential of this asset in the longer term. We had believed
for some time that Wassa was a larger deposit than previous
estimates suggested and as the deposit remains open to the south,
we believe that further upside exists still. Wassa
Underground has ramped up well and this operational success forms a
solid foundation for the next stage of the mine's growth. We
have under-utilized capacity within Wassa's processing plant and
the southern portion of the deposit represents the potential to
'fill the mill' and increase production. I am looking forward
to commencing the PEA and to exploring further the viability of
this strategy."
Updated Wassa Underground Inferred Mineral Resource
Estimate
The table below displays Wassa's updated Inferred Mineral
Resource estimate and the December 31,
2017 estimate as a comparison.
Wassa Underground
Inferred
Mineral Resource Estimate
|
Tonnes
('000)
|
Grade
(g/t
Au)
|
Ounces
('000)
|
December 31, 2017
estimate
|
19,838
|
3.31
|
2,110
|
Updated estimate as
of April 6, 2018
|
44,909
|
3.57
|
5,153
|
Wassa Complex's Indicated Mineral Resource Estimate
The table below displays Wassa's Indicated Mineral Resource
estimate, which has not been updated since December 31, 2017.
Wassa Complex
Indicated
Mineral Resource Estimate
|
Tonnes
('000)
|
Grade
(g/t Au)
|
Ounces
('000)
|
Wassa Open
Pit
|
26,652
|
1.32
|
1,134
|
Wassa
Underground
|
13,003
|
4.10
|
1,713
|
Wassa
Other
|
4,251
|
3.49
|
476
|
Total December 31,
2017 estimate
|
43,906
|
2.35
|
3,323
|
|
Notes to Mineral
Resource Estimate
|
1.
|
The Mineral Resources
were estimated in compliance with the requirements of National
Instrument ("NI") 43-101.
|
2.
|
The Mineral Resources
for "Wassa Other" include Father Brown, Benso and
Chichiwilli.
|
3.
|
The Wassa Underground
Mineral Resource has been estimated below the $1,450 per ounce of
gold pit shell using an economic gold grade cut-off of 1.62 g/t Au.
The Inferred Mineral Resource has been constrained further by the
high grade mineralized wireframe.
|
4.
|
Mineral Resources
were estimated using optimized pit shells at a gold price of $1,450
per ounce. Other than gold price, the same optimized pit shell
parameters and modifying factors used to determine the mineral
reserves were used to determine the mineral resources.
|
5.
|
The identified
Mineral Resources in the block model are classified according to
the CIM definitions for the Measured, Indicated and Inferred
categories and are constrained by a block cut-off grade calculated
using a gold price of $1,450 per ounce and below the 2017 year-end
topographic surface. The Mineral Resources are reported in situ
without modifying factors applied.
|
6.
|
The stated Mineral
Resources were prepared under the supervision of S. Mitchel Wasel,
Vice President of Exploration for the Company. Mr. Wasel is a
Qualified Person as defined in NI 43-101.
|
7.
|
Numbers may not add
due to rounding.
|
8.
|
Mineral Resources are
not mineral reserves and do not necessarily demonstrate economic
viability.
|
Wassa Underground's Inferred Mineral Resources have increased by
147% to 5.2 million ounces, in the B Shoot South and F Shoot South
areas. The grade of the Inferred Mineral Resources has
increased by 9% to 3.6 g/t Au.
Today's updated Inferred Mineral Resource estimate includes 9
holes that have been released previously1, one deepened
historical hole and two new mother holes, the results of which are
reported today.
Golden Star is drilling the Wassa
South extensions currently and the Company expects that Wassa
Underground's Inferred Mineral Resources will continue to grow with
further step out drilling.
Notes
|
1.
|
Eight holes were
released on February 14, 2018 in the press release entitled,
'Golden Star reports further high grade drilling results from Wassa
Underground' (holes BS17DD385D1-4, BS17DD386M, BS17DD387M, BSDD308M
and BSDD347). One hole was released on September 19, 2017 in
the press release entitled, 'Golden Star extends high grade B Shoot
zone through step out drilling at Wassa Underground Gold Mine'
(hole BS17DD385M).
|
Results from New Mother Holes
The two new mother holes (BS18DD388M and BS18DD389M) were
planned to test the up and down dip extensions of the previously
intersected, high grade mineralization that was reported in hole
BSDD315M (70.5 m grading 5.9 g/t Au
from 742.4
m)1,2, which was drilled in 2014, and in
hole BS17DD385D3 (94.0 m grading 4.4
g/t Au from 1,305.7 m)1,3,
which was drilled in 2017.
