GEUS Bulletin (Geological Survey of Denmark and Greenland)
Not a member yet
521 research outputs found
Sort by
Potential for permanent geological storage of CO2 in China: the COACH project
No full textThe challenge of climate change demands reduction in global CO2 mission. Carbon dioxide capture and storage (CCS) technology can be used to trap and store carbon dioxide gas emitted by coal-burning plants and this can reduce the world’s total CO2 emission by about one quarter by 2050 (IEA 2008, 2009; IPCC 2005). Experience from the storage sites of Sleipner in the Norwegian North Sea, Salah in Algeria, Nagaoka in Japan, Frio in USA and other sites shows that geological structures can safely accommodate CO2 produced and captured from large CO2 point sources. CCS is regarded as a technology that will make power generation from coal sustainable, based on cost-effective CO2 capture, transport and safe geological storage of the released CO2
Late Quaternary geology of a potential wind-farm area in the Kattegat, southern Scandinavia
No full textFollowing the proposal of the offshore Anholt wind-farm project with an energy capacity of 400 megawatt in the Kattegat, southern Scandinavia, an evaluation of the geotechnical properties of the subsurface of the area is required. As a first step to map the seabed geology the Geological Survey of Denmark and Greenland (GEUS) conducted a geophysical survey (Leth et al. 2009) which, together with cone penetration tests and data from boreholes, lead to a greater understanding of the geological architecture and development of the 144 km2 survey area (Figs 1, 2)
Radon content in Danish till deposits: relationship with redox conditions and age
No full textRadon (222Rn) is a radioactive, noble insoluble gas with a half-life of 3.8 days. It belongs to the uranium (238U) decay chain where radon is formed from radium (226Ra). Uranium and radium are built into mineral structures or are, for example, adsorbed on the surface of clay minerals, limonite or organic material. When radon is formed by radioactive decay from radium, parts of it enter the pores of rocks and soils and are transported by diffusive or advective forces in the pores. The transport rate depends on the permeability and water content in the pores (Nazaroff 1992)
The mineral resource assessment project, South-East Greenland: year one
No full textSouth-East Greenland between 62°N and 67°N is one of the lesser known regions in Greenland, having seen only limited geological investigations and only few detailed ones, with the Skjoldungen alkaline igneous province as a notable exception (Nielsen & Rosing 1990). Systematically collected geoscientific data are scarce; however, such data are essential as a basis for geological models and for evaluation of the mineral potential. In order to open up the region for exploration, the Greenland Bureau of Minerals and Petroleum financed a two-year, mainly geochemical programme for 2009 and 2010, which is an initial part of a five to six year project that involves subsequent geophysical surveys, a geological programme and a full-scale resource assessment of the region. The primary objective of the initial geochemical programme is to collect sediment samples for analysis of chemistry and indicator minerals. Supplementary to this, surface water for chemistry is collected and radiometric spectra of representative lithologies are measured. Geological reconnaissance field work focussing on selected key areas is also carried out
Lithostratigraphy of the Upper Oligocene – Miocene succession of Denmark
No full textThis paper presents a revised lithostratigraphic scheme for the uppermost Upper Oligocene – Miocene succession of Denmark. The marine Oligocene Brejning Clay Member is upgraded to formation status and includes the Sydklint Member and the Øksenrade Member (new). The shallow marine and deltaic deposits of mainly Early Miocene age are included in the Ribe Group (new) while the fully marine Middle and Upper Miocene clay-rich deposits are referred to the Måde Group (new). The Ribe Group is subdivided into 6 formations: the Vejle Fjord Formation is revised and includes the Skansebakke Member, the Billund Formation (new) includes the Addit and Hvidbjerg Members (new), the Klintinghoved Formation is redefined formally and includes the Koldingfjord Member (new), the Bastrup Formation (new) includes the Resen Member (new), the Vandel Member is a new member in the Arnum Formation (revised), the Odderup Formation is redefined and includes the Stauning Member (new) and the coalbearing Fasterholt Member. The Måde Group is subdivided into the Hodde, Ørnhøj (new), Gram and Marbæk (new) Formations. Subdivision of the Upper Oligocene – Miocene succession into two groups, the Ribe and Måde Groups, is compatible with the North Sea lithostratigraphic framework where they correlate with the upper part of the Hordaland Group and the Nordland Group, respectively.
