Entire Greenland

Geological environments and related Mineral Occurrences

Regional data compilations

West Greenland (66°-70°15') - the Palaeoproterozoic Nagssugtoqidian, Rinkian Orogen and the adjacent North Atlantic Craton

South Greenland south of 62ºN – the Palaeoproterozoic Ketilidian Orogen and the southernmost part of the North Atlantic Craton

Background themes for Entire Greenland Geological Environments and related Mineral Occurrences

The main geological environments in Greenland and their mineral resources have been described in Stendal et al. (2005).
Greenland can be divided into four main geological environments, infracrustal regions, supracrustal regions, magmatic provinces,
and sedimentary basins. Within these various geological environments characteristic, mineral deposits are presented. Four maps
of the individual geological environments are produced as well as a combined map including all the geological environments.

Mineral occurrence data

In 2005, the Geological Survey of Denmark and Greenland (GEUS) completed a joint project with the Bureau of Minerals and
Petroleum, Greenland, about main geological environments in Greenland and their mineral resources. The project involved
definition of the four main geological environments and for each environment, the selection and description of characteristic
mineral occurrences (Stendal et al. 2005).

Not many mineral occurrences within infracrustal environments are recorded in Greenland but three types can be mentioned: Gold
in gneiss, nickel and copper in mafic intrusions, and olivine in ultramafic rocks.

The supracrustal rocks include metasedimentary rocks, metavolcanics and banded magnetite-quartzite formation. The mafic
metavolcanic rocks are worth special attention because of their significant mineral potential, not the least for gold and base metal
deposits. These deposits are often related to greenstone belts with mafic volcanics or mixed mafic volcanic and sedimentary rocks.
Besides gold, other mineral occurrences are iron, copper, chromium, tungsten, as well as industrial minerals.

The mineral occurrences in the magmatic environment are the porphyry system related to Palaeogene alkalic intrusions in East
Greenland and associated vein systems with gold and silver; veins related to the Caledonian granite and the Julianehåb batholith,
which carries tungsten, arsenic, antimony, and gold; the alkaline intrusions in the Gardar province have niobium, tantalum,
zirconium, rare earth elements, and cryolite; carbonatite with niobium, tantalum, apatite and kimberlite-lamproite with diamonds are
located within the Kangerlussuaq region of West Greenland.

Many of the globally known mineral occurrence types in sedimentary environments also occur in Greenland. Examples are copper in
sandstones in Neoproterozoic and Triassic clastic sediments; lead and zinc in shale/carbonate sequences are widespread in the
sedimentary basins; a fossil placer represents a placer deposit and celestite an evaporite deposit; lead-zinc veins in sediments
occur in the Mesters Vig area including the now closed Blyklippen Pb-Zn mine, East Greenland.

Preliminary geological map 1:2 500 000

The base for drawing the geological environment map is the digital geological map at 1:2 500 000 scale based on the geological
map of Greenland published by Escher & Pulvertaft (1995) and described by Henriksen et al. (2000).

Suitable sample sites with an even distribution have been selected by stereoscopic inspection of aerial photographs prior to the
fieldwork. Second or third order streams with catchments areas less than 20 km2 are preferred. Two man teams supported by
helicopter undertook the actual sampling. In certain low-relief landscapes, proper streams were absent, and samples have been
collected from sediment on the shores of small lakes instead. At each sampling site, c. 500 g of stream sediment was collected in a
paper bag and a short site description made. The stream sediment sample was composed of subsamples from three to fifteen
sediment deposits along 10 to 50 m of the stream course. Samples were preferably collected among stones and gravel on the
streambed, with the consideration that the resultant sample should contain a sufficient amount of fine material. Deficiency of suitable
stream sediment has been met in streams with high water flow or streams in low-relief, vegetated terrain. In such places, a sample
was collected from sediment trapped in moss or other vegetation between stones or along the banks.

Until 1992, the sample locations were noted on aerial photographs, transferred to topographic maps at scale 1:250 000, and then
digitised. From 1992 onwards, the Global Positioning System (GPS) was used. As streams and lakes are variably offset from their
location in the old topographic base (scale 1:250 000) all stream sediment sample sites have been adjusted to a new topographic
in scale 1:500 000 base by manually moving the sample location to the proper new stream position.

Sample preparation and analysis: Sample bags were provisionally dried in the field before they were wrapped, packed and shipped
to GEUS, Copenhagen. Samples were then oven-dried at 60°C and dry-sieved using two polyethylene screens. The fraction above 1
mm grain size was discarded, the 0.1 to 1 mm size fraction stored, and the <0.1 mm size fraction was submitted for analysis.

The record of analytical treatment of samples throughout the long period of surveying is given in Steenfelt (1999). This report also
gives a short description of each of the laboratories and analytical methods employed.

Quality control: The low-density stream sediment data presented here are extracted from the quality controlled and calibrated data
used to produce a geochemical atlas of West and South Greenland (Steenfelt 2001). Steenfelt (1999) describes the methods used
for selection of valid data and correction of analytical bias.

Theme presentation: Au, As and Cu distributions are illustrated by coloured grid images using software (Oasis Montaj) provided by
Geosoft Inc. The gridding was performed with the kriging method using a power model, a grid cell size of 5x5 km and a blanking
distance of 5 km. The square outline of individual grid cells is seen at the margin of the grid image only. The software has a default
interpolation procedure for smoothing boundaries between differently coloured cells similar to contouring. The colour scale giving
class intervals for grid colours is constructed individually for each element and is guided by percentiles of the frequency distribution.
The distribution of As, Sb and Rb is illustrated by combined grids – as a triplot grid.

Additional images of other geochemical elements and sample locations are available in Schjøth, F. & Steenfelt, A. (2004).Analytical
data can be acquired from GEUS at cost.

Background data themes for South Greenland south of 62°

A selection of geo-themes is supplied as backdrops for the mineralisation data. The data images are available in Schjøth et al. (2000)
and a review of new digital data sets concerning the mineral resource potential of South Greenland is described in Steenfelt et al. (2000).
The reports can be ordered at costs from GEUS.

Mineral occurrence data

The presentation of mineral occurrences in South Greenland south of 62^oN included is based on published information, non-
confidential company reports, and fieldwork during the SUPRASYD project (1992–1996). All identified mineral occurrences, which
might be of interest from either an economic or a genetic point of view, have been reviewed. Coordinates for the mineral occurrence
localities have been extracted from the Greenland Mineral Occurrence database (GREENMIN). In some cases, especially for the
uranium mineral occurrences, the coordinates of the localities have been updated according to GEUS sample data base
(GEUSGREEN).

The descriptions vary in size and detail because the available information is inhomogeneous. In general, important and major occurrences
( e.g. Nalunaq from which many company reports and published papers exist) have more information available than small occurrences.

Geochemistry

Stream sediment geochemistry

• Stream sediment (fine fraction): Sample locations were originally digitised using former KMS maps at the scale 1:100000. The old
  sample positions are individually transferred to their correct position on the new reference map. The resulting sample lo

  The projection parameters of the base map and for all spatial data described in the following sub-sections, are:

  Geodetic reference:                                 WGS84

  UTM-zone:                                                23 (i.e. the central meridian is 45° West)

  False Easting:                                          500 000

  The copyright to G250 Vector belongs to KMS

  Topographic base: G/250 Vector, Copyright Kort & Matrikelstyrelsen, 2001

    cations are as accurate as the original positions.

