The regional-scale gamma spectrometry data are associated with two collaboration projects involving the Geological Survey of Greenland (GGU) and the Danish Atomic Energy Commission’s Research Establishment. The projects' objectives were to outline areas with an elevated uranium potential in two regions of Greenland: The airborne radiometric surveys in southern and central West Greenland in 1975/76 and the SYDURAN project in South Greenland in 1979-1982. To acquire the data, four-channel gamma ray spectrometers were mounted upon an aircraft (1975/76 surveys) and a helicopter (SYDURAN project). The vehicles flew along shoreline and valley contour lines at low average terrain clearances of 100 and 50 m respectively. The data were recorded without GPS systems, and so positioning was estimated when known landmarks were passed. This means that the dataset is sparse and inhomogeneous, and the spatial accuracy remains low. The gamma-spectrometer had been calibrated at a pad facility at Risø, which enabled the conversion of recorded counts per second into simulated concentrations of radioactive components in the surface of the overflown terrain. Large parts of the data (surveys from 1975/76) were originally stored on magnetic tapes and data were transferred to datafiles in 2003 to make them digital accessible. Most data were retrieved and are now available as ASCII files.

The gravity compilation is based on data stored in the national/Nordic gravity data base at the DTU Space. This data base contains for Greenland data surveyed by DTU Space on behalf of the geodetic survey authorities “Danish Agency for Data Supply and Efficiency” (SDFE) and its predecessor agencies “National Survey and Cadastre” (KMS) and the Geodetic Institute (GI), with some data dating back to the 1950’s. Older data have been rectified into modern gravity datums (absolute gravimetry and IGSN71). The national data contains both surface, airborne and marine data, mainly in the coastal ice-free regions and offshore (Forsberg et al, 2001, Kenyon et al, 2008). Airborne, marine and land data from a number of external data sources are also included in the data base after a QC process, including high-level airborne data from the GAP91/92 campaigns (Brozena et al, 1993) and recent data from NASA OIB (MacGregor et al., 2021) and OMG projects (Fenty et al., 2016). Marine data in the Baffin Bay and Davis Strait and land data from the Geodetic Survey Division, Canada (Veronneau 2010, pers.comm.), and a number of other marine and land data from a large set of contributors have also been included in the compilation, including marine data from Alfred Wegener Institute (Germany), land and marine data from Orkustofnun (Iceland), and a number of released commercial data sources. In areas void of gravity data, satellite-derived altimetry data have been used as fill-in (DTU 15, Andersen et al. 2017). The compiled grids have been based on public domain and some proprietary data sources, and has been computed for the area 58-85°N, 78-7°W on a 0.02°x 0.05° grid, using rigorous downward continuation of airborne data to the terrain surface, with terrain corrections from a detailed digital terrain and ice sheet surface model, and long-wavelength satellite gravity data from GRACE and GOCE satellites (Forsberg and Olesen, 2010). The data are available as a free-air (Faye) anomaly grid as well as a derived terrain-corrected Bouguer anomaly grid (land and ice sheet areas only), computed in GRS80 with density 2.67 g/cm3. The ice sheet Bouguer anomaly data are derived using the ice sheet thickness model of Bamber et al., 2013. The free-air gravity grid (v1) have also have been used as the primary background data also for the latest geoid models of Greenland (GGEOID16).

In the present database there are 1269 unique samples. Soil samples have been collected in areas without river beds. Preferably stream samples have been collected, but areas where temporarily no stream beds are present, soil samples have been collected as an alternative for geochemical mapping purpose. Five samples in this package are originally from the report Compilation of data sets for a geochemical Atlas (Steenfelt, 1999). These samples have been analysed by "UNKNOWN" methods at "UNKNOWN" laboratories. In fact these samples have been calibrated and corrected for analytical bias, see Steenfelt 1999, for further information.

The regional aeromagnetic datasets were acquired from the Alfred Wegener Institute for Polar and Marine Research (AWI), Bremerhaven, Germany, in four field campaigns along the coastal regions of Northeast Greenland from 1993-1996. The line spacing ranges both in inline and crossline direction from 10-40 km and the levels range up to 3700 m. Presented maps are based on data reprocessed by GEUS.