The two new holes have confirmed that gold mineralization
extends approximately 150 m down dip
of the zones intersected in the 2017 hole (BS17DD385D3) and
approximately 75 m up dip of the 2014
hole (BSDD315M).
Hole BS18DD388M
The first of the two mother holes, BS18DD388M, reported a
significant intercept of 58.5 m
grading 4.8 g/t Au from 1,007.0
m1. This was approximately 150 m down dip of the two upper zones intersected
in the 2017 hole (BS17DD385D3) of 15.0
m at 3.6 g/t Au from 942.0
m1,3 and 8.1m at
3.6 g/t Au1,3, which confirms that the gold
mineralization extends 150 m further
down dip.
The wider zone intercepted in the 2017 hole (BS17DD385D3) of
94.0 m at 4.4 g/t Au from
1,305.7 m1,3 has been
intersected approximately 250 m down
dip in hole BS18DD388M. However the results suggest the zone
has narrowed, with the hole intersecting two zones of 5.3 m grading 3.0 g/t Au from 1,516.1 m1 and 4.4 m grading 4.6 g/t Au from 1,539.8 m1.
Further directional drilling is currently being conducted from
the BS18DD388M mother hole, with the objective of assessing if gold
mineralization extends down dip and to further delineate the
geometry of this wider zone of gold mineralization.
Hole BS18DD389M
The second of the two mother holes, BS18DD389M, was drilled to
test the up dip extension of the 2014 hole (BSDD315M). This
new hole intersected two mineralized zones approximately
75 m up dip from the wide zone in the
2014 hole (BSDD315M) of 70.5 m at 5.9
g/t Au1,2. The upper zone of this new hole
intersected 18.3 m grading 4.3 g/t Au
from 696.0 m1 and the
lower zone intersected 12.6 m grading
3.7 g/t Au from 747.8
m1. This new hole has confirmed significant
additional volume in this area of the deposit by extending the
mineralization 75 m up dip.
Further drilling is currently being done to test the
limits of these zones both up and down dip.
The full set of drilling results released today is listed in
Appendix A, including the significant intercepts set out
below.
Significant intercepts from two new mother holes (from
surface)
HOLE
ID
|
Azimuth
(°)
|
Dip
(°)
|
From
(m)
|
To
(m)
|
Drilled
Width
(m)
|
~True
Width
(m)
|
Grade Au
(g/t)
|
B Shoot South and
F Shoot South
|
|
|
|
|
BS18DD388M
|
88.9
|
-77.5
|
1007.0
|
1076.3
|
69.3
|
58.5
|
4.8
|
BS18DD389M
|
95.4
|
-62
|
696.0
|
721.0
|
25.0
|
18.3
|
4.3
|
BS18DD389M
|
94.3
|
-61.8
|
747.8
|
765.0
|
17.2
|
12.6
|
3.7
|
Further drill sections showing the location of the drill holes
are available at:
http://www.gsr.com/operations/wassa/wassa-main
Three diamond drill rigs are currently drilling between the
18900 and 19300N drill fences. Golden
Star is planning to drill another step out fence
200 m to the south, on section
18700N, and this drilling is expected to commence late in the
second quarter of 2018, with results anticipated to be released
during the third quarter of 2018.
Notes
|
1.
|
All widths quoted in
this press release are estimated true widths. The full set of
intercepts, including the drilled widths, are included in Appendix
A.
|
2.
|
See press release
entitled, 'Golden Star has continued exploration drilling success
at Wassa', dated July 30, 2014.
|
3.
|
See press release
entitled, 'Golden Star extends high grade B Shoot zone through step
out drilling at Wassa Underground Gold Mine', dated September 19,
2017.
|
Preliminary Economic Assessment
Golden Star is planning to
undertake a PEA on the Inferred Mineral Resources of the Wassa
Underground deposit. The objective of the PEA is to
demonstrate the viability of the Inferred Mineral Resources,
potentially including a new access shaft and new ventilation
infrastructure. As Golden Star has significant under-utilized
capacity in the Wassa processing plant, this additional material
could be processed without the need to build any additional
processing capacity. If the results of the PEA are positive,
it will demonstrate the potential to increase production from the
Wassa complex and to fast track cash flow.
Golden Star expects to commence
work on the PEA late in the second quarter of 2018 and the Company
anticipates it will be completed in the third quarter of 2018.
Background on compilation of updated Inferred Mineral
Resource estimate
The Inferred Mineral Resource estimate was created by
Golden Star with the assistance of
the Cardiff, Wales and
Toronto, Canada offices of SRK
Consulting ("SRK"). SRK Cardiff created the Leapfrog wire
frames with guidance from site geologists and using previous
structural interpretations. Leapfrog Geo 3.1 software was
used for the modeling of the isoclinal fold closures, which are
believed to be the major controls of the high grade gold
mineralization found at Wassa.