Geochemical surveys

(1) SYDURAN (South Greenland Uranium Exploration project). This project was conducted by the Geological Survey of Greenland
(GGU) in collaboration with Risø National Laboratory (Armour-Brown et al. 1982). For geochemical purposes c. 2300 samples were
collected with an average sampling density of 5-6 samples per km² in South Greenland, covering up to Sermiligaarsuk (61°30¢N) on
the west coast, and up to Lindenow Fjord (60°30¢N) on the east coast, i. e. within the area covered by aeroradiometry. The < 0.1 mm
grain size fraction was analysed at Risø National Laboratory, Denmark, for U by delayed neutron counting (DNC), and for major and
trace elements by isotope excited energy dispersive X-ray fluorescence spectrometry (XRF; Kunzendorf & Løvborg 1981). The results
were reported as geochemical maps by Armour-Brown et al. (1982) and by Olesen (1984). At a later stage (1990) the samples were
analysed at Activation Laboratories Ltd. for 34 major and trace elements by instrumental neutron activation (INA) analysis. These
analyses were financed by Nunaoil A/S. Later (1990-1992), the remaining sample material was analysed at GGU for major element
oxides and 5 trace elements by X-ray fluorescence spectrometry (XRF) on fused glass discs using sodium tetraborate as flux. Na₂O
and Cu were determined by atomic absorption spectrometry (AAS).

(2) SUPRASYD. As part of GGU's reconnaissance geochemical mapping pro­gramme (Steenfelt 1993) and the 'Suprasyd' programme
(Nielsen et al. 1993) a total of 142 stream sediment samples were collected in 1992 in the area along the east coast of South
Greenland from Lindenow Fjord to Otte Rud Øer (62° N). Due to steep topog­raphy and extensive ice cover in this area the sample
spacing is very irregular. An average figure for the sam­ple density is in the order of 1 sample per 50 km². The < 0.1 mm grain size
fractions of the samples were ana­lysed at Activation Laboratories Ltd. for major element oxides by XRF on fused discs using lithium
tetraborate as flux, for 14 trace elements by XRF on pressed powder tablets, and for 35 major and trace elements by INA. The results
are reported in Steenfelt et al.  (1992). 126 data points from this survey are included in the present data set.

( Trace elements 1 to 3 group layers are made because of differences in the numbers of the sample locations that are analysed:

T 3) The Paamiut region. This area was sampled in 1993 in the course of GGU's reconnaissance geochemical mapping programme
(Steenfelt 1993; 1994). The <0.1 mm grain size fractions of the stream sediment samples were analysed at GGU by XRF using fused
glass discs for major elements (except Na₂O) and 5 trace elements. Na₂O and Cu were determined by AAS. The samples were further
analysed at Activation Laboratories Ltd for 35 major and trace elements by INA and for 14 trace elements by XRF using pressed
powder tablets. The results are reported in Steenfelt et al.  (1994).  57 sample points from this survey lie within the present map area.

The stream sediment data are displayed in following layers and group layers:

• Stream sediment locations
• Coast mask
• Major elements
• Trace elements 1
• Trace elements 2
• Trace elements 3

* Major elements calculated as volatile-free percentages

Trace element values in ppm except Au, which are in ppb

¹XRF: X-ray fluorescence spectrometry, INA: Instrumental neutron activation analysis, I+X: combined XRF and INA, DNC+I: Delayed
neutron counting and INA

Preliminary geological map 1:500 000

The 1:500 000 scale geological map published by the Geological Survey of Greenland (Allaart 1975) was chosen as basis for the
digital map. The map was scanned and then vectorised. It was a complication in this process that the topographical base of the
existing map (Lambert conformal conic projection) was different from the improved topographical base in UTM projection (G250
Vector). Thus, all geological units had to be individually fitted to match the new map base.

Geophysic

The digital terrain model (DTM)

The aeromagnetic survey flown in project Aeromag 1995 (Thorning & Stemp 1997) provided accurate GPS data for the aircraft.
Combining these data with radar altitude data also recorded by the survey aircraft, an approximate Digital Elevation Model (DEM) was
calculated for the region. Though not very accurate, this can give a useful view of the topography. Therefore, the geophysical contractor
flying the Aeromag 1995 survey (Sander Geophysics Limited, Ottawa), was asked to produce a DEM sampled into a 100 by 100
metres grid. The DEM is limited to the Aeromag 1995 survey area and does not cover the NW corner of the map.

