
Ulf Söderlund
Professor

Mapping mafic dyke swarms, structural features, and hydrothermal alteration zones in Atar, Ahmeyim and Chami areas (Reguibat Shield, Northern Mauritania) using high-resolution aeromagnetic and gamma-ray spectrometry data
Author
Summary, in English
Analysis of an airborne geophysical data covering the Tasiast-Tijirit Terrane in the western part of the Reguibat Shield (including the 1:200,000 geological sheets of Chami, Ahmeyim and Atar), provided an improved mapping of mafic dyke swarms, structural features, and hydrothermal alteration zones. It also extended the mapping into extensive areas covered by sand. A low-altitude (100 m) airborne survey collected high-resolution magnetic and gamma-ray spectrometry data. The magnetic data were enhanced using techniques such as reduction to the pole, analytic signal and first vertical derivative, and revealed dyke swarