Mantle xenoliths from Tertiary lavas and dykes on Ubekendt Ejland, West Greenland

1998 ◽  
pp. 152-154
Author(s):  
Stefan Bernstein ◽  
C. Kent Brooks
Keyword(s):  
Field Work ◽  
Mantle Xenoliths ◽  
Alkaline Basalt ◽  
Basalt Flow ◽  
Volcanic Province ◽  
East Greenland ◽  
Original Series ◽  
West Greenland ◽  
Ultramafic Xenoliths ◽  
Extensive Collection

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Bernstein, S., & Brooks, C. K. (1998). Mantle xenoliths from Tertiary lavas and dykes on Ubekendt Ejland, West Greenland. Geology of Greenland Survey Bulletin, 180, 152-154. https://doi.org/10.34194/ggub.v180.5099 _______________ Mantle xenoliths were found in Tertiary alkaline (basanitic) lavas on Ubekendt Ejland in West Greenland in the mid 1970s by J.G. Larsen. Microprobe analyses of olivine, pyroxene and spinel in two mantle xenoliths, suggested that the xenoliths on Ubekendt Ejland are highly depleted and have high modal olivine contents, and low modal orthopyroxene and clinopyroxene (Larsen 1982). In this respect the mantle xenoliths from Ubekendt Ejland are very similar to the spinel harzburgites from Wiedemann Fjord, in the Tertiary volcanic province of East Greenland (Brooks & Rucklidge 1973; Bernstein et al. 1998). Larsen (1981) also reported dykes containing mantle nodules and a varied suite of cumulates and megacrysts, one of which has subsequently been dated to 34.1 ± 0.2 Ma (Storey et al. 1998) The basalt flow that carries the xenoliths is from what is defined as the Erqua Formation which occurs at the top of the lava succession in western Ubekendt Ejland (Fig. 1; Drever & Game 1948; Larsen 1977a, b). The basalts have not been dated, but are younger than 52.5 Ma, which is the date obtained for the underlying formation (Storey et al. 1998). During July 1997, we spent three weeks collecting xenoliths and prospecting for xenolith-bearing dykes in the Uummannaq district of central West Greenland. The field work resulted in an extensive collection of xenoliths from an alkaline basalt flow described by Larsen (1977a, b), as well as the discovery of a dyke carrying a large number of ultramafic xenoliths of various origins. 

Pingos at Nioghalvfjerdsfjorden, eastern North Greenland

1998 ◽  
pp. 159-162 ◽  
Author(s):  
Ole Bennike
Keyword(s):  
North America ◽  
Open System ◽  
Closed System ◽  
Field Work ◽  
Frozen Ground ◽  
East Greenland ◽  
Original Series ◽  
West Greenland ◽  
System Type ◽  
North Greenland

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Bennike, O. (1998). Pingos at Nioghalvfjerdsfjorden, eastern North Greenland. Geology of Greenland Survey Bulletin, 180, 159-162. https://doi.org/10.34194/ggub.v180.5101 _______________ Pingos are isolated, conical mounds up to 50 m high with a core of ice covered by silt, sand or gravel. They are formed in regions where the ground is permanently frozen. Two types of pingo are distinguished, a closed-system and an open-system (Washburn 1979; Pissart 1988). The closed-system type is found on flat plains, whereas open-system pingos are found on valley floors. Open-system pingos grow by artesian pressure (Müller 1959; Washburn 1979). Water from higher altitudes migrates within or below the permanently frozen ground and becomes trapped within the permafrost and freezes to form a lens or core of ice. Active pingos have been reported from Svalbard, Russia, Alaska, Canada and Greenland (Washburn 1979), and fossil pingos from Pleistocene periglacial terrains have been reported from Europe and North America (De Gans 1988). In Greenland, most pingos have been reported from both East and West Greenland. In East Greenland pingos have been described from the area between 71°30′ and 74°30′N (Fig. 1). In West Greenland most pingos occur between 70° and 72°N. In addition, a pingo and some pingo-like forms have been described from North Greenland (Bennike 1983). All pingos in Greenland are located in valleys, usually on outwash plains. During field work in 1997 one fairly impressive pingo and several small pingos or pingo-like forms were observed at c. 79°30′N in eastern North Greenland. These are the northernmost pingos recorded from eastern Greenland, and the aim of this note is to document and describe these forms. The observations add to our knowledge about the distribution of pingos in Greenland, and a map showing the distribution of pingos in Greenland is presented as Fig. 1.

