GEUS Bulletin (Geological Survey of Denmark and Greenland)
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New evidence for possible generation of oil off south-western Greenland
No full textIn 2011, traces of bitumen in the 1160 Ma old Ilímaussaq intrusion in South Greenland have been examined in order to determine their origin. The investigation was prompted by the recent interest in hydrocarbon exploration off western Greenland, an interest expressed in the form of four new licences in the region (Christiansen 2011). The hydrocarbon potential in the region was realised after reinterpretation of seismic profiles across the Labrador Sea, and this indicates the presence of a sedimentary basin off south-western Greenland (Fig. 1; Chalmers & Pulvertaft 2001). However, the main problem in petroleum exploration off south-western Greenland is that no prolific marine source rocks have been demonstrated (Christiansen 2011). Therefore, any trace of hydrocarbons, however small that may help demonstrate the occurrence of source rocks in the region, deserves careful examination
From 3D mapping to 3D modelling: a case study from the Skaergaard intrusion, southern East Greenland
No full textThe powerful 3D mapping tool at the photogrammetry laboratory of the Geological Survey of Denmark and Greenland (GEUS) is ideal for collecting high-quality 3D geological data in remote and inaccessible areas with a high degree of exposure such as Greenland (Vosgerau et al. 2010). So far this 3D mapping tool has been used to visualise and extract very precise geological data from aerial and oblique photographs. In the study reported on here, the 3D mapping tool was used to generate data for 3D geological modelling. The Skaergaard intrusion (Fig. 1) is a well-known Eocene layered gabbro. The study of the intrusion has had great importance for the understanding of magmatic petrology, magma differentiation and fractional crystallisation since the early studies by Wager & Deer (1939). It was chosen for 3D modelling because it is well studied from a petrological point of view and because the shape of the magma chamber was previously modelled in a network of 2D cross sections (Nielsen 2004). In this paper, it is modelled for the first time in 3D using a detailed 1:20 000 scale geological map (McBirney 1989), 1:27 000 scale aerial photographs from 1973, data from drill holes and geophysical data
Testing of an automatic earthquake detection method on data from Station Nord, Greenland
No full textEarthquakes are continuously monitored by a global network of several thousand seismic stations equipped with highly sensitive digital seismometers. The Geological Survey of Denmark and Greenland (GEUS) takes part in it by operating five seismic stations in Denmark and 18 in Greenland, some of the latter in collaboration with international partners. There are two main ways of detecting earthquakes from digital recordings of seismometers: (1) by a manual review of the data by an expert in processing seismic earthquake signals and (2) by an automatic method that uses a computerised algorithm to analyse the recordings
Geological assessment of the East Greenland margin
No full textThe East Greenland margin consists of a number of sedimentary basins, platforms and structural highs (Figs 1, 2). Due to the challenges imposed by the Arctic climate, the region is in an early stage of exploration, and knowledge of the geology and petroleum potential of the margin is limited. However, the significant prospectivity of the conjugated European North Atlantic margin and the nature of the North-East Greenland onshore geology prompt for future offshore exploration. The US Geological Survey thus highlighted the North-East Greenland margin in their latest assessment of the Arctic region (Gautier et al. 2011). With a mean estimate of undiscovered recoverable oil, gas, and natural gas liquids of approximately 31 billion barrels of oil equivalents, the US Geological Survey ranked the North-East Greenland margin fourth in the entire Arctic region, only superseded by known producing petroleum provinces.
