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Theme Magazines and Fact Sheets
EXPLORATION AND MINING IN GREENLANDGreenland Mineral Resources
Fact Sheet No. 11
Download pdf-file go_fs11.pdf (~275 kbyte). Requires pdf-reader, Acrobat GSview or similar
Malmbjerg is a 1750 m. high mountain
located between two glaciers in a
remote area at 72° N lat. on the east
coast of Greenland. It hosts a rift-
related porphyry-molybdenum deposit
of the 'Climax type', discovered in
1954 during systematic mapping of
the Werner Bjerge complex by mem-
bers of the Danish East Greenland
Expeditions. The deposit enters a new
epoch, spurred by a dramatic rise in
the molybdenum price.
located between two glaciers in a
remote area at 72° N lat. on the east
coast of Greenland. It hosts a rift-
related porphyry-molybdenum deposit
of the 'Climax type', discovered in
1954 during systematic mapping of
the Werner Bjerge complex by mem-
bers of the Danish East Greenland
Expeditions. The deposit enters a new
epoch, spurred by a dramatic rise in
the molybdenum price.
Exploration history
Investigations in 1955 61 by the Danish
mining company Nordisk Mineselskab A/S,
and in 1962 by a Nordisk Mineselskab-
AMAX Inc. joint venture, included excavation of three
adits totalling 1329 m, from where 146 holes were
drilled some 22,000 m. Hereby an ore body of 119 Mt
grading 0.25% MoS
mining company Nordisk Mineselskab A/S,
and in 1962 by a Nordisk Mineselskab-
AMAX Inc. joint venture, included excavation of three
adits totalling 1329 m, from where 146 holes were
drilled some 22,000 m. Hereby an ore body of 119 Mt
grading 0.25% MoS
2
at a cut-off of 0.17% MoS
2
was
outlined. However, with a price at that time of US$
1.6/lb MoO
1.6/lb MoO
3
, mining was not economically feasible. In
1979, a new Nordisk Mineselskab/AMAX joint venture
made a 972 m drill hole to test for a deep ore body.
The result was negative. AMAX withdrew from East
Greenland, and the property remained with Nordisk
Mineselskab until its liquidation in 1991. Galahad Gold
Plc acquired the property in 2004.
made a 972 m drill hole to test for a deep ore body.
The result was negative. AMAX withdrew from East
Greenland, and the property remained with Nordisk
Mineselskab until its liquidation in 1991. Galahad Gold
Plc acquired the property in 2004.
Geology and mineralisation
The Malmbjerg porphyry molybdenum deposit is associ-
ated with a 25.7 Ma composite alkali granite stock
intruded in Carboniferous sandstones. It is part of the
intrusive Werner Bjerge alkaline complex belonging to
the Palaeogene East Greenland magmatic province. The
granite stock consists of three lithological units: Perthite
granite with a quartz-feldspar porphyry roof phase, a
heterogeneous porphyritic aplite, and porphyritic gran-
ites.
ated with a 25.7 Ma composite alkali granite stock
intruded in Carboniferous sandstones. It is part of the
intrusive Werner Bjerge alkaline complex belonging to
the Palaeogene East Greenland magmatic province. The
granite stock consists of three lithological units: Perthite
granite with a quartz-feldspar porphyry roof phase, a
heterogeneous porphyritic aplite, and porphyritic gran-
ites.
Molybdenite mineralisation occurs in a 700 x 700 x 150
m inverted bowel-shaped body mainly located in the
perthite granite and its porphyritic roof phase. Molyb-
denite occurs in veinlets ranging in thickness from hair-
line up to about 5 cm. The veinlets form a stock-work
of mutually offsetting veins. Pyrite occurs only as an
accessory mineral with an overall content of less than
one per cent. Furthermore, Mo-W-bearing greisen min-
eralisation occurs as flat-lying up to one metre thick
m inverted bowel-shaped body mainly located in the
perthite granite and its porphyritic roof phase. Molyb-
denite occurs in veinlets ranging in thickness from hair-
line up to about 5 cm. The veinlets form a stock-work
of mutually offsetting veins. Pyrite occurs only as an
accessory mineral with an overall content of less than
one per cent. Furthermore, Mo-W-bearing greisen min-
eralisation occurs as flat-lying up to one metre thick
veins in both the granite stock and in the sur-
rounding contact-metamorphosed sediments,
and minor base metal veins occur distally.
Pronounced alteration is associated with the mineralisa-
tion, both inside, below and above the stock-work
molybdenum accumulation.
rounding contact-metamorphosed sediments,
and minor base metal veins occur distally.
Pronounced alteration is associated with the mineralisa-
tion, both inside, below and above the stock-work
molybdenum accumulation.
New operators enter the scene
International Molybdenum Plc (InterMoly), who owns
100% of the Malmbjerg project, was established in late
2004 by Galahad Gold for the purpose of developing
two primary molybdenum licences in Greenland.
InterMoly subsequently engaged specialist consultants,
who appraised the results of the previous exploration
programmes at Malmbjerg and recommended further
work. They estimated that with a limited number of
confirmation drill holes, their resource estimates could
be upgraded to measured and indicated status, and
they designed a development programme at Malmbjerg
for 2005 to generate sufficient additional data to com-
plete a bankable feasibility study by early 2006.
100% of the Malmbjerg project, was established in late
2004 by Galahad Gold for the purpose of developing
two primary molybdenum licences in Greenland.
InterMoly subsequently engaged specialist consultants,
who appraised the results of the previous exploration
programmes at Malmbjerg and recommended further
work. They estimated that with a limited number of
confirmation drill holes, their resource estimates could
be upgraded to measured and indicated status, and
they designed a development programme at Malmbjerg
for 2005 to generate sufficient additional data to com-
plete a bankable feasibility study by early 2006.