Upernavik 98: reconnaissance mineral exploration in North-West Greenland

1999 ◽  
pp. 39-45 ◽  
Author(s):  
Bjørn Thomassen ◽  
Johannes Kyed ◽  
Agnete Steenfelt ◽  
Tapani Tukiainen
Keyword(s):  
Mineral Exploration ◽  
Mining Industry ◽  
Field Work ◽  
Geological Survey ◽  
Original Series ◽  
West Greenland ◽  
North West ◽  
One Year

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Thomassen, B., Kyed, J., Steenfelt, A., & Tukiainen, T. (1999). Upernavik 98: reconnaissance mineral exploration in North-West Greenland. Geology of Greenland Survey Bulletin, 183, 39-45. https://doi.org/10.34194/ggub.v183.5203 _______________ The Upernavik 98 project is a one-year project aimed at the acquisition of information on mineral occurrences and potential in North-West Greenland between Upernavik and Kap Seddon, i.e. from 72°30′ to 75°30′N (Fig. 1A). A similar project, Karrat 97, was carried out in 1997 in the Uummannaq region 70°30′–72°30′N (Steenfelt et al. 1998a). Both are joint projects between the Geological Survey of Denmark and Greenland (GEUS) and the Bureau of Minerals and Petroleum (BMP), Government of Greenland, and wholly funded by the latter. The main purpose of the projects is to attract the interest of the mining industry. The field work comprised systematic drainage sampling, reconnaissance mineral exploration and spectroradiometric measurements of rock surfaces.

Qaanaaq 2001: mineral exploration reconnaissance in North-West Greenland

2002 ◽  
pp. 133-143
Author(s):  
Bjørn Thomassen ◽  
Peter R. Dawes ◽  
Agnete Steenfelt ◽  
Johan Ditlev Krebs
Keyword(s):  
Mineral Exploration ◽  
Mining Industry ◽  
Field Work ◽  
Original Series ◽  
West Greenland ◽  
North West ◽  
Ice Caps ◽  
High Plateau ◽  
Set Up ◽  
Inland Ice

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Thomassen, B., Dawes, P. R., Steenfelt, A., & Krebs, J. D. (2002). Qaanaaq 2001: mineral exploration reconnaissance in North-West Greenland. Geology of Greenland Survey Bulletin, 191, 133-143. https://doi.org/10.34194/ggub.v191.5141 _______________ Project Qaanaaq 2001, involving one season’s field work, was set up to investigate the mineral occurrences and potential of North-West Greenland between Olrik Fjord and Kap Alexander (77°10´N – 78°10´N; Fig. 1). Organised by the Geological Survey of Denmark and Greenland (GEUS) and the Bureau of Minerals and Petroleum (BMP), Government of Greenland, the project is mainly funded by the latter and has the overall goal of attracting the interest of the mining industry to the region. The investigated region – herein referred to as the Qaanaaq region – comprises 4300 km2 of ice-free land centred on Qaanaaq, the administrative capital of Qaanaap (Thule) municipality. Much of the region is characterised by a 500–800 m high plateau capped by local ice caps and intersected by fjords and glaciers. High dissected terrain occurs in Northumberland Ø and in the hinterland of Prudhoe Land where nunataks are common along the margin of the Inland Ice.

The year in focus, 2000

2001 ◽  
pp. 7-10
Author(s):  
Kai Sørensen
Keyword(s):  
Geological Mapping ◽  
Geological Survey ◽  
Seismic Survey ◽  
East Greenland ◽  
Major Field ◽  
Original Series ◽  
West Greenland ◽  
Level Of Activity ◽  
Field Activity ◽  
Year 2000

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Sørensen, K. (2001). The year in focus, 2000. Geology of Greenland Survey Bulletin, 189, 7-10. https://doi.org/10.34194/ggub.v189.5148 _______________ The year 2000 was unusual in that it lacked major field activity directly involved with the systematic geological mapping of Greenland. However, field activities were again many and varied, including a successful highresolution seismic survey offshore central West Greenland, and a joint Geological Survey of Denmark and Greenland (GEUS) – Danish Lithosphere Centre (DLC) project centred on Kangerlussuaq in southern East Greenland. Of the Survey’s 354 personnel, 93 were allocated to Greenland-related activities (Table 1). The Greenland level of activity in 2000, both in Copenhagen and in the field, thus compared favourably with that of 1999.