SRK Toronto assisted with the resource block model gold grade
estimations. The folded nature of the Wassa model has led to
a resource modeling technique that accounts for the changing
attitude of the mineralized zones by assigning a dip direction and
dip to each of the blocks. The block dip and direction
information controls the search ellipses that are used to look for
drill data for estimation of block grade. This technique is
commonly used in folded ore bodies and is considered appropriate
for estimating gold grades at deposits such as Wassa.
Golden Star has extensive
experience with these modeling techniques as they are utilized in
the stope design process at Wassa Underground. These modeling
techniques are well suited to the geology seen at Wassa and their
accuracy is strengthened through experience gained through
operational reconciliation.
All monetary amounts refer to United States dollars
unless otherwise indicated.
Company Profile:
Golden Star is an established
gold mining company that owns and operates the Wassa and Prestea
mines in Ghana, West Africa. Listed on the NYSE American, the
Toronto Stock Exchange and the Ghanaian Stock Exchange,
Golden Star is focused on delivering
strong margins and free cash flow from its two high grade, low cost
underground mines. Gold production guidance for 2018 is
230,000-255,000 ounces at a cash operating cost per ounce of
$650-730. As the winner of the
PDAC 2018 Environmental and Social Responsibility Award,
Golden Star is committed to leaving
a positive and sustainable legacy in its areas of operation.
APPENDIX A
Assay results received from the drilling of Wassa Underground
targets in the first quarter of 2018
HOLE
ID
|
Azimuth
(°)
|
Dip
(°)
|
From
(m)
|
To
(m)
|
Drilled
Width
(m)
|
~ True
Width
(m)
|
Grade
Au
(g/t)
|
BSDD315
|
97.8
|
-74.5
|
No significant
intersections
|
BS18DD388M
|
88.9
|
-77.5
|
1007.0
|
1076.3
|
69.3
|
58.5
|
4.8
|
BS18DD388M
|
87.8
|
-78.5
|
1097.0
|
1104.0
|
7.0
|
5.8
|
4.8
|
BS18DD388M
|
84.3
|
-78.5
|
1118.0
|
1123.0
|
5.0
|
4.2
|
3.1
|
BS18DD388M
|
82.8
|
-78.7
|
1183.0
|
1191.0
|
8.0
|
6.7
|
3.1
|
BS18DD388M
|
42.6
|
-73.3
|
1516.1
|
1522.1
|
6.0
|
5.3
|
3.0
|
BS18DD388M
|
42.4
|
-73.1
|
1539.8
|
1544.8
|
5.0
|
4.4
|
4.6
|
BS18DD389M
|
91.3
|
-67.2
|
260.2
|
264.2
|
4.0
|
2.7
|
3.7
|
BS18DD389M
|
92.7
|
-65.3
|
384.5
|
390.5
|
6.0
|
4.1
|
11.1
|
BS18DD389M
|
92.4
|
-64.7
|
433.0
|
436.0
|
3.0
|
2.1
|
6.7
|
BS18DD389M
|
93.9
|
-63.8
|
481.0
|
485.5
|
4.5
|
3.2
|
9.6
|
BS18DD389M
|
95.4
|
-63.4
|
503.0
|
510.0
|
7.0
|
5.0
|
2.6
|
BS18DD389M
|
95.4
|
-62
|
696.0
|
721.0
|
25.0
|
18.3
|
4.3
|
BS18DD389M
|
94.3
|
-61.8
|
747.8
|
765.0
|
17.2
|
12.6
|
3.7
|
BS18DD389M
|
93.5
|
-61.8
|
771.3
|
776.3
|
5.0
|
3.7
|
3.5
|
BS18DD389M
|
92.8
|
-61.3
|
808.5
|
814.5
|
6.0
|
4.4
|
10.3
|
Statements Regarding Forward-Looking Information
Some statements contained in this news release are
"forward-looking statements" within the meaning of the Private
Securities Litigation Reform Act of 1995 and "forward looking
information" within the meaning of Canadian securities laws.