Airborne electromagnetics (EM)

Airborne electromagnetic data are also available from project AEM Greenland 1996, see above and Stemp (1997). The results are
presented in two anomaly maps, as apparent resistivity from controlled source measurements and as anomalies of measured VLF
signals. The data are presented in a 50 metres by 50 metres grid in the form of images.

The survey was flown with the Aerodat Inc. helicopter EM system, with a five frequency vertical co-axial and horizontal co-planar loop at
a nominal height of 30 metres above ground. The co-axial systems used frequencies of 920 Hz and 4 600 Hz and the co-planar
system used frequencies of 515 Hz (or 860 Hz), 4 200 Hz and 33 000 Hz. The nominal height of the VLF-sensors was 45 metres above
ground level. The flight line separations and directions are as described above for the magnetic data.

Gravity

Gravity data from the database maintained by the KMS are presented as Bouguer and free-air anomalies (GRS80 standard and
IGSN71 system) in separate geo-referenced TIF-files. The irregularly distributed data points have been transformed into a grid with a
sampling distance of 2 500 metres. Gridding of the data was done using a minimum total curvature algorithm.

Mosaic of Landsat TM scenes

South Greenland is fairly well covered by Landsat TM data. However, because of the unfavourable location of South Greenland in
relation to the Landsat ground receiving stations, the availability of good quality Landsat TM data for geological purposes has been
sporadic, especially in the eastern part of the area, until the launch of the Landsat TM 7 satellite. The satellite image map is a mosaic
of seven Landsat TM scenes. Landsat TM bands 4 (red), 3 (green), and 2 (blue) have been used for the colour composite included as
a view.

Magnetic surveys

Several magnetic anomaly maps from different sources are included. The most comprehensive magnetic data set is from the
regional, airborne geophysics projects Aeromag 1995 and Aeromag 1996 covering the coastal region from the Inland Ice to the ocean
(see Thorning & Stemp 1996, 1997). Both surveys were flown with fixed-wing aircraft at a gentle drape at a nominal height of 300
metres above ground level and with 500 metres between survey lines. The line direction was 30° NW for the Aeromag 1995 survey and
37° NW for the Aeromag 1996 survey. Orthogonal control lines were flown with a separation of 5 000 metres for both surveys. Only the
southern part of the Aeromag 1996 survey is within South Greenland. The Aeromag 1995 survey was flown by Sander Geophysics
Limited and the Aeromag 1996 survey was flown by Geoterrex-Dighem Limited.

The data from the two surveys have been merged into a uniform data set and are presented as magnetic total field anomalies and
calculated first vertical derivative anomalies in grid form. The grids were calculated at 100 metres cell sizes and are presented as
images in the form of geo-referenced TIF-files.

In project AEM Greenland 1996, a helicopter borne multi-sensor geophysical survey (Stemp 1997) included magnetic measurements
in five detailed areas in the north-western corner of the South Greenland project area. Aerodat Inc. flew the survey with their helicopter
EM system. The data were collected at a nominal ground clearance of 45 metres for the magnetic sensor, along flight lines spaced
200 metres apart and with orthogonal control lines at intervals of 2 000 metres. The sampling interval of 0.1 of a second between
measurements corresponds to a sampling distance of four metres. The flight line directions are different for the five survey blocks:

• Sermiligaarsuk North: 30° NW
• Midternæs: 30° NW
• Grænseland: E-W
• Sioralik South: E-W
• Arsuk Ø: N-S

Airborne radiometrics

Radiometric data are available from project Syduran and from project AEM Greenland 1996. The data include measurements from
helicopter of the radiation from uranium, thorium, potassium and total count.

An Exploranium GR820 – 256 channel gamma ray spectrometer (16.8 litre NaI crystal) was used for the measurements in the AEM
Greenland 1996 project. The radiometric anomaly maps are presented as grids with 50 metres sampling distance. An Akima spline
technique was used for the interpolation. The data were collected at a nominal height of 60 metres and with line separations and
directions as described above for the magnetic data.