Conclusion of the 1:500 000 mapping project in the Caledonian fold belt in North-East Greenland

1999 ◽  
pp. 10-22 ◽  
Author(s):  
Niels Henriksen
Keyword(s):  
Field Work ◽  
Fold Belt ◽  
East Greenland ◽  
Original Series ◽  
Preliminary Results ◽  
General Overview ◽  
North East ◽  
Review Articles ◽  
Field Season ◽  
Scientific Results

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Henriksen, N. (1999). Conclusion of the 1:500 000 mapping project in the Caledonian fold belt in North-East Greenland. Geology of Greenland Survey Bulletin, 183, 10-22. https://doi.org/10.34194/ggub.v183.5200 _______________ The second and last field season of the mapping project in the southern part of North-East Greenland (72°–75°N) was carried out in 1998 with full accomplishment of all planned goals. The general overview mapping of the East Greenland Caledonian fold belt has now been completed, in total covering a stretch of more than 1300 km between latitudes 70°N and c. 81°30´N (Fig. 1). The Survey’s systematic regional 1:500 000 mapping programme in the East Greenland Caledonides started with mapping in the Scoresby Sund region (70°–72°N) in 1968, and in the course of 13 field seasons spread over 30 years has involved more than 50 geologists for one or more field seasons each; several Survey geologists have participated in all 13 field seasons. The mapping of the Caledonian fold belt and the adjacent pre- and post-Caledonian rocks will be presented on five 1:500 000 map sheets of which three are already published and a fourth is under compilation. The scientific results are documented in numerous publications both in international journals and in the Survey’s own Bulletins and Reports. Review articles on various parts of the East Greenland Caledonian fold belt include those of Haller (1971), Henriksen & Higgins (1976), Higgins & Phillips (1979), Henriksen (1985, 1986), Hurst et al. (1985), Peel (1985), Peel & Sønderholm (1991), Higgins (1994) and Jepsen et al. (1994). Preliminary results of the 1997 and 1998 field work have been published in Survey reports (Higgins & Frederiksen 1998, 1999), and are summarised by Henriksen (1998) and in this article.

Petroleum geological activities onshore West Greenland in 1997

1998 ◽  
pp. 10-17
Author(s):  
Flemming G. Christiansen ◽  
Anders Boesen ◽  
Jørgen A. Bojesen-Koefoed ◽  
Finn Dalhoff ◽  
Gregers Dam ◽  
...  
Keyword(s):  
Field Work ◽  
Early Summer ◽  
Summer Season ◽  
Project Manager ◽  
Geophysical Survey ◽  
Original Series ◽  
West Greenland ◽  
Low Level ◽  
The Third ◽  
Geophysical Surveys

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Christiansen, F. G., Boesen, A., Bojesen-Koefoed, J. A., Dalhoff, F., Dam, G., Neuhoff, P. S., Pedersen, A. K., Pedersen, G. K., Stannius, L. S., & Zinck-Jørgensen, K. (1998). Petroleum geological activities onshore West Greenland in 1997. Geology of Greenland Survey Bulletin, 180, 10-17. https://doi.org/10.34194/ggub.v180.5079 _______________ The 1997 summer season saw continued petroleum geological activities in the Disko–Nuussuaq–Svartenhuk Halvø area, onshore West Greenland. These activities mainly took the form of a geological field project led by the Geological Survey of Denmark and Greenland (GEUS), whereas the continued exploration by grønArctic Energy Inc. (grønArctic) in the third year of their licence was kept at a very low level without field work, geophysical surveys or drilling. Furthermore an airborne geophysical survey, Aeromag 1997, covering a large part of the Disko Bugt area, was carried out in the early summer of 1997 with GEUS as project manager (Stemp 1997; Stemp & Thorning 1998, this volume).

Reconnaissance for noble metals in Precambrian and Palaeogene rocks, Amdrup Fjord, southern East Greenland

2001 ◽  
pp. 76-80
Author(s):  
Bjørn Thomassen ◽  
Johan Ditlev Krebs
Keyword(s):  
Snow Cover ◽  
Major Part ◽  
Noble Metals ◽  
Field Work ◽  
High Mountain ◽  
East Greenland ◽  
Original Series ◽  
Preliminary Results ◽  
Hydrothermal Veins ◽  
Gold Bearing