In preparation for the initial East Greenland licence rounds in 2012 and 2013 the Geological Survey of Denmark and Greenland gathers geological information on the margin necessary for the decision process of the Greenland authorities regarding exploration. Geophysical analyses complemented by well-data, onshore geology and information from the conjugated Atlantic margin form the backbone of the study. The East Greenland margin is covered by an open seismic grid supplemented by gravimetric and magnetic data. All existing 2D seismic, gravimetric and magnetic data are included in the current study. Most of the data are confi-dential. Restricted by the general confidential nature of the project, this paper aims to summarise the geology of the East Greenland margin based on the current and previous studies and to briefly assess some of the implications for the regional petroleum prospectivity
Review of Survey activities 2011
No full textThis Review of Survey activities presents a selection of 20 papers reflecting the wide spectrum of activities of the Geological Survey of Denmark and Greenland, from the microscopic to the plate-tectonic level. The Survey\u27s activities in Denmark and surrounding areas are illustrated by 11 articles covering petroleum geology, groundwater geology, geomorphology, marine geology, geothermal energy, seismology and monitoring of an underground gas storage. Activities in Greenland are covered by five papers dealing with mineral and petroleum exploration. Two other papers describe the Survey\u27s monitoring of the Greenland ice sheet and the testing of an automatic earthquake detection method on data from Station Nord, North Greenland. The Survey\u27s international activities are the subject of two papers: one dealing with petroleum geology in Vietnam, one with agrominerals in Tanzania
Natura 2000 habitat mapping in Kattegat, Denmark: an example from Læsø Trindel
No full textNatura 2000 is a network of nature protection areas established by the European Union under the Habitats Directive (European Union 1992). The aim is to assure long-term survival of the most valuable and endangered species and habitats in Europe. The network comprises special areas of conservation and protection designated by the member states under, respectively, the Habitats Directive and the Birds Directive. The establishment of the network of protected areas also fulfils a community obligation under the Convention of Biological Diversity of the United Nations
Detection of terrain changes in southern Denmark using persistent scatterer interferometry
No full textSince 1991, a number of European satellites have acquired data of the Earth’s surface for environmental monitoring. In general, a satellite will orbit the Earth in about 1½ hours and it takes 35 days before an ERS or ENVISAT satellite repeats radar scanning of the same position. For younger generations of satellites, such as RADARSAT and TERRA, the scanning repeat interval has decreased to 24 and 11 days, respectively, so that hundreds of radar scenes of the same place, produced over the past c. 20 years, are now available
Palaeogene deposits in North-East Greenland
No full textScattered occurrences of Palaeogene sediments are found in North-East Greenland, where they overlie unconformably Cretaceous sediments and are capped by Palaeogene basalts. These sediments have received little attention (Watt 1994), except for relatively recent studies (Nøhr-Hansen & Piasecki 2002; Jolley & Whitham 2004; Larsen et al. 2005; Heilmann- Clausen et al. 2008). As part of an ongoing petroleum geological study that focuses on the Jurassic–Cretaceous succession, the Palaeogene sediments were included to better constrain their age, depositional environment and relation to the basalts. Several localities were investigated on Wollaston Forland, Sabine Ø and Hold with Hope, a few of which are described here (Fig. 1)
Kennedy Channel and its geophysical lineaments: new evidence that the Wegener Fault is a myth
No full text2010, the year under review, marks the centennial of perhaps the most controversial structure in the Arctic: the Wegener Fault, the 1000-km long fracture that is supposed to underlie Nares Strait and define the north-western margin of an independent Greenland plate (Fig. 1). The seaway between Greenland and Ellesmere Island, Canada, was branded a megashear by Frank Taylor who, purely on physiographic expression, postulated massive Tertiary strike-slip (Taylor 1910). This revolutionary idea fittingly found a place in Alfred Wegener’s theory of continental drift and thereafter in plate-tectonic theory with Greenland drifting hundreds of kilometres from North America along what Tuzo Wilson subsequently dubbed the ‘Wegener Fault’ (Wilson 1963). Today, the concept lives on. In modern palaeogeography, Nares Strait is given a long multiphase dynamic history with collision of Greenland and Canada in the Palaeogene (Fig. 1). A freely drifting Greenland plate unconstrained by ties to North America is now part of conventional wisdom as related in textbooks, review articles and educational material available on the internet. Accordingly, the Wegener Fault is a standard feature in international compilations of world geology (e.g. UNESCO 2010; Fig. 2). Unfortunately, this 100-year acclamation from Taylor (1910) to UNESCO (2010) is fundamentally flawed: the rocks and their relationships at Nares Strait flatly contradict the existence of the structure
Shale gas investigations in Denmark: Lower Palaeozoic shales on Bornholm
No full textThe Cambrian to Lower Silurian succession in Denmark is mostly composed of organic-rich black shales that were deposited in an epicontinental sea during a period of high global sea level (Haq & Schutter 2008). The mid-Cambrian to early Ordovician Alum Shale was intensively studied in the 1980s for its source-rock properties (e.g. Buchardt et al. 1986). Recent attention has focused on its potential as an unconventional shale gas source (Energistyrelsen 2010). On southern Bornholm, many wells have been drilled through the Lower Palaeozoic succession because of its importance for groundwater exploitation. In western Denmark, only the deep exploration wells Slagelse-1 and Terne-1 have penetrated the Alum Shale, and knowledge of the unit west of Bornholm is thus very limited (Fig. 1)