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.

Non-confidential mineral exploration licence reports and other geoscientific reports have been recieved by Greenlandic authorities and subsequently send to GEUS in accordance with the Mineral Resources Act of Greenland (1 January 2010) and associated regulations. This dataset allows to search in the database using alphanumeric and geographic search criteria and to access report metadata. It is also possible to download the actual report as a PDF file.

Protected areas 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.

The gravity compilation is based on data stored in the national/Nordic gravity data base at the DTU Space. This data base contains for Greenland data surveyed by DTU Space on behalf of the geodetic survey authorities “Danish Agency for Data Supply and Efficiency” (SDFE) and its predecessor agencies “National Survey and Cadastre” (KMS) and the Geodetic Institute (GI), with some data dating back to the 1950’s. Older data have been rectified into modern gravity datums (absolute gravimetry and IGSN71). The national data contains both surface, airborne and marine data, mainly in the coastal ice-free regions and offshore (Forsberg et al, 2001, Kenyon et al, 2008). Airborne, marine and land data from a number of external data sources are also included in the data base after a QC process, including high-level airborne data from the GAP91/92 campaigns (Brozena et al, 1993) and recent data from NASA OIB (MacGregor et al., 2021) and OMG projects (Fenty et al., 2016). Marine data in the Baffin Bay and Davis Strait and land data from the Geodetic Survey Division, Canada (Veronneau 2010, pers.comm.), and a number of other marine and land data from a large set of contributors have also been included in the compilation, including marine data from Alfred Wegener Institute (Germany), land and marine data from Orkustofnun (Iceland), and a number of released commercial data sources. In areas void of gravity data, satellite-derived altimetry data have been used as fill-in (DTU 15, Andersen et al. 2017). The compiled grids have been based on public domain and some proprietary data sources, and has been computed for the area 58-85°N, 78-7°W on a 0.02°x 0.05° grid, using rigorous downward continuation of airborne data to the terrain surface, with terrain corrections from a detailed digital terrain and ice sheet surface model, and long-wavelength satellite gravity data from GRACE and GOCE satellites (Forsberg and Olesen, 2010). The data are available as a free-air (Faye) anomaly grid as well as a derived terrain-corrected Bouguer anomaly grid (land and ice sheet areas only), computed in GRS80 with density 2.67 g/cm3. The ice sheet Bouguer anomaly data are derived using the ice sheet thickness model of Bamber et al., 2013. The free-air gravity grid (v1) have also have been used as the primary background data also for the latest geoid models of Greenland (GGEOID16).

The Geological Survey of Denmark and Greenland has previously conducted sampling campaigns of heavy mineral concentrate in Greenland. The sampling methods are described according to their sampling years below. Unfortunately, not all the samples have reported as the campaigns in have not been undertaken on regional scale and therefore fallen under smaller projects or sampled under projects that have had other objects, and not all elements were considered relevant in the reports, translating to that metadata concerning the analyses are missing. All together there are geochemical analyses of 725 heavy mineral concentrate samples. The samples that are mentioned in reports below, are 319 in number, and do not comprise all heavy minerals samples collected the specified years. Samples collected in un-mentioned campaigns do occur in the full list. Use of data that is not mentioned here, needs caution and the quality should be weighed against other data. Years 1982-1986 A regional sampling campaign was conducted between 1982 and 1986, these samples are described in Appel 1989. These samples comprise the analysis batch numbers 10, 36 and 55. Numbers 10, 36 are analysed at Activation Laboratories and 55 analysed at Bondar-Clegg and Co. Ltd., both in Canada. In this campaign 210 samples were collected and are all sampled in the area around Nuuk. Sampling procedure: In the field: The coastal areas were accessed by boat while inland areas were accessed by helicopter. Four litres of coarse gravel and sand were collected and sieved through a 6 mesh of brass. The fines (c. 10 %) was panned and inspected in ultraviolet light and the scheelite grains counted. In the laboratory: The samples were dried and separated by bromoform, the heavy material was weighed and the scheelite grains counted again. A small splitter separated c. 0.5 gram of each sample for analysis of W, Mo, Pb, Cu, Cr, Co, V, Mn, Zr, Ni and Fe. During the years the sampling programme as well as the analysis methods changed. In 1983 the four litres were added up to five. In 1985 the material increased to 5-6 litres (or 10 kg). In 1986 a plastic sieve with 1 mm holes used and filled three times (5-8 kg) for each sample, the volume of fines was measured. C. 10 gram of each sample was analysed by Bondar-Clegg for (Sc, Cr, Fe, Co, Ni, As, Se, Rb, Mo, Ag, Cd, Sb, CS, BA, La, Eu, Tb, Yb, Hf, Ta, W, Ir, Au, Th and U) analyses. The reader should note that the analyses below detection limit is given as "0" (zero) and not analysed as "-1" for the samples collected in this campaign (year 1982-1986, i.e. batch numbers 10, 35 and 55). Year 1991 In 1991, 106 streams were sampled for heavy mineral concentrate, in the southern part of the Nuuk area, between 62°30?N and 64°N. Sample procedure was as follows: 5-10 litres of detrital material, < 5 cm, were collected, from 2-5 sub-localities in the stream bed. Wet sieving split the sample in less-than and bigger-than 0.5 mm, and the coarser fraction inspected for economic minerals. The fine fraction was heavy minerals concentrate was produced using a rotary panning device "goldhound" (see Erfurt et al., 1992 for reference). The heavy mineral concentrate was shipped to Denmark and dried and further spilt for analytical purposes. Activation Laboratories, Canada, analysed the samples for 35 elements including gold, with INAA and ICP-ES. Analyses batches are numbered 10 and 36. Unique samples number 103 for these two batches. In additional batch 41, has analysed Pb, Cu, Ni and Zn. Year 2004 The analyses batch no. 193 and 194 have been described in GEUS report 2004/42, and were sampled in 2003 in the Qaanaaq region in North-West Greenland. Six samples were collected in this campaign and sieving of 1.0 mm material on site and a pre-concentrate by panning of the fine fraction. In Copenhagen minerals with > 2.8 g/cm3 density was produced by heavy liquid separation. The rest The remaining 406 samples (analyses batch numbers: 10, 15, 21, 35, 36, 41, 55, 165, 166, 193, 194, 374, 375, 376, 1014, 1015, 1016, 1017, 1029, 1030, 1051, 1052, 1077 and 1078) have been analysed in addition to the laboratories mentioned above, at Risø National Laboratory in Denmark. As reports have not been available for writing up these analyses, the description is limited to the analyses. Chances are, however, that sampling procedures are similar to the descriptions above. The analyses below detection limits of the remaining 406 unique samples have not been consistent, but are presented as "0" or as negative values and elements that have not been measured as "0" or empty cells.

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.

Nationwide geophysical database for environmental and raw material data, also known as GERDA (GEophysical Relational DAtabase). The database contains various types of geophysics, including geoelectrics, electromagnetics, borehole logs and seismic. All data is freely available for download on the GEUS website. The database is updated continuously.

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 soil samples 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. Five samples are used in the Geochemical Atlas of Stream sediment samples of South-West Greenland (Steenfelt, 1999). 204 samples from North Greenland have been used in the Geochemical Atlas of Stream sediment samples for North Greenland (Thrane 2011). In addition soil samples were collected in the SEGMENT project (Kolb et al. 2016)

Basic information about the location of on- and offshore drillholes from Greenland for scientific research, mineral and oil and gas exploration. If available, a link to a report or summary sheet is specified that is the original source of information. The data is from 1948 through to 2019 and subject to change as new information becomes available from scientific reports, press releases and company documents.