Geophysical characteristics of the northern Cordillera

2021 ◽  
Author(s):  
N Hayward ◽  
J J Ryan
Keyword(s):  
Data Interpretation ◽  
Mineral Deposit ◽  
Geological Mapping ◽  
Geophysical Data ◽  
Geological Survey ◽  
Aeromagnetic Data ◽  
Data Set ◽  
Tectonic Development ◽  
Legacy Data ◽  
Definition Of

Geophysical data acquired under the Geological Survey of Canada's GEM Cordillera project provide a foundation to a broad range of geological investigations in the northern Canadian Cordillera. For areas of specific geological interest, over 230 000 km of high-resolution aeromagnetic data form a mosaic of comprehensive coverage over a total area of more than 82 000 km2. The data provide a powerful and valuable legacy data set for current and future activities by the Geological Survey of Canada and academic and industry partners and clients. Foremost, geophysical data interpretation complements surface geological mapping, especially in inaccessible terrain where bedrock exposure is commonly poor, enabling clearer definition of a region's geology and structure. Beyond applications to bedrock geological mapping, geophysical modelling, integrated with geological results, affords an improved understanding of the deeper crustal structure, leading to new models of the region's tectonic development and mineral deposit context.

scholarly journals Structural Exploration of Aeromagnetic Data over Part of Gwagwalada, Abuja for Potential Mineral Targets Using Derivatives Filters

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Egbelehulu Priscillia ◽  
Abu Mallam ◽  
Abel U. Osagie ◽  
Adewumi Taiwo
Keyword(s):  
Mineral Deposit ◽  
Geological Mapping ◽  
Geological Survey ◽  
Economic Interest ◽  
Aeromagnetic Data ◽  
Horizontal Gradients ◽  
Fault Lines ◽  
Tilt Derivative

Aeromagnetic data are consistently used for economic interest targeting and geological mapping. Besides solving problems that are concerned with the basement, the method has become a useful tool in exploring minerals,hydrocarbons occurrence,groundwater investigations, and geothermal potentials. This study analyses aeromagnetic data from the Nigerian Geological Survey Agency acquired at 100 m terrain clearance over a section of Gwagwalada in Abuja. The study area spans longitudes 7.0875° E to 7.1458° E and latitude 8.9625° N to 9.0° N (about 27 km2 ). After a reduction to the equator (RTE) transformation, the data is downward continued by 50 m. Different filters are applied to outline area of alteration associated to mineral deposit. Regional geologic structures trend NE - SW.The application of vertical derivatives (FVD and SVD) to the RTE grid enhanced shallow structures which trend NE - SW. Horizontal gradients along the X- and Y- directions enhance geological contacts attributable to blind faults. The Tilt derivative (TD) accentuated fault lines which trend NE - SW.

scholarly journals Reconnaissance aeromagnetic survey east of Disko Bugt, central West Greenland

1988 ◽  
Vol 140 ◽  
pp. 26-27
Author(s):  
L Thorning
Keyword(s):  
Geophysical Data ◽  
Geological Survey ◽  
Aeromagnetic Data ◽  
Aeromagnetic Survey ◽  
Entire Area ◽  
West Greenland ◽  
Systematic Survey

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.

scholarly journals Aeromagnetic survey in south-eastern Greenland: project Aeromag 2013

1969 ◽  
Vol 31 ◽  
pp. 63-66
Author(s):  
Peter Riisager ◽  
Thorkild M. Rasmussen
Keyword(s):  
Strategic Planning ◽  
Data Acquisition ◽  
Geological Mapping ◽  
Geophysical Data ◽  
Aeromagnetic Data ◽  
Aeromagnetic Survey ◽  
Almost Everywhere ◽  
Short Period ◽  
Wide Range ◽  
Reasonable Cost

Aeromagnetic surveys are nowadays used at a wide range of scales and purposes. In frontier and under-explored areas, where data are otherwise sparse or non-existent, aeromagnetic acquisition remains the cheapest and easiest way to obtain or refine a picture of the structural setting. Aeromagnetic data are also useful for strategic planning of geological mapping campaigns and detailed geophysical data acquisition. Moreover, aeromagnetic data are of importance for prospecting, helping to define prospects. Large aeromagnetic surveys can be carried out efficiently and safely almost everywhere, in a short period of time and at reasonable cost.

Aeromagnetic survey in southern West Greenland: project Aeromag 1999

2000 ◽  
pp. 73-77 ◽  
Author(s):  
Thorkild M. Rasmussen ◽  
Jeroen A.M. Van Gool
Keyword(s):  
European Union ◽  
Measured Data ◽  
Geophysical Data ◽  
Geological Survey ◽  
Aeromagnetic Survey ◽  
Original Series ◽  
West Greenland ◽  
The Government ◽  
Airborne Geophysical Data ◽  
Surface Geology

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.

