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Theme Magazines and Fact Sheets
EXPLORATION AND MINING IN GREENLANDGreenland Mineral Resources
Fact Sheet No. 16
Download pdf-file go_fs16.pdf (~0.7 mb). Requires pdf-reader, Acrobat GSview or similar
Sedimentary and chemical deposited iron forma-
tions (BIF), from which almost all iron is obtained,
are one of the great iron sources in the world, and
in Greenland. Here, deposits related to banded
iron formations (BIF), mostly so-called Algoma
type, are typical for Archaean greenstone belts
formed in continental rifts or at continental mar-
gins.
tions (BIF), from which almost all iron is obtained,
are one of the great iron sources in the world, and
in Greenland. Here, deposits related to banded
iron formations (BIF), mostly so-called Algoma
type, are typical for Archaean greenstone belts
formed in continental rifts or at continental mar-
gins.
Regional distribution and age
of Greenland BIF
of Greenland BIF
In Greenland such deposits are located at Isukasia (~3.8
Ga) in southern West Greenland, at Itilliarsuk (~2.85 Ga)
in central West Greenland, and in North West Greenland
along the Melville Bugt BIF (~2.7 Ga). The deposits are
all characterised by their large size, approaching gigantic
dimensions.
Ga) in southern West Greenland, at Itilliarsuk (~2.85 Ga)
in central West Greenland, and in North West Greenland
along the Melville Bugt BIF (~2.7 Ga). The deposits are
all characterised by their large size, approaching gigantic
dimensions.
The Isukasia BIF
The Isua Greenstone Belt (IGB), hosting the Isukasia de -
posit about 150 km north-east of Nuuk, is an up to 4
km wide and about 40 km long crescent with enclaves
of greenstones, a few hundred metres wide and up to
several kilometres long. Large ultrabasic bodies with
lesser amount of mafic volcanic rocks and banded iron
formation dominate these greenstone belts. BIF occurs
mostly as layered quartz magnetite rocks (oxide facies),
but silicate facies bands of alternating grunerite and
magnetite are also common. Carbonate facies iron for-
mation consisting of alternating bands of siderite and
magnetite are rare. In oxide facies iron formation, small
amounts of actinolite and pyrite occur. Silicate facies
rocks with grunerite also contain pyrrhotite, chalcopyrite
and locally small amounts of gold. In the easternmost
part of the IGB a major body of oxide facies iron forma-
tion occurs. Two thirds of the body is concealed under
the Inland Ice. The Isukasia (Isua) iron deposit is, with an
age of around 3.8 Ga, probably the oldest banded iron
formation in the world.
posit about 150 km north-east of Nuuk, is an up to 4
km wide and about 40 km long crescent with enclaves
of greenstones, a few hundred metres wide and up to
several kilometres long. Large ultrabasic bodies with
lesser amount of mafic volcanic rocks and banded iron
formation dominate these greenstone belts. BIF occurs
mostly as layered quartz magnetite rocks (oxide facies),
but silicate facies bands of alternating grunerite and
magnetite are also common. Carbonate facies iron for-
mation consisting of alternating bands of siderite and
magnetite are rare. In oxide facies iron formation, small
amounts of actinolite and pyrite occur. Silicate facies
rocks with grunerite also contain pyrrhotite, chalcopyrite
and locally small amounts of gold. In the easternmost
part of the IGB a major body of oxide facies iron forma-
tion occurs. Two thirds of the body is concealed under
the Inland Ice. The Isukasia (Isua) iron deposit is, with an
age of around 3.8 Ga, probably the oldest banded iron
formation in the world.
The Isukasia structure and deposit were first discovered
by the Danish company Kryolitselskabet Øresund A/S
(`The Cryolite Company') during field activity in 1962,
and an iron resource of around 2 billion tons of ore aver-
aging 32.9% Fe was estimated. A large number of dia-
mond drillholes were made, some of them through the
inland ice. Twenty years later, Rio Tinto took up a con-
cession and had two campaigns of drilling. Rio Tinto
aimed at finding high grade hematite lump ore, but was
not satisfied with the results. In January 2006, IMC
Group Consultants Ltd (IMC) estimated JORC indicated-
inferred resources of 955 Mt averaging 34% Fe, includ-
by the Danish company Kryolitselskabet Øresund A/S
(`The Cryolite Company') during field activity in 1962,
and an iron resource of around 2 billion tons of ore aver-
aging 32.9% Fe was estimated. A large number of dia-
mond drillholes were made, some of them through the
inland ice. Twenty years later, Rio Tinto took up a con-
cession and had two campaigns of drilling. Rio Tinto
aimed at finding high grade hematite lump ore, but was
not satisfied with the results. In January 2006, IMC
Group Consultants Ltd (IMC) estimated JORC indicated-
inferred resources of 955 Mt averaging 34% Fe, includ-
ing an indicated-inferred open
pit resource of 181 Mt aver -
aging 33.43% Fe, and the
London Mining Plc. took over
the concession of the area.
pit resource of 181 Mt aver -
aging 33.43% Fe, and the
London Mining Plc. took over
the concession of the area.