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Thomassen, B., & Krebs, J. D. (2001). Reconnaissance for noble metals in Precambrian and Palaeogene rocks, Amdrup Fjord, southern East Greenland. Geology of Greenland Survey Bulletin, 189, 76-80. https://doi.org/10.34194/ggub.v189.5161 _______________ A zone of hydrothermal veins in the Kangerlussuaq region, southern East Greenland, is the focus of a oneyear project by the Geological Survey of Denmark and Greenland (GEUS). The project aims to localise, map, sample and analyse silver-gold-bearing veins in a selected area of Precambrian and Palaeogene rocks north of Amdrup Fjord (Figs 1, 2). This report describes the field work and presents some preliminary results. The study area comprises a c. 3 km wide and 10 km long ridge between Amdrup Fjord and Søndre Syenitgletscher, centred on the 938 m high mountain Flammefjeld (Figs 2, 3). The area is of alpine character with small glaciers and with extensive snow cover most of the year. The field programme was chosen to coincide with the time of minimum snow cover, from 25 July – 23 August. During this period, the major part of the area was investigated on daily foot traverses from four fly camps, helped by helicopter lifts on two occasions. Logistically, the work was part of a larger expedition to East Greenland – EG 2000 – organised by the Danish Lithosphere Centre and GEUS, which is reported on elsewhere (Nielsen et al. 2001, this volume). A temporary field base in Sødalen, some 50 km east of Amdrup Fjord, supported the expedition’s Ecureuil AS 350 helicopter and provided services for the field teams of the various activities attached to EG 2000. Air connections with Iceland were maintained by Twin Otter aircraft operating from a gravel landing strip in Sødalen (Fig. 1).

scholarly journals Eastern North Greenland 1993-1995 - a new 1:500 000 mapping project

1994 ◽  
Vol 160 ◽  
pp. 47-51
Author(s):  
N Henriksen
Keyword(s):  
Field Work ◽  
Geological Survey ◽  
East Greenland ◽  
West Greenland ◽  
North West ◽  
General Overview ◽  
North Greenland

The Geological Survey of Greenland (GGU) initiated in 1964 a 1:500000 mapping programme to produce a general overview of the onshore geology of all the ice-free areas of Greenland. So far 10 of a total of 14 planned map sheets have been published, and one additional sheet for which field work has been completed is under compilation. Most of Greenland is therefore now covered by map sheets of this series and only three areas remain to be covered: in North-West Greenland (sheet 6), in eastern North Greenland (sheet 9) and in East Greenland (sheet 11). Eastern North Greenland (map sheet no. 9; Fig. 1) is the target of the present project, with planned field work from 1993–1995. The first season (1993) was used for logistical preparation and geological reconnaissance in advance of the more intensive field work in the two following seasons (1994–95).

Earth’s oldest well-preserved mafic dyke swarms in the vicinity of the Isua greenstone belt, southern West Greenland

2000 ◽  
pp. 65-72 ◽  
Author(s):  
Rosalind V. White ◽  
James L. Crowley ◽  
John S. Myers
Keyword(s):  
Greenstone Belt ◽  
Current Knowledge ◽  
Field Work ◽  
Mafic Dyke ◽  
Multidisciplinary Research ◽  
Original Series ◽  
West Greenland ◽  
Important Region ◽  
Field Investigations ◽  
Dyke Swarms

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: White, R. V., Crowley, J. L., & Myers, J. S. (2000). Earth’s oldest well-preserved mafic dyke swarms in the vicinity of the Isua greenstone belt, southern West Greenland. Geology of Greenland Survey Bulletin, 186, 65-72. https://doi.org/10.34194/ggub.v186.5217 _______________ The Isukasia region of southern West Greenland contains the Earth’s oldest known supracrustal rocks (the c. 3.8–3.7 Ga Isua greenstone belt: Appel et al. 1998) and well-preserved mafic dyke swarms (Inaluk and Tarssartôq dykes: Nutman et al. 1983). This report describes field investigations of the dykes carried out in 1999 as part of the Isua Multidisciplinary Research Project, and summarises current knowledge of the dykes. The project was initiated in 1997 with the aim of coordinating a detailed reinvestigation of this geologically important region. Fifteen members of the group were involved in field work in 1999 and this article represents only one aspect of the work.

scholarly journals 1990 – a year of change in hydrocarbon-geological activities at the Geological Survey of Greenland

1991 ◽  
Vol 152 ◽  
pp. 11-13
Author(s):  
T.C.R Pulvertaft
Keyword(s):  
Field Work ◽  
Geological Survey ◽  
Final Report ◽  
Reservoir Properties ◽  
East Greenland ◽  
West Greenland ◽  
Concrete Form ◽  
Siliciclastic Sediments

The background for the Geological Survey of Greenland's (GGU's) hydrocarbon-geological activities was briefly outlined in the Report of Activities for 1989 (Stemmerik et al., 1990a). In that report it was intimated that a shift of emphasis in hydrocarbon-geological activities was under way, not only from onshore to offshore but also from East to West Greenland (Fig. 1). 1990 saw this shift take more concrete form. Thus field work in East Greenland was limited to minor projects that focus on diagenesis and reservoir properties of siliciclastic sediments. All other projects onshore East Greenland have reached or are entering into final report stage

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