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.

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.

Zircon age data as gathered from literature and GEUS samples

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.

The place names data set is from the book 'Northern East Greenland's research history and place names' by A.K. Higgins, which GEUS published in 2010, with associated maps which have now been converted to web GIS format. Via free text search, you can find the place names with their explanations and their location on the map.

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 of mostly around 1 sample per 30 km2 but up to 1 sample per 5 km2 in parts of South Greenland. 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, selection of the most reliable analytical data and elimination of analytical bias (calibration), the final consistent dataset, named batch 2005, contains data from 7122 samples analysed for up to 43 elements (see Steenfelt 1999, 2001b for details on data selection and calibration). In batch 2005, values below lower detection limit are indicated by the digit 0. Sample location Before 1997, 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 1997 onwards, GPS was used to determine sample positions.

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.

Samples of surface material, i.e. stream sediment, soil, and scree have been collected over large parts of Greenland from 1974 onwards mainly as part of mineral exploration programmes and more broadly for geochemical mapping by means of stream sediment (Steenfelt 1999, 2001). Following various sample preparation procedures, like drying and screening, making concentrates of heavy minerals from stream sediment or soil, certain fractions of the samples have been chemically analysed at diverse laboratories where a range of analytical methods were applied as they became available over the years. The present dataset contains the analytical data from stream sediment as they were received from the laboratories together with administrative data, including sample location and grain-size fraction analysed. Many samples have been analysed at more than one laboratory and by more than one method and the analytical data for each sample and grain size fraction are listed lab by lab and method by method in the same row. The majority of the samples were collected and analysed before year 2000. More recent data from South-East and North Greenland have been added (Kolb et al 2016).

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.

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).