Aeromagnetic survey in central West Greenland: project Aeromag 2001

Author(s):  
Thorkild M. Rasmussen

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article. Rasmussen, T. M. (1). Aeromagnetic survey in central West Greenland: project Aeromag 2001. Geology of Greenland Survey Bulletin, 191, 67-72. https://doi.org/10.34194/ggub.v191.5130 The series of government-funded geophysical surveys in Greenland was continued during the spring and summer of 2001 with a regional aeromagnetic survey north of Uummannaq, project Aeromag 2001 (Fig. 1). The survey added about 70 000 line kilometres of high-quality magnetic measurements to the existing database of modern airborne geophysical data from Greenland. This database includes both regional high-resolution aeromagnetic surveys and detailed surveys with combined electromagnetic and magnetic airborne measurements.

Author(s):  
Thorkild M. Rasmussen ◽  
Jeroen A.M. Van Gool

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Rasmussen, T. M., & van Gool, J. A. (2000). Aeromagnetic survey in southern West Greenland: project Aeromag 1999. Geology of Greenland Survey Bulletin, 186, 73-77. https://doi.org/10.34194/ggub.v186.5218 _______________ The acquisition of public airborne geophysical data from Greenland that commenced in 1992 continued in 1999 with project Aeromag 1999, an aeromagnetic survey of part of southern West Greenland. This paper presents results of the aeromagnetic survey and discusses the correlation of the measured data with the previously mapped surface geology. The project was financed by the Government of Greenland and managed by the Geological Survey of Denmark and Greenland. Sander Geophysics Ltd., Ottawa, Canada, was selected in April 1999 as the contractor for the project through a European Union opentender procedure.


Author(s):  
Thorkild M. Rasmussen ◽  
Leif Thorning

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Rasmussen, T. M., & Thorning, L. (1999). Airborne geophysical surveys in Greenland in 1998. Geology of Greenland Survey Bulletin, 183, 34-38. https://doi.org/10.34194/ggub.v183.5202 _______________ Airborne geophysical surveying in Greenland during 1998 consisted of a magnetic project referred to as ‘Aeromag 1998’ and a combined electromagnetic and magnetic project referred to as ‘AEM Greenland 1998’. The Government of Greenland financed both with administration managed by the Geological Survey of Denmark and Greenland (GEUS). With the completion of the two projects, approximately 305 000 line km of regional high-resolution magnetic data and approximately 75 000 line km of detailed multiparameter data (electromagnetic, magnetic and partly radiometric) are now available from government financed projects. Figure 1 shows the location of the surveyed areas with highresolution geophysical data together with the area selected for a magnetic survey in 1999. Completion of the two projects was marked by the release of data on 1 March, 1999. The data are included in the geoscientific databases at the Survey for public use; digital data and maps may be purchased from the Survey.


Author(s):  
Robert W. Stemp

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stemp, R. W. (1997). Airborne geophysical surveys in Greenland – 1996 update. Geology of Greenland Survey Bulletin, 176, 75-79. https://doi.org/10.34194/ggub.v176.5069 _______________ Two major airborne geophysical surveys were carried out in 1996, the third year of a planned five-year electromagnetic and magnetic survey programme (project AEM Greenland 1994–1998) financed by the Government of Greenland, and the second year of an aeromagnetic survey programme (project Aeromag) jointly financed by the governments of Denmark and Greenland; both projects are managed by the Geological Survey of Denmark and Greenland (GEUS). The two 1996 surveys were: 1) Project Aeromag 1996 in South-West and southern West Greenland;2) Project AEM Greenland 1996 in South-West Greenland. All areas surveyed and planned for future surveys as of March 1997 are shown in Figure 1. Results of both the 1996 surveys were released in March 1997, as a continuation of a major effort to make high quality airborne geophysical data available for both mineral exploration and geological mapping purposes. The data acquired are included in geoscientific databases at GEUS for public use; digital data and maps may be purchased from the Survey. The main results from the 1996 surveys are described in Thorning & Stemp (1997) and Stemp (1997). Two further new airborne surveys have already been approved for data acquisition during the 1997 field season, with subsequent data release in March 1998. A summary of all surveys completed, in progress or planned since the formal inception of project AEM Greenland 1994–1998 is given in Table 1. The programme was expanded to include a separate regional aeromagnetic survey in 1995, provisionally for 1995–1996, with extension subject to annual confirmation and funding.