Forward looking statements and information include but are not
limited to, statements and information regarding: the timing of
commencement of work on the PEA; the ability to achieve Wassa
Underground's next stage of growth; the growth of Wassa
Underground's Inferred Mineral Resources through further step-out
drilling; the ability to utilize greater capacity at Wassa's
processing plant and increase production; the drilling at 18700N
and 19300N to commence in the second quarter of 2018; the timing of
results from the drilling at 18700N and 19300N; the timing for
completion of the PEA; the potential results of the PEA; and
production guidance and cash operating cost guidance for
2018. Generally, forward-looking information and statements
can be identified by the use of forward-looking terminology such as
"plans", "expects", "is expected", "budget", "scheduled",
"estimates", "forecasts", "intends", "anticipates", "believes" or
variations of such words and phrases (including negative or
grammatical variations) or statements that certain actions, events
or results "may", "could", "would", "might" or "will be taken",
"occur" or "be achieved" or the negative connotation thereof.
Investors are cautioned that forward-looking statements and
information are inherently uncertain and involve risks, assumptions
and uncertainties that could cause actual facts to differ
materially. There can be no assurance that future developments
affecting the Company will be those anticipated by
management. Please refer to the discussion of these and other
factors in Management's Discussion and Analysis of financial
conditions and results of operations for the year ended
December 31, 2017. Additional
and/or updated factors will be included in our annual information
form for the year ended December 31,
2017 which will be filed on SEDAR
at www.sedar.com. The forecasts contained in this press
release constitute management's current estimates, as of the date
of this press release, with respect to the matters covered
thereby. We expect that these estimates will change as new
information is received. While we may elect to update these
estimates at any time, we do not undertake any estimate at any
particular time or in response to any particular event.
Technical Information
The Mineral Resource estimates have been compiled by the
Company's technical personnel in accordance with definitions and
guidelines set out in the Definition Standards for Mineral
Resources and Mineral Reserves adopted by the Canadian
Institute of Mining, Metallurgy, and Petroleum and as required
by Canada's National Instrument 43-101 – Standards of
Disclosure for Mineral Projects ("NI 43-101").
The Mineral Resource technical contents of this press release
have been reviewed and approved by S. Mitchel Wasel, BSc Geology, a
"Qualified Person" pursuant to NI 43-101. Mr. Wasel is Vice
President Exploration for Golden
Star and an active member of the Australasian Institute
of Mining and Metallurgy. The 2018 and 2017 estimates of
Mineral Resources were prepared under the supervision of Mr.
Wasel.
Additional scientific and technical information relating to the
mineral properties referenced in this news release are contained in
the following current technical reports for those properties
available at www.sedar.com: (i) Wassa - "NI 43-101 Technical
Report on feasibility study of the Wassa open pit mine and
underground project in Ghana" effective date December 31,
2014; (ii) Bogoso/Prestea - "NI 43-101 Technical Report on
Resources and Reserves, Golden Star Resources, Bogoso/Prestea
Gold Mine, Ghana" dated March 28, 2018.
The results for Wassa Underground stated herein are based on the
analysis of saw-split HQ/NQ diamond half core or a three kilogram
single stage riffle split of a nominal 25 to 30 kg Reverse
Circulation chip sample which has been sampled over nominal one
meter intervals (adjusted where necessary for mineralized
structures). Sample preparation and analyses have been carried out
at SGS or Intertek Laboratories in Tarkwa, which are
independent from Golden Star, using
a 1,000 gram slurry of sample and tap water which is prepared and
subjected to an accelerated cyanide leach (LEACHWELL). The sample
is then rolled for twelve hours before being allowed to settle. An
aliquot of solution is then taken, gold extracted into Di-iso Butyl
Keytone (DiBK), and determined by flame Atomic Absorption
Spectrophotometry (AAS). Detection Limit is 0.01 ppm.
All analytical work is subject to a systematic and rigorous
Quality Assurance-Quality Control (QA-QC). At least 5% of samples
are certified standards and the accuracy of the analysis is
confirmed to be acceptable from comparison of the recommended and
actual "standards" results. The remaining half core is stored on
site for future inspection and detailed logging, to provide
valuable information on mineralogy, structure, alteration patterns
and the controls on gold mineralization.
Cautionary Note to US Investors Concerning Estimates of
Inferred Mineral Resources
This press release uses the term "Inferred Mineral
Resources." The Company advises US investors that while this
term is recognized and required by NI 43-101,
the SEC does not recognize it. "Inferred Mineral
Resources" have a great amount of uncertainty as to their
existence, and great uncertainty as to their economic and legal
feasibility. It cannot be assumed that all or any part of
Inferred Mineral Resources will ever be upgraded to a higher
category. In accordance with Canadian rules, estimates of Inferred
Mineral Resources cannot form the basis of feasibility or other
economic studies. US investors are cautioned not to assume
that any part or all of the Inferred Mineral Resource exists, or is
economically or legally mineable.
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SOURCE Golden Star Resources Ltd.