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.

Zircon age data as gathered from literature and GEUS samples

Exploration companies are obliged to report their activities to the Ministry of Minerals and Resources (MMR). Now reports are delivered in digital format, but were previously delivered in paper, to the Geological Survey of Denmark and Greenland (GEUS). They are scanned and released reports are available under Reports. Digital restoration The data that the reports hold is thus available, but stored as images in scanned pdf?s. The geochemical data of 4 reports (Allen & Harris, 1980; Coppard et al., 1992; Harris et al., 1992 and Pearson & Joudrie, 1995) have been digitized. I.e. the reports have be optically characterised and the sample locations georeferenced. The matching of the sample locations and geochemically referenced samples does not always match. Meaning that a sample that has coordinate may not have geochemical results, and a sample with geochemical measurements might not have coordinate. The reporting of the analytical facilities and precision is sparse. Detection limits, analytical uncertainty and reliability are generally not reported. Analytical methods and analysed grain fractions of sediment samples also not reported. When all these issues have been listed, it should be noted that errors may occur. From the digital restoration of scanned paper to optically characterisation of the scanned text and numbers errors may be introduced. The user is cautioned to these issues. Upload to data base To make the data available on the web, upload to GEUS sample data base is required. To fit into the sample data base, some adjustments had to be made. Sample names modified, collector created etc., resulting in modified sample names, relative to the ones used in the reports. The reports from which the samples occur in are not mentioned in the data base. Hence the four reports and links to them are listed below:

The geological maps of Denmark on a scale of 1:400,000 focus on the Danish basin and its geological structures. The map includes areas that extend from the geological age 'Basis Kalk' and the Kalk Gruppen. The 'Basis Kalk' map shows the depth in metres, where 'Basis Kalk' denotes the area that forms the basis for all layers younger than the Early Cretaceous. Over the majority of the mapped area, this surface is level with the base of the Kalk Group, but where the limestone is eroded away, the surface is equal to the base of the Quaternary. The depth to 'Basis Kalk' is calculated as the depth to the base of the deposits younger than Denmark plus the thickness of the Kalk group. The map is published in DGU Map Series no. 29 from 1991, where further information about the mapping can be obtained.

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.

Historical mineral exploration and exploitation licences in Greenland. The data are converted from the WFS that the ministery of mineral resources (MMR) in Greenland provides. Links are provided in the online resources.

Ujarassiorit is a mineral hunt competition open to residents of Greenland. Participants can submit rock samples from Greenland to the Ministry of Minerals Ressources (MMR) for evaluation and may be selected for a prize.

Cross sections and map profiles from different geological maps and publications.

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 geologist and will be augmented through more information forthcoming through GEUS and company activities. Only data released to the public will be available to external users over the internet.

GEUS' Earthquake Portal provides information on all recorded earthquakes in Greenland. The data are extracted from GEUS' earthquake database and are updated daily. As a result, the timing, locations, and magnitudes of events may change as new data are added and existing events are revised. Continuous quality control is carried out, aiming to identify and remove explosions – typically related to military exercises or the removal of old munitions. Therefore, the list may change over time, and some uncertainty may be associated with the determination of epicentres and depths. The portal displays information for each earthquake, including the time of occurrence (year, month, day, hour, minute, second) in Greenwich Mean Time (GMT), the geographical location and depth of the epicentre, and the local magnitude measured on the Richter scale. Earthquake data can be exported from the portal according to the defined zoom level and map extent.