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.

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.

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. 

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.

scholarly journals Field work in the north of the Ivisârtoq region, inner Godthåbsfjord, southern West Greenland

1983 ◽  
Vol 115 ◽  
pp. 49-56
Author(s):  
B Chadwick ◽  
M.A Crewe ◽  
J.F.W Park
Keyword(s):  
Field Work ◽  
Geological Survey ◽  
West Greenland ◽  
North West ◽  
The North ◽  
Field Investigations ◽  
New Findings ◽  
Host Rocks

The programme of field investigations in the north of the Ivisartoq region begun in 1981 by Chadwick & Crewe (1982) was continued in 1982. Julia Park began mapping the Taserssuaq granodiorite, its host rocks and the Ataneq fault in the north-west. Dur team was joined by D. Bellur, Geological Survey of India, nominally as an assistant. In this report we present only summary notes of new findings relevant to the interpretation of the geometry and chronology of this segment of the Archaean crust in southern West Greenland. We use the established terminology for the Archaean rocks of the Godthåbsfjord region.

scholarly journals Field investigations in the Precambrian terrain of the Thule district, North-West Greenland

1979 ◽  
Vol 95 ◽  
pp. 14-22
Author(s):  
P.R Dawes
Keyword(s):  
Field Work ◽  
Crystalline Basement ◽  
Field Mapping ◽  
West Greenland ◽  
North West ◽  
Field Investigations ◽  
Precambrian Terrain ◽  
Outer Coast ◽  
Three Phases

The field mapping of the Precambrian crystalline basement and overlying Thule Group of the Thule district aimed at the production of a 1:500000 map sheet between 75°15'N and 78°N was continued in July and August (fig. 5). The field work was split up, due to the varying availability of transport facilities, into three phases. (1) The charter of a Bell 204 helicopter from Thule Air Base enabled mapping in western Inglefield Land, and in the nunatak terrain of Prudhoe Land and Melville Bugt. (2) Investigation of the outer coast of western Melville Bugt was carried out with the aid of GGU cutter K. J. V. Steenstrup. (3) Detailed stratigraphical work in the middle and upper part of the Thule Group was based on foot traverses from Thule Air Base.

scholarly journals 1:500 000 mapping of the Thule district, North-West Greenland

1976 ◽  
Vol 80 ◽  
pp. 23-28
Author(s):  
P.R Dawes
Keyword(s):  
Weather Conditions ◽  
Field Work ◽  
Economic Potential ◽  
West Greenland ◽  
North West ◽  
Field Investigations ◽  
Field Season ◽  
Logistic Support

Field investigations aimed at the produetion of a 1:500 000 map sheet of the Thule distriet were continued during August and early September. The unusuaIly poor weather conditions and the premature arrival of the winter's snowfall, reduced the season to some 20 effective working days. The field work was in two parts. At the beginning of the season a Jet Ranger helicopterwas chartered at Thule Air Base and four days were spent investigating nunatak and inland areas north of Savigsivik and Kap York and at the heads of Wolstenholme Fjord, Olrik Fjord and Inglefield Bredning. The second part was an investigation ofthe Proterozoic Thule Groupon Herbert ø, Northumberland Ø and Hakluyt Ø. Transport for this phase wasa locally hired boat from Avatak Henson of Moriussaq. Certain logistic support was supplied to H. R. Cooke who visited the Thule district at the end of the field season to assess the economic potential of various minerallocalities. Kurt Thomsen ably assisted both in Cooke's and the author's field programmes.

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.

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).

scholarly journals Evolution of the Palaeoproterozoic Nagssugtoqidian orogen: DLC investigations in West Greenland

1995 ◽  
Vol 165 ◽  
pp. 100-105
Author(s):  
M Marker ◽  
F Mengel ◽  
J Van Gool ◽  
Field party
Keyword(s):  
Field Work ◽  
West Greenland ◽  
Field Investigations ◽  
Field Campaigns

During the summer of 1994, the Danish Lithosphere Centre (DLC) initiated geological field investigations of the Nagssugtoqidian orogen in West Greenland as part of a project on the architecture and dynamics of Palaeoproterozoic orogens. The 1994 field work was the first of three field campaigns in the Nagssugtoqidian orogen that have been planned for 1994, 1995 and 1997.

scholarly journals Disko Bugt Project 1991, West Greenland

1992 ◽  
Vol 155 ◽  
pp. 36-41
Author(s):  
F Kalsbeek ◽  
F.G Christiansen
Keyword(s):  
Mineral Resources ◽  
Field Work ◽  
Project Work ◽  
Economic Potential ◽  
West Greenland ◽  
North East ◽  
The North ◽  
Field Investigations ◽  
Second Year ◽  
Proterozoic Basement

One of GGU's major field activities in 1991 took place in July and August in the Disko Bugt region of central West Greenland. This was the third year of field investigations under the 'Disko Bugt Project', planned for 1999–1992, with one summer's break in 1990. The project spreads over various activities and over two very different geological provinces: the Archaean-Proterozoic basement east and north-east of Disko Bugt, and the onshore part of the Cretaceous-Tertiary basin in the west, on Disko and the western part of Nugssuaq (Fig. 1). In 1989, the second year of the project, work was concentrated in the eastern basement part of the study area, and in 1991 this work was brought to conclusion. In 1992 field work (including a shallow core drilling campaign) will be concentrated in the sediments and volcanics on Nugssuaq and Svartenhuk Halvø to the north. The main aim of the Disko Bugt Project is to provide a background for the evaluation of the economic potential of the regional mineral resources, mainly in the Precambrian basement, and the hydrocarbon potential of the neighbouring basin offshore (see Kalsbeek, 1989. 1990).

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