Airborne geophysical surveys in Greenland in 1998

1999 ◽  
pp. 34-38 ◽  
Author(s):  
Thorkild M. Rasmussen ◽  
Leif Thorning
Keyword(s):  
High Resolution ◽  
Geophysical Data ◽  
Digital Data ◽  
Geological Survey ◽  
Magnetic Data ◽  
Magnetic Survey ◽  
Original Series ◽  
Geophysical Surveys ◽  
The Government

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.

Exploration history and place names of northern East Greenland

1969 ◽  
Vol 21 ◽  
pp. 1-368 ◽  
Author(s):  
Anthony K. Higgins
Keyword(s):  
20Th Century ◽  
19Th Century ◽  
Geological Mapping ◽  
Geological Survey ◽  
The Arctic ◽  
Place Names ◽  
East Greenland ◽  
New Name ◽  
Systematic Compilation

The first recorded landing by Europeans on the coast of northern East Greenland (north of 69°N) was that of William Scoresby Jr., a British whaler, in 1822. This volume includes a chronological summary of the pioneer 19th century exploration voyages made by British, Danish, Norwegian, Swedish, French and German expeditions – all of whom reported that the region had previously been occupied by the Inuit or Eskimo; also included are brief outlines of the increasing number of government and privately sponsored expeditions throughout the 20th century, whose objectives included cartography, geology, zoology, botany, trapping and the ascent of the highest mountain summits. In 1934 the Place Name Committee for Greenland was established, the tasks of which included a review of all place names hitherto recorded on published maps of Greenland, their formal adoption in danicised form, and the approval or rejection of new name proposals. In northern East Greenland, by far the largest numbers of new place names were those proposed by scientists associated with Lauge Koch's geological expeditions that lasted from 1926 until 1958. This volume records the location and origin of more than 3000 officially approved place names as well as about 2650 unapproved names. The author's interest in the exploration history and place names of northern East Greenland started in 1968, when the Geological Survey of Greenland initiated a major five-year geological mapping programme in the Scoresby Sund region. Systematic compilation of names began about 1970, initially with the names given by William Scoresby Jr., and subsequently broadened in scope to include the names proposed by all expeditions to northern East Greenland. The author has participated in 16 summer mapping expeditions with the Survey to northern East Greenland. Publication of this volume represents the culmination of a lifetime working in the Arctic.

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.

scholarly journals Has the Credibility of the Social Sciences Been Credibly Destroyed? Reanalyzing the “Many Analysts, One Data Set” Project

2021 ◽  
Vol 7 ◽  
pp. 237802312110244
Author(s):  
Katrin Auspurg ◽  
Josef Brüderl
Keyword(s):  
Social Sciences ◽  
Causal Reasoning ◽  
Research Question ◽  
Social Science Research ◽  
Science Research ◽  
Skin Tone ◽  
Data Set ◽  
The Social ◽  
The Many ◽  
Definition Of

In 2018, Silberzahn, Uhlmann, Nosek, and colleagues published an article in which 29 teams analyzed the same research question with the same data: Are soccer referees more likely to give red cards to players with dark skin tone than light skin tone? The results obtained by the teams differed extensively. Many concluded from this widely noted exercise that the social sciences are not rigorous enough to provide definitive answers. In this article, we investigate why results diverged so much. We argue that the main reason was an unclear research question: Teams differed in their interpretation of the research question and therefore used diverse research designs and model specifications. We show by reanalyzing the data that with a clear research question, a precise definition of the parameter of interest, and theory-guided causal reasoning, results vary only within a narrow range. The broad conclusion of our reanalysis is that social science research needs to be more precise in its “estimands” to become credible.

Comprehensive Analysis of the Geological and Geophysical Data in the Study of the Upper Miocene Turbidite Systems of the Nam Con Son Basin, Vietnam

2021 ◽  
Author(s):  
Mariia Kurianova ◽  
Ekaterina Birkle ◽  
Tatiana Egorkina ◽  
Sergey Koltsov
Keyword(s):  
Data Interpretation ◽  
Comprehensive Analysis ◽  
Geophysical Data ◽  
Saint Petersburg ◽  
Upper Miocene ◽  
Branch Office ◽  
Sand Bodies

Abstract The article considers the approaches to the G&G data interpretation used in the Branch Office of Gazprom International in Saint Petersburg (hereinafter referred to as "GPEPI") when studying the geology aspects of turbidite deposits. This approach is showcased on one of the Upper Miocene deposits of the Nam Con Son Basin in Vietnam, and a conclusion is drawn about the possibility of using this complex technique in the study of sand bodies of any genesis.

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