The revised lithostratigraphic framework correlated in three dimensions provides rigorous constraints on the palaeogeographic interpretation of the Late Oligocene – Miocene period. Three major deltaic units (Billund, Bastrup and Odderup Formations) prograded from the north and north-east into the North Sea Basin during the Early – early Middle Miocene. Delta progradation was punctuated by deposition of marine clay and silt associated with minor transgressive events (Vejle Fjord, Klintinghoved and Arnum Formations). During the Middle–Late Miocene, marine depositional conditions dominated (Hodde, Ørnhøj and Gram Formations). A fourth and final progadational event (Marbæk Formation) commenced in the latest Tortonian heralding the emergence of present-day Denmark (including the North Sea sector)
Characterisation of host rocks and hydrothermal alteration of the Qussuk gold occurrence, southern West Greenland
No full textGold exploration in the Godthåbsfjord region has been carried out since the early 1990s, and the region is now recognised as a gold province. Several prospects have been drilled and Storø is the most advanced project in the Færingehavn terrane. The gold occurrence at Storø is 2635 Ma old according to 207Pb/206Pb age determinations of metamorphic zircons associated with auriferous arsenopyrite (Nutman et al. 2007). Qussuk is located in the Akia terrane (Fig. 1), separated from the Færingehavn terrane in the south by the SW–NE-trending Ivinnguit fault. The Ivinnguit and Ataneq faults are spatially associated with several hydrothermal gold occurrences. From north to south these are: Isua, Storø, Bjørneøen, Sadelø, Store Malene and Qilanngaarsuit (Fig. 1; Appel et al. 2005; Kolb et al. 2009). The Qussuk prospect 20–25 km north of the Ataneq fault is 20 km long, 2–3 km wide, and divided from north to south into the ‘Swan N’, ‘Swan’ and ‘Plateau’ areas (Fig. 1)
Application of airborne hyperspectral data to mineral exploration in North-East Greenland
No full textAn airborne hyperspectral survey was organised by the Geological Survey of Denmark and Greenland (GEUS) and carried out in 2000 to test the use of spectral analysis in mineral exploration under Arctic conditions. The hyperspectral data were acquired by using the HyMap imaging system consisting of sensors that collect reflected solar radiation in 126 bands covering the 440–2500 nm wavelength range (Bedini & Tukiainen 2008). The spatial resolution was 4 × 4 m (Tukiainen 2001). Eight sites underlain by Caledonian or post-Caledonian rocks with known mineral occurrences (Fig. 1) were tested. The project was financially supported by the Greenland Bureau of Minerals and Petroleum and the data were analysed by GEUS. Here we provide a summary of the results
Bathymetry, shallow seismic profiling and sediment coring in Sermilik near Helheimgletscher, South-East Greenland
No full textThe Greenland ice sheet is one of the most significant contributors to the rising global sea level with a contribution of 0.5 mm per year (Rignot & Kanagaratnam 2006). Evidence is emerging that rising temperatures of subsurface ocean currents play a vital role in the recent acceleration of large fast flowing glaciers such as Jakobshavn Isbræ in West Greenland (Holland et al. 2008) and Helheimgletscher in South-East Greenland (Straneo et al. 2010). Important questions are whether these incursions of warmer water are part of a recurrent phenomenon and indeed exactly how they influence the glaciers. The Geocenter Denmark project SEDIMICE (Linking sediments with ice-sheet response and glacier retreat in Greenland) investigates past ice fluctuations in the Helheimgletscher region in South-East Greenland with regard to magnitude, possible causes and effects. One of the main tasks in this project is to analyse sedimentary deposits in the main fjord Sermilik (Fig. 1), which is influenced by the tidally affected Helheimgletscher that has a short floating tongue. By combining sediment studies with modern climate studies we aim to extrapolate meteorological data back in time
Review of Survey activities 2009
No full text2009 was a favourable year for the Geological Survey of Denmark and Greenland (GEUS) with focus on research, often in international collaboration. Many new projects have been initiated and many completed. In 2009, Copenhagen hosted COP15, and GEUS’ involvement in the preparation for this event focussed on climate changes, reducing consumption of fossil fuels and CO2 emissions
Distribution and grain size of sand in the Miocene wave-dominated Billund delta, Denmark
No full textThe distribution of sand in deltas depends on the delta regime: wave, fluvial or tidal-dominated delta (Orton & Reading 1993; Bhattacharya & Giosan 2003). During the Early Miocene, three delta complexes built out from the Fennoscandian Shield into the eastern North Sea Basin (Rasmussen 2004). The oldest delta complex, which is informally named the Billund delta, is located in Jylland (Fig. 1). This delta complex was mainly wave-dominated (Rasmussen & Dybkjær 2005; Hansen & Rasmussen 2008; Rasmussen 2009a). Recently, it has been demonstrated that in modern wave-dominated delta environments sand mostly accumulates on the updrift portion of the delta (Fig. 2) whereas alternating mud and sand, e.g. barrier-lagoon complexes, occupy the downdrift portion of the delta system (Bhattacharya & Giosan 2003). The current study shows that most of the sand in the submarine part of the Miocene wave-dominated Billund delta (mainly lower shoreface and delta slope sand) was deposited downdrift to the delta front and thus differs from the foreshore and uppermost shoreface accumulation found in recent delta complexes