The geophysical data available on the Greenland Mineral Resources Portal are both released company data and data acquired based on public funding (AEM and Aeromag surveys). The AEM Greenland 1994-1998 project, encompassed high resolution detailed multi-parameter surveys (electromagnetic, magnetic and partly radiometric) in the years 1994, 1995, 1996, 1997, and 1998 survey 1 and survey 2 producing a total of 75 000 line kilometres. The Aeromag projects, encompassed high resolution magnetic surveys conducted in 1992, 1995, 1996, 1997, 1998, 1999, 2001, 2012 and 2013 producing a total of more than 550 000 line kilometres. The projects were financed by the governments of Greenland and Denmark. More detailed information on the available geophysical date is given in Geology and Ore No. 22.

The dataset contains outlines of archived historical unpublished geological maps and sections of Greenland mostly created by GGU and GEUS but also some other institutes from 1916 onwards at various scales.

The digital terrain model of Greenland is constructed on the basis of GEUS's topographic datasets from the official geological maps of Greenland in scale ratio 1:100.000 and 1:500.000. The DEM is created using an interpolation method called Topo to Raster function in ArcGIS Desktop which is primarily supported by contour lines, coastlines and elevation points. The creation of the DEM was divided into in sub-areas based on the map sheet frames from the geological map of Greenland in 1:500.000 scale and assembled as a raster mosaic. The DEM was created with the spatial coordinate reference system WGS 1984 / UTM Zone 24N Complex with a resolution of a 100x100 meter grid. Based on the final DEM, a hillshade efect of the terrain has been constructed.

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.

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.

A series of Aster band ratios highlighting mineral distributions. Band ratio color composite images to distinguish variability of lithology in the area. Preprocessing of the Aster scenes encompasses atmospheric, radiometric and topographic corrections before masking non-outcrop pixels and generating the final mosaic. The calibrated radiance data is converted to apparent surface reflectance using a radiative transfer program, Atmospheric and Topographic Correction (ATCOR-3), in rugged terrain mode. The ATCOR rugged terrain mode utilizes a surface elevation model to adjust illumination levels. Calibration and adjusting the apparent surface reflectance values from the ATCOR-3 processing was not feasible due to lack of ground-based reflectance measurements.

Zircon age data as gathered from literature and GEUS samples

This map is the first national map showing the depth in meters to the uppermost redox interface in sediments of Quaternary age. The redox interface indicates the transition from the oxidized to the reduced geochemical environment in sediments. The redox interface was identified according to the colors of the sediments in 11,999 wells and is shown for 1x1 km grid-cells. For grid-cells with multiple site information, the depth to the redox interface is indicated by an average value. For grid-cells without any field information, the depth of the redox interface was established based on information about 1) geological setting, 2) morphology, 3) depths to redox boundaries at nearby field sites, 4) GEUS surface geology map, 5) topography, and 6) the pre-quaternary surface. The method for this first national redox-map and the data used is described in GEUS report no. 93 (2006) entitled Beregning af nitrat-reduktionsfaktorer for zonen mellem rodzonen og frem til vandløbet. Data og metode for 1.generationskortet (in Danish). The Redox map is also described in Vand og Jord (2011) 18: 37-39 (in Danish).

The dataset contains outlines of geological maps of Greenland printed and published by GGU and GEUS since 1957 at various scales. The dataset contains links to the GEUS Dataverse where each map has been assigned a DOI and can be downloaded in a resolution of 400dpi TIFF-images or pdf.

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.