Geophysics ◽  
1971 ◽  
Vol 36 (4) ◽  
pp. 695-716 ◽  
Author(s):  
B. K. Bhattacharyya

An automatic method has been developed for compilation of digital aeromagnetic data. This method has been applied to the data obtained during a high‐sensitivity aeromagnetic survey over an area in the Precambrian shield of northeastern Ontario in Canada. With this method, all points of intersection between traverse and base lines are determined automatically and adjusted within the limits of positional error for minimizing differences in magnetic values at the intersections. Then the data are corrected for diurnal variation and leveled to tie the magnetic measurements together. Next, the resulting total field values are contoured with a machine method at a scale of 1:25,000. For such a scale, the minimum contour interval that can be used in the present area is two gammas. However, because of the accuracy of the method of compilation, with a larger scale, it is possible to trace one‐gamma contours. The maps thus compiled have been compared with published aeromagnetic maps of data obtained with conventional flux‐gate and proton‐precession magnetometers. The new maps are vastly superior to the old ones for delineating trends, patterns, and fine features of available detailed geological maps. This superiority is mainly due to the excellent definition of small amplitude anomalies, some of only a few gammas in magnitude, on the high‐resolution magnetic maps.


Author(s):  
Flemming G. Christiansen ◽  
Anders Boesen ◽  
Jørgen A. Bojesen-Koefoed ◽  
Finn Dalhoff ◽  
Gregers Dam ◽  
...  

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).


Author(s):  
Christian Marcussen ◽  
James A. Chalmers ◽  
Holger Lykke Andersen ◽  
Rasmus Rasmussen ◽  
Trine Dahl-Jensen

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Marcussen, C., Chalmers, J. A., Lykke Andersen, H., Rasmussen, R., & Dahl-Jensen, T. (2001). Acquisition of high-resolution multichannel seismic data in the offshore part of the Nuussuaq Basin, central West Greenland. Geology of Greenland Survey Bulletin, 189, 34-40. https://doi.org/10.34194/ggub.v189.5195 _______________ A high-resolution multichannel seismic survey (project NuussuaqSeis 2000) was carried out from 18 July to 2 August 2000 in the offshore part of the Nuussuaq Basin, central West Greenland using the Danish research vessel R/V Dana with seismic equipment from the Geological Institute, Aarhus University, Denmark. Funding for the project was provided by the Danish Energy Research Programme, the Bureau of Minerals and Petroleum, Nuuk, Greenland, the Geological Institute of Aarhus University and the Geological Survey of Denmark and Greenland (GEUS). After completion of the NuussuaqSeis 2000 project, R/V Dana was used for a three-day coring project in Disko Bugt (see Kuijpers et al. 2001, this volume) before the ship returned to Denmark.


1997 ◽  
Vol 28 (1-2) ◽  
pp. 235-241
Author(s):  
R. Leama ◽  
S. Liu ◽  
G. M. Gibson ◽  
D. L. Gibson ◽  
D. W. Maidment ◽  
...  

1969 ◽  
Vol 20 ◽  
pp. 1-25
Author(s):  
M Ghisler ◽  
P.V Sharma

The chromite deposits of the Fiskenæsset region belong to a metamorphosed igneous complex of stratiform type occurring in the basement gneiss unit of older Precambrian age in West Greenland. Short descriptions and modal compositions of the different rock types are given together with the results of magnetic measurements on 60 rock samples (data shown in tables 1-5). On the basis of known geology and rock susceptibilities different models are discussed with respect to the applicability of both an airborne and a ground magnetometer survey. It is concluded that the susceptibility contrasts involved are sufficient for locating favourable host rocks by aeromagnetic survey, but direct magnetic prospecting for chromite horizons predominantly occurring within anorthosites may not be feasible.