The Itilliarsuk BIF
The geotectonic setting of the
Archaean supracrustal rocks of
the area south of Nuussuaq
Peninsula in central West
Greenland represents a rift or
continental margin environment with more metasedi-
ments intercalated in the volcanic sequences than in the
island arc setting further south. The thickest succession
of supra crustal rocks occurs in the Itilliarsuk area. The
supra crustal sequence is at least 2.5 km thick and a
banded iron formation deposit occurs 200 m above an
often visible `rust zone' within the supra crustals. The
banded iron formation is an approximately 200 m wide
sequence of 210 cm magnetite-rich cherty bands alter-
nating with quartz-mica schists. A gradual transition
zone between the iron formation and the adjacent rocks
in the se quence is characterised by a garnet-hornblende-
magnetite bed. The iron-rich beds gradually become
poorer in magnetite and richer in garnet and horn-
blende. Cyclic repetition occurs between the magnetite-
bearing bed, and the occurrence of garnet and horn-
blende in distinct beds can be traced over 500 m along
strike. This indicates that the transition from iron oxide
Archaean supracrustal rocks of
the area south of Nuussuaq
Peninsula in central West
Greenland represents a rift or
continental margin environment with more metasedi-
ments intercalated in the volcanic sequences than in the
island arc setting further south. The thickest succession
of supra crustal rocks occurs in the Itilliarsuk area. The
supra crustal sequence is at least 2.5 km thick and a
banded iron formation deposit occurs 200 m above an
often visible `rust zone' within the supra crustals. The
banded iron formation is an approximately 200 m wide
sequence of 210 cm magnetite-rich cherty bands alter-
nating with quartz-mica schists. A gradual transition
zone between the iron formation and the adjacent rocks
in the se quence is characterised by a garnet-hornblende-
magnetite bed. The iron-rich beds gradually become
poorer in magnetite and richer in garnet and horn-
blende. Cyclic repetition occurs between the magnetite-
bearing bed, and the occurrence of garnet and horn-
blende in distinct beds can be traced over 500 m along
strike. This indicates that the transition from iron oxide
Banded iron formation' (BIF) deposits
12 m thick BIF horizon in a sequence of pelitic gneiss (rusty
brown) and amphibolit (dark), south of Pituffik, North-West
Greenland.
brown) and amphibolit (dark), south of Pituffik, North-West
Greenland.
Isukasia
Itilliarsuk
Pituffik (Thule)
La
u
g
e
K
o
c
h
h
K
ys
t
to iron silicates reflects a primary chemical grada-
tion in the sediment.
tion in the sediment.
The Cryolite Company initiated exploration in the
Itilliarsuk area. NunaMinerals A/S later carried out
exploration in the area, mainly targeted for gold.
The company estimated that the iron-mineralised
part was covering an area of 130 x 1000 m and
that it has a resource of 150200 Mt of ore grading
20% Fe. Renewed interest from other companies in
the ore potential of the area has in 2007 resulted in
new applications for exploration licen ces.
Itilliarsuk area. NunaMinerals A/S later carried out
exploration in the area, mainly targeted for gold.
The company estimated that the iron-mineralised
part was covering an area of 130 x 1000 m and
that it has a resource of 150200 Mt of ore grading
20% Fe. Renewed interest from other companies in
the ore potential of the area has in 2007 resulted in
new applications for exploration licen ces.
Iron occurrences in the Qaanaaq
(Thule) region
(Thule) region
The Qaanaaq (Thule) region of North-West Green -
land exposes a high-grade Archaean Palaeo pro -
terozoic crystalline shield overlain by the intracra-
tonic mainly Mesoproterozoic Thule Basin, which
extends across Baffin Bay into Canada.
land exposes a high-grade Archaean Palaeo pro -
terozoic crystalline shield overlain by the intracra-
tonic mainly Mesoproterozoic Thule Basin, which
extends across Baffin Bay into Canada.
