scholarly journals Geophysical investigations at the Inland Ice margin of the Pâkitsoq basin, central West Greenland

1986 ◽  
Vol 130 ◽  
pp. 114-121
Author(s):  
L Thorning ◽  
H.H Thomsen ◽  
E Hansen
Keyword(s):  
Field Work ◽  
Magnetic Survey ◽  
West Greenland ◽  
Considerable Success ◽  
Marginal Areas ◽  
Geophysical Investigations ◽  
Ground Magnetic ◽  
Inland Ice

In recent years much effort has been directed towards investigation of the margin of the Inland Ice in connection with possible development of hydropower. The thickness of the ice and thus the subglacial relief has been difficult to determine. Electromagnetic reflection (EMR) techniques have been used over large parts of the Inland Ice with considerable success, but have so far not produced good results in the marginal areas of the Inland Ice. This note reports the successful application of EMR techniques to an area of the Inland Ice adjacent to the Piikitsoq basin near Jakobshavn, central West Greenland, together with a ground magnetic survey over a smaller part of the area. The field areas are shown in fig 1. The field work was carried out by LT and ER during a five week period in July-August 1985.

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.

Magnetic survey – ground technology, aeromagnetic survey on aircraft and unmanned aerial vehicles: a comparative analysis of the results (on the example of Eastern Transbaikalia)

2020 ◽  
Vol 26 (8) ◽  
pp. 6-15
Author(s):  
R. Gruzdev ◽  
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Geophysical Methods ◽  
Work Productivity ◽  
Field Work ◽  
Magnetic Survey ◽  
Aeromagnetic Survey ◽  
Aerial Vehicles ◽  
Eastern Transbaikalia ◽  
Actual Material ◽  
Ground Magnetic

The use of unmanned aerial vehicles (UAVs) in geophysical work is becoming a very popular area in the field of modern geological exploration. The advantage of unmanned systems is the optimal ratio of the quality of research results with a significant increase in work productivity and a decrease in cost. In this regard, the improvement of field techniques and the processing of UAV materials is of particular interest for exploration. On the subject, there are a number of unresolved issues that have been revealed to some extent as a result of the author’s comparison of ground-based magnetic exploration and aeromagnetic survey data. The purpose of the study was to assess the possibility of a full-fledged replacement of ground magnetic exploration work for aeromagnetic survey using unmanned aerial vehicles. The comparison of different types of magnetic survey is relevant, since on the basis of the actual material, the possibility of using an alternative more productive method – aeromagnetic survey using modern UAVs – instead of traditional expensive ground-based magnetic exploration works is analyzed. To compare the results of the studies, actual material obtained from field work on an area of 13,4 km2 was used. Based on the databases, maps of anomalous magnetic field and graphs on several geophysical profiles are built. Results of magnetic survey in air and ground versions are analyzed; correlation relationships between data of ground pedestrian magnetic survey and aeromagnetic system on An-3 and UAV aircraft are established. Based on the results of the study, correlation and determination coefficients were obtained, which indicate that geophysical methods on UAVs adequately occupy their place between classical aerogeophysics and ground-based pedestrian survey. Moreover, aeromagnetic survey using UAVs is able to replace pedestrian magnetic exploration during work at the same heights. Based on the results of the study, methodological recommendations for the production of aeromagnetic survey on UAVs were compiled

scholarly journals Energy balance on outlet glaciers from the Inland Ice, West Greenland

1987 ◽  
Vol 135 ◽  
pp. 99-105
Author(s):  
N.T Knudsen ◽  
O Ottosen ◽  
L.M Svendsen
Keyword(s):  
Energy Balance ◽  
Direct Calculation ◽  
Field Measurements ◽  
Field Work ◽  
Glacier Surface ◽  
West Greenland ◽  
Residual Part ◽  
Energy Balances ◽  
Inland Ice ◽  
Student Thesis