1988 ◽  
Vol 140 ◽  
pp. 26-27
Author(s):  
L Thorning

The Geological Survey of Gre.enland plans a major aeromagnetic survey in the Disko Bugt region over the coming years. It has already been started with some introductory work in 1986 and 1987 (Knudsen el al., 1988). In this context, closed-file geophysical data were reviewed at GGU, and it soon became clear that good quality regional aeromagnetic data were lacking from the area and that the geological investigations would benefit from such data. Funds were not available for a systematic survey over the entire area, but in April 1987 a situation arose in which at least part of the area could be surveyed. Due to the change of plans for the aeromagnetic surveying of the GICAS project, described by Thorning el al. (1988), it was possibie to include one survey flight east of Disko Bugt. The measurements were made from the National Aeronauticai Establishment aircraft (CFNRC), which is a well equipped Convair-580 with very good navigational capabilities and a 3-axis magnetic gradiometer.


Author(s):  
Leif Thorning ◽  
Robert W. Stemp

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Thorning, L., & Stemp, R. W. (1998). Airborne geophysical surveys in central West Greenland and central East Greenland in 1997. Geology of Greenland Survey Bulletin, 180, 63-66. https://doi.org/10.34194/ggub.v180.5087 _______________ In order to stimulate mining exploration activity in Greenland the Government of Greenland decided in 1993 to finance a five-year programme of airborne electromagnetic surveys over selected regions of Greenland, Project AEM Greenland 1994–1998. By the end of 1996 three surveys had been undertaken in various parts of Greenland (Stemp & Thorning 1995a, b; Stemp 1996a, b; Stemp 1997a, b). In 1992 the Danish Government financed a small aeromagnetic survey (Project Aeromag 1992; Thorning 1993). Regional aeromagnetic surveying was taken up again when the governments of Denmark and Greenland jointly financed two aeromagnetic surveys in 1995 and 1996 – the projects Aeromag 1995 and Aeromag 1996 (Thorning & Stemp 1997). To this suite of airborne geophysical surveys of selected regions in Greenland were added two surveys in 1997, both financed by the Government of Greenland. The fourth year of Project AEM Greenland 1994–1998 encompassed a transient electromagnetic (GEOTEM) and magnetic survey over northern Jameson Land, central East Greenland, while Project Aeromag 97 added a regional aeromagnetic survey over Disko Bugt – Nuussuaq, central West Greenland. As in previous years, commercial geophysical contractors carried out the survey operations in Greenland according to an agreement with the Geological Survey of Denmark and Greenland (GEUS) entered into after international tendering following rules of the European Union. GEUS manages the projects and organises the distribution and use of the results. The new maps and digital data from the two 1997 surveys, a total of 85 252 line kilometres of data covering 51 414 km2, were released to the public on 1 March 1998. This note provides some introductory information about the two surveys. Further information can be found in reports by Stemp (1998) and Thorning (in press); both include a number of full-page colour anomaly maps from the survey areas. The airborne geophysical programme will continue in 1998, and the areas to be surveyed have already been selected. The final year of Project AEM Greenland 1994–1998 will include combined GEOTEM and magnetic surveys over two regions in North Greenland: Washington Land in western North Greenland, where operations are expected to start in May 1998 operating out of Alert in Canada, and later in the season over J.C. Christensen Land in central North Greenland operating out of Station Nord in eastern North Greenland. Project Aeromag 1998 will continue the regional aeromagnetic survey programme in West Greenland, extending the coverage by including most of the region from 63°45′N to 66°N in southern West Greenland. This project will be based at Nuuk and start in March 1998. The Government of Greenland will finance all surveys in 1998. Figure 1 shows all survey areas for the electromagnetic and magnetic surveys of Project AEM Greenland 1994–1998 and the aeromagnetic survey areas of Project Aeromag 1992, 1995, 1996, 1997 and 1998.


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