Uniform aerial photographic coverage of Greenland was achieved in 1978-1987 at 1: 150 000 scale by Mark Hurd Aerial Surveys, Inc., Minneapolis, Minnesota, U.S.A., for the Danish Geodetic Institute [Weidick, 1995]. The photography is now administered by the Danish Geodata Agency, see also http://eng.gst.dk/maps-topography/greenland/aerial-photos-of-greenland. The camera used for these black and white photographs was a Wild RC 10 with a super wide angle lens (focal length = 88 cm). The airplane used by Mark Hurd was a Gates Lear Jet 25C. By setting the flying height to app. 14 km the image scale of 1:150 000 was achieved [Bengtsson & Jørgensen, 1980]. In an attempt to avoid blind areas, caused by the precipitous mountainsides in combination with the use of a super wide angle lens, the photographs were taken with a length-lap of 80%, and a side-lap of 40%. In the subsequent use of the photography (for aerotriangulation, mapping and scanning) generally only every other image were used (as you will see from the photo number shown on this web-page). The photo center coordinates are from the aerotriangulation by the Danish Geodata Agency. Please contact GST for the high resolution photos.

The dataset contains outlines of archived historical unpublished geological maps and sections of Greenland mostly created by GGU and GEUS but also some other institutes from 1916 onwards at various scales.

This view presents data from stream sediment geochemical mapping of West and South Greenland (Steenfelt, 2001a). Stream sediment samples were collected from 1979 to 1998 with as even coverage as possible from low-order streams and with a sampling density between 1 sample per 5 km2 and 1 sample per 50 km2, mostly around 1 sample per 30 km2. With few exceptions, the 0.1 mm grain size fractions of 500-g samples were analysed for major and trace elements by two or three methods. After careful quality control and elimination of bias between analytical values determined by different methods or at different times (calibration), the most reliable analytical data were selected as the final consistent dataset, containing data from 7122 samples analysed for up to 43 elements (see Steenfelt 1999, 2001b for details on data selection and calibration). Major element oxides and volatiles are determined by X-Ray Fluorescence Spectrometry (XRF) and loss on ignition, respectively. Loss on ignition mostly reflects the amount of organic material in stream sediment samples. As the aim is to show the regional variation in the chemistry of the minerogenic component of the stream sediment, volatiles are not included in the major element composition which is recalculated as volatile-free oxides. Instead, volatiles are listed in a separate column for documentation. Locally, high loss on ignition may be caused by high contents of carbonate in the stream sediment of streams draining rare occurrences of marble or carbonatites. For detailed or more accurate studies, the CO2 concentrations of the stream sediment samples should be measured, or the amount of carbonate minerals estimated by microscopy. Trace element data are from methods determining total concentrations (XRF, Instrumental Neutron Activation, Delayed Neutron Counting). The quality of the trace element data varies (see Steenfelt 1999, 2001b) In the present dataset, all values below lower detection limit are indicated by the digit 0. Sample location Before 1993, sample sites were originally marked on topographic maps at the scale 1:100,000 and their positions were later digitised and later again corrected, when a new topographic reference was introduced around year 2000. From 1993 onwards, GPS was used to determine sample positions.

The dataset contains information on more than 280.000 shallow boreholes, comprising informatiion on borehole-related data such as geological desciptions, the borehole construction, soundings etc.The dataset is part of the Jupiter Database, which is GEUS ' nationwide database for groundwater, drinking water, raw materials, environmental and geotechnical data. The database is the single public data base in the field and is included in the National Environmental Portal. The database is publicly available and is updated on an ongoing basis.

The map is based on selected seismic data up to 2001. The map shows the structural conditions at depth for the 'Top Kalk' surface, from the central to the eastern part of the Danish North Sea. 'Top Kalk' denotes the surface which forms the basis of the Tertiary deposits (except Denmark). The map is described in GEUS Bulletin No. 13. 2007.

Intrusions and magmatic complexes are central, when it comes to an assessment of the economic geological potential of a region. There are many of these in Greenland, and only a few of them have been examined in detail for their economic potential. In Nielsen (2002), tertiary intrusions and complexes in East Greenland were described, and later on information on intrusions and magmatic complexes in all of Greenland, were modelled based on the same methodology. The information has been compiled by GEUS geologists.