The southern part of the Qaanaaq region hosts a
Neoarchaean iron province which spatially is the
largest in Greenland. It forms a WNWESE-trending
belt, traceable for more than 400 km from Kap
Seddon in the south-east throughout the Lauge
Koch Kyst to Wolstenholme Ø and Carey Øer. This
belt correlates with the iron-rich rocks on northern
Baffin Island, Canada. Iron in the form of magnetite
and hematite occurs both as quartz-banded iron
formation (BIF), massive lenses and layers, and dis-
seminated, mainly in pelitic and mafic schists of the
Lauge Koch Kyst supracrustal complex. BIF occurs
in units of varying thickness, from less than a metre
and up to 40 m, where iron concentrations typically
are 3035%. Furthermore, oxide facies BIF as well
as silicate facies BIF with minor iron sulphides occur
scattered in the northern part of the Qaanaaq
region.
Neoarchaean iron province which spatially is the
largest in Greenland. It forms a WNWESE-trending
belt, traceable for more than 400 km from Kap
Seddon in the south-east throughout the Lauge
Koch Kyst to Wolstenholme Ø and Carey Øer. This
belt correlates with the iron-rich rocks on northern
Baffin Island, Canada. Iron in the form of magnetite
and hematite occurs both as quartz-banded iron
formation (BIF), massive lenses and layers, and dis-
seminated, mainly in pelitic and mafic schists of the
Lauge Koch Kyst supracrustal complex. BIF occurs
in units of varying thickness, from less than a metre
and up to 40 m, where iron concentrations typically
are 3035%. Furthermore, oxide facies BIF as well
as silicate facies BIF with minor iron sulphides occur
scattered in the northern part of the Qaanaaq
region.
No systematic mineral exploration has been carried
out in the North-West Greenland iron province,
which is mainly known from the regional geological
mapping carried out by the Greenland Geological
Survey 197180. It is worth noticing that a similar
occurrence in the northern Baffin Island of Nunavut
in Canada, the Mary River iron ore project, has
been explored recently and initiate mine construc-
tion is planned to take place in 2010.
out in the North-West Greenland iron province,
which is mainly known from the regional geological
mapping carried out by the Greenland Geological
Survey 197180. It is worth noticing that a similar
occurrence in the northern Baffin Island of Nunavut
in Canada, the Mary River iron ore project, has
been explored recently and initiate mine construc-
tion is planned to take place in 2010.
Concluding remarks
The potential for iron resources of the BIF type in
Greenland is promising, taken into consideration
that a number of deposits are large and that they
are located in accessible tracts. Recent exploration
on more levels has demonstrated an increased
interest in the occurrences.
Greenland is promising, taken into consideration
that a number of deposits are large and that they
are located in accessible tracts. Recent exploration
on more levels has demonstrated an increased
interest in the occurrences.
Key references
Appel, P.W.U., Garde, A.A., Jørgensen, M.S., Moberg, E.D.,
Rasmussen, T.M., Schjøt, F. & Steenfelt, A. 2003:
Preliminary evaluation of the economic potential of the green-
stone belts in the Nuuk region. Danmarks og Grønlands
Geologiske Undersøgelse Rapport
2003/94
, 147 pp.
Dawes, P.R. 2006:
Explanatory notes to the Geological map of
Greenland, 1:500 000, Thule, Sheet 5. Geological Survey of
Denmark and Greenland Map Series
2
, 97 pp. + map.
Stendal, H. & Schønwandt, H.K. 2003:
Precambrian supracrustal
rocks and mineral occurrences, Northeast Disko Bugt.
Danmarks og Grønlands Geologiske Undersøgelse Rapport
2003/24
, 57 pp.
Stendal, H. & Stensgaard, B.M. (eds) 2006
: Geology and min-
eral resources in Greenland and northeastern North America.
Reports, abstracts and presentations, Kangerlussuaq work-
shop, October 2005. Danmarks og Grønlands Geologiske
Undersøgelse Rapport
2006/6
, 119 pp. + 1 CD-ROM.
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
H. Stendal, B. Thomassen, GEUS
Editor
K. Secher, GEUS
Layout
Henrik Klinge Pedersen, GEUS
Photographs
GEUS unless otherwise stated
Printed
January 2008 © GEUS
Printers
Schultz Grafisk
ISSN
1602-8171
Close-up of folded banded quartz-magnetite ore in a
1 m outcrop at Isukasia, southern West Greenland.
1 m outcrop at Isukasia, southern West Greenland.
Boulder of banded hematite ore (23 x 53
cm), found along the ice margin at Isukasia,
southern West Greenland.
cm), found along the ice margin at Isukasia,
southern West Greenland.