As part of the GGU programme of hydropower investigations in West Greenland, energy balance measurements were made on Qamanârssûp serrnia during the 1986 ablation season. The investigations are the continuation of a project in which Aarhus University has measured energy balances on Nordbogletscher, Johan Dahl Land, in 1981 and 1982 and on Qamanârssûp serrnia in 1984 in coIlaboration with P. Clement and R. J. Braithwaite, respectively (fig. 1). The main point of the programme was direct calculation of the ablation at the glacier surface from observations in the atmospheric boundary layer. Measured ablation was also used to calculate the residual part of the energy balance, as all elements were not determined. Lastly, the ablation was evaluated using variables chosen by correlation between easily measured climatic elements and the energy balance. The measurements in Johan Dahl Land were made by Jens Peter Jensen and Ole Ottosen as part of a student thesis project. Ole Bendixen undertook field measurements in 1984 on Qamanârssûp serrnia while Ole Ottosen and Lars Moeslund Svendsen carried out the field work in 1986.

scholarly journals Noritic rocks and associated nickel-copper-sulphide occurrences in Sukkertoppen district, central West Greenland

1983 ◽  
Vol 115 ◽  
pp. 30-34
Author(s):  
K Secher
Keyword(s):  
Mineral Resources ◽  
Field Work ◽  
General Description ◽  
Copper Sulphide ◽  
West Greenland ◽  
Gneiss Complex ◽  
Nickel Copper ◽  
Geophysical Investigations ◽  
Geochemical Investigation ◽  
Rock Suite

Field work in 1982 included detailed mapping and collection of samples of sulphide occurrences in the so called 'norite belt', Sukkertoppen district. Several nickel-copper-sulphide mineralisations related to norite rocks are known from the work of Kryolitselskabet Øresund A/S who mapped this rock suite and carried out exploratory investigations of the sulphides (Nielsen, 1976). The earlier mapping has revealed a suite of metabasic plutonic rocks of mainly noritic composition which are situated in an arcuate belt, approximately 15 x 75 km, curving around the Finnefjeld gneiss complex east of Sukkertoppen (fig. 8). Metanorites are embedded in quartzo-feldspathic gneisses and rarely in amphibolitic rocks, and they occur as a series of irregular pods up to 6 km Iong within the arcuate belt. The present investigation was carried out as part of GGU's mineral resources mapping and evaluation programme in central West Greenland, which this year focussed on the area covered by the 1:250000 map sheet 65 V.2. The fieId work was carried out in dose cooperation with teams doing systematic reconnaissance geochemical stream-sediment and water sampling (to be discussed elsewhere), detailed soil geochemical investigation (Jensen & Secher, this report) and experimental geophysical investigations (Thorning, this report). The present work aimed at a general description of the structure and the metallogenetic behaviour of the known norite-related sulphide occurrences in order to reach an understanding of the mineral genesis within this section of the Archaean environment.

scholarly journals Detailed ground magnetic survey in the central part of the Sarfartôq carbonatite complex, southern West Greenland

1982 ◽  
Vol 110 ◽  
pp. 32-38
Author(s):  
K Secher ◽  
L Thorning
Keyword(s):  
Magnetic Survey ◽  
Carbonatite Complex ◽  
West Greenland ◽  
Ground Magnetic

A detailed ground magnetic survey was carried out by the authors and Egon Hansen, electronics technician, during the spring of 1981 in the central part of the Sarfart6q carbonatite complex near Søndre Strømfjord. It was important for the survey that there was continuity of measurements over the whole area, and as most of the area was covered by swamp in the bottom of the valley Arnangarnqup kua, it was most convenient to make the survey when the surface was frozen.

scholarly journals Reconnaissance mapping for the 1:500 000 map sheet in the Godthåb–Isua region, southern West Greenland

1977 ◽  
Vol 85 ◽  
pp. 50-54
Author(s):  
J.H Allaart ◽  
S.B Jensen ◽  
V.R McGregor ◽  
B.J Walton
Keyword(s):  
Field Work ◽  
Coastal Areas ◽  
West Greenland ◽  
The North ◽  
Base Camp ◽  
Inland Ice ◽  
Inner Parts