All field activities for the project were completed over
the period April to September 2005. The programme
included 4,900 m underground confirmation drilling (31
holes) and 1,776 m channel sampling along the existing
adits. The drill campaign confirmed the results of previ-
ous drilling and filled in areas that were not included in
previous drill campaigns.
the period April to September 2005. The programme
included 4,900 m underground confirmation drilling (31
holes) and 1,776 m channel sampling along the existing
adits. The drill campaign confirmed the results of previ-
ous drilling and filled in areas that were not included in
previous drill campaigns.
The Malmbjerg porphyry
molybdenum deposit,
East Greenland
Malmbjerg, seen from the south, between
Schuchert Gletscher (left) and Arcturus
Gletscher (right).
Schuchert Gletscher (left) and Arcturus
Gletscher (right).
New resource estimate
A new mineral resource estimate for Malmbjerg
was announced by InterMoly on 17 November
2005:
· Measured and indicated resour-
was announced by InterMoly on 17 November
2005:
· Measured and indicated resour-
ces of 217 Mt at a grade of 0.20
% MoS
% MoS
2
with an additional
inferred resource of 12 Mt at a
grade of 0.15 % MoS
grade of 0.15 % MoS
2
, using a
0.12 % cut-off grade.
· Higher grade measured and indi-
cated resources of 33.8 Mt at a
grade of 0.28 % MoS
grade of 0.28 % MoS
2
, above a
cut-off grade of 0.25 %.
This resource estimate, which has
been prepared by Roscoe Postle
Associates Inc. compliant to
Canadian National Instrument 43-
101, incorporates historical data as
well as new data from the 2005
programme.
been prepared by Roscoe Postle
Associates Inc. compliant to
Canadian National Instrument 43-
101, incorporates historical data as
well as new data from the 2005
programme.
Plans for mining
Under its proposed base-case plan, InterMoly
envisages a 15,000 t/d underground operation,
producing around 14,600 t of MoS
envisages a 15,000 t/d underground operation,
producing around 14,600 t of MoS
2
concentrate
with an average grade of 50 % Mo annually for
15-20 years. The mining method is expected to be
large-scale underground block or panel caving, or
open stoping, and ore will be crushed under-
ground. The main mine portal will be located be-
low the mineralised body, and the company will
need to construct a 10 km underground access
tunnel to convey the crushed ore from the glacier-
bound deposit to the proposed plant site. A con-
ventional process plant based on grinding, flota-
tion and dewatering unit operations is proposed.
On exiting the plant, MoS
15-20 years. The mining method is expected to be
large-scale underground block or panel caving, or
open stoping, and ore will be crushed under-
ground. The main mine portal will be located be-
low the mineralised body, and the company will
need to construct a 10 km underground access
tunnel to convey the crushed ore from the glacier-
bound deposit to the proposed plant site. A con-
ventional process plant based on grinding, flota-
tion and dewatering unit operations is proposed.
On exiting the plant, MoS
2
concentrate will be
trucked to a proposed port facility on the banks of
the nearby Mesters Vig fjord.
the nearby Mesters Vig fjord.
Closing remarks
The projected capital costs for the 15,000 t/d
Malmbjerg project are estimated to be in the order
Malmbjerg project are estimated to be in the order
of US$ 605 mill. Operating costs are estimated at
US$ 15.7/t ore milled, and the company calculates
that the project breaks even at a MoO
US$ 15.7/t ore milled, and the company calculates
that the project breaks even at a MoO
3
price of
US$8/lb. InterMoly expects the higher-grade zone
tOForm the basis for initial mining of the deposit,
and the company estimates a long-term price pro-
jection for MoO
tOForm the basis for initial mining of the deposit,
and the company estimates a long-term price pro-
jection for MoO
3
of US$ 10-15/lb, compared with
the current market price of around US$ 30/lb. The
projected annual output represents around 4 % of
total world consumption of molybdenum.
projected annual output represents around 4 % of
total world consumption of molybdenum.
Geological Survey of Denmark
and Greenland (GEUS)
Øster Voldgade 10
DK-1350 Copenhagen K
Denmark
Tel: (+45) 38 14 20 00
Fax.: (+45) 38 14 20 50
E-mail: geus@geus.dk
Internet: www.geus.dk
Bureau of Minerals and Petroleum
(BMP)
Government of Greenland
P.O. Box 930
DK-3900 Nuuk
Greenland
Tel: (+299) 34 68 00
Fax.: (+299) 32 43 02
E-mail: bmp@gh.gl
Internet: www.bmp.gl
Author:
B. Thomassen
Editor: K.Secher
Layout: GEUS, Grafisk
© GEUS 2005
ISSN: 1602-8171
Key references
Bearth, P. 1959: On the alkali massif of the Werner Bjerge in East
Greenland. Meddelelser om Grønland
153
, 4, 62 pp.
Harpøt, O., Pedersen, J.L., Schønwandt, H.K. & Thomassen, B.
1986: The mineral occurrences of central East Greenland.
Meddelelser om Grønland Geoscience
17
, 138 pp.
Mining Journal (ed) 2005: InterMoly progresses Malmbjerg study,
Mining Journal, September 2, p 8 only.
Splitting drill cores in InterMoly's camp, 2005
WNW
ENE
Schuchert
Gletscher
Gletscher
Talus
Arcturius Adit
Porphyritic aplite
Perthite granite
Quartz - feldspar porphyry roof phase
of perthite granite
of perthite granite
Late Palaeozoic sediments
0.17% MoS2 cut-off
High silica zone
Biotite - magnetite - quartz zone
0
100 m
Vertical section through the Malmbjerg ore body. After Harpøth et al. 1986.
Last modified: January 17, 2006
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