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.

This view presents data selected from the geochemical mapping of North Greenland that are relevant for an evaluation of the potential for zinc mineralisation: CaO, K2O, Ba, Cu, Sr, Zn. The data represent the most reliable analytical values from 2469 stream sediment and 204 soil samples collected and analysed over a period from 1978 to 1999 plus a large number of reanalyses in 2011. The compiled data have been quality controlled and calibrated to eliminate bias between methods and time of analysis as described in Thrane et al., 2011. In the present dataset, all values below lower detection limit are indicated by the digit 0. Sampling The regional geochemical surveys undertaken in North Greenland follows the procedure for stream sediment sampling given in Steenfelt, 1999. Thrane et al., 2011 give more information on sampling campaigns in the area. The sample consists of 500 g sediment collected into paper bags from stream bed and banks, alternatively soil from areas devoid of streams. The sampling density is not consistent throughout the covered area and varies from regular with 1 sample per 30 to 50 km2 to scarce and irregular in other areas. Analyses were made on screened < 0.1 mm or <0.075 mm grain size fractions.

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.

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.

Zircon age data as gathered from literature and GEUS samples

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.

The Raw stream sediment samples dataset is data as they have been delivered from the laboratories, i.e. values below detection limit often spelled as negative but zero may also apply. The data are not controlled by a geologist. In addition, they may not have been reported.

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.

The area in South-East Greenland between 62°30’N and 66°30’N was targeted for its mineralisation potential through data collection and renewed mapping during the collaborative ‘SEGMENT’ project (2009-2014) between the Geological Survey of Denmark and Greenland (GEUS) and the Bureau of Minerals and Petroleum (BMP, now Ministry of Mineral Resources, MMR). The main aims of the ‘SEGMENT’ project included: • Compiling a regional stream sediment geochemical and till indicator mineral survey; • Compiling a regional aeromagnetic survey of South-East Greenland; • Conduct geological field investigations in order to characterise the main lithology and as the basis for geological research, including petrology, structural geology, geochemistry and geochronology; • Evaluate economic geology and mineral potential through field investigations, using geological parameter in order to be able to predict possible mineralisation; • Revise the existing 1:500 000 geological map of South-East Greenland; and • Integrated data interpretation to describe and provide a geological model for the geological evolution of South-East Greenland and assess the mineral of potential of the region. The details behind the data collection and mapping efforts under the ‘SEGMENT’ project are summarized in the GEUS report by Kolb et al. (2016) which provides an overview of the geology and the lithological units within the mapping area between 62°N and 66°30’N.