A two summer reconnaissance mapping programme covering the region east of Godthåb and Sukkertoppen was started in 1976 in order to complete the field work for the 1:500000 map sheet Frederikshåb Isblink - Søndre Strømfjord (62° 30'-66° 45'N). Most of the coastal areas have been visited previously and the earliest results were published as a reconnaissance map (Noe-Nygaard & Ramberg, 1961). The area immediately north of Itivnera was mapped by Walton in 1975 (Walton, 1976), and the area around Isukasia was mapped by Allaart in 1974 and 1975 (Allaart, 1975, 1976). During the 1976 summer the folIowing areas were covered: south of the fjord Ameragdla, around the inner parts of Godthåbsfjord and to the north along the edge ofthe Inland Ice to Isua, and between Godthåbsfjord and Fiskefjord (fig. 14). At the same time C. R. L. Friend & R. P. Hall (see this report) carried out more detailed mapping of the Ivisârtoq area. The mapping team of four geologists was supported by two Bell G 3 helicopters that operated from a base camp established at the reindeer station Itivnera. Transport of equipment, fuel and personnel was by GGU motor cutter F. Johnstrup.

scholarly journals Ground magnetic investigations of selected aeromagnetic anomalies in southern West Greenland

1979 ◽  
Vol 95 ◽  
pp. 63-66
Author(s):  
B.S Mielby ◽  
F Svendsen
Keyword(s):  
Field Work ◽  
Total Field ◽  
Aeromagnetic Anomalies ◽  
West Greenland ◽  
Ground Magnetic

Ground magnetic investigations were carried out during the summer of 1978 to elucidate some prominent aeromagnetic anomalies (Thorning, 1976, 1977). Four different areas were visited (Thorning, this report, fig. 23), additional reconnaissance work being carried out for Leif Thorning on the Taserssuaq granodiorite north of Godthåbsfjord (Thorning, this report). During the field work, total field magnetic profiles were obtained using a proton magnetometer (Geometrics G-816) and in situ susceptibilities were measured with an ABEM Kappameter KT-3.

scholarly journals Mapping of the Isukasia sheet, southern West Greenland

1983 ◽  
Vol 115 ◽  
pp. 20-29
Author(s):  
A.A Garde ◽  
R.P Hall ◽  
D.J Hughes ◽  
S.B Jensen ◽  
A.P Nutman ◽  
...  
Keyword(s):  
Field Work ◽  
Late Archaean ◽  
West Greenland ◽  
North East ◽  
The North ◽  
Base Camp ◽  
Geophysical Investigations ◽  
Set Up

Field work for the Isukasia map sheet north of Godthåbsfjord, started in 1981 (Allaart et al., 1982), was continued in 1982. A tent base camp was set up at the fjord Kangiussaq both summers. In 1982 seventeen fjeld teams and the glaciological station Qamanârssup sermia were supplied from the base by the GGU cutter J. F. Johnstrup and by a Jet Ranger helicopter based in Kangiussaq. Twelve mapping geologists worked on the two map sheets Ivisartoq and Isukasia, and five teams carried out ore geological, geochemical and geophysical investigations (see Appel, Chadwick et al., Jensen & Secher, and Secher, this volume). The field work was carried out from June 20th to August 28th. The Isukasia map sheet is situated north-east of the head of Fiskefjord, around the lake Taserssuaq. To the east it is bounded by the Inland lee, from which the glacier Sarqap sermia enters Taserssuaq. Most of the area is a lake strewn, undulating plateau at elevations between 500 and 800 m. Outcrops are generally good aIthough there are some Quaternary boulder fields, the largest of whieh extends over some 25 km2 in the north-east corner of the map sheet. The north-north-east trending Ataneq fauIt zone (see below), which oeeurs some 25 km east of Taserssuaq, separates an area of early Archaean rocks (induding the Isua supracrustals) from rocks to its west of probable late Archaean age. The younger rocks make up the bulk of the Isukasia map sheet.

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. 

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