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.

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 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 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 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.

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 Atlas samples of N Greenland package are described in Thrane et al 2011. This package builds on samples collected over a period from 1978 to 1999, holding old and newly acquired data. Some of the old samples have been reanalysed and together they have been quality controlled and compared. There are 2,644 unique samples in this package (65 of these samples are located under Soil samples). The geochemical analyses that are presented are above detection limit and readings below have been filtered out. Sampling The sampling density is not consistent throughout the covered area, and varies from 1 sample per 30 to 50 km2 to scarce and irregular in other areas. The regional geochemical surveys undertaken in North Greenland, follows the procedure for stream sediment sampling in Steenfelt, 1999. Thrane et al 2011, give more information sampling campaigns in the area. The sample consists of 500 g sediment collected from stream bed and banks into paper bags. In the filed the samples were dried and sent to Copenhagen for further drying and screening. Analyses was made on a split fraction < 0.1 mm size fraction.

The dataset contains rock sample geochemistry collected from 1957 to 2007 in south to central west Greenland analyzed with different methods that have been published in 3 reports.

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.

Zircon age data as gathered from literature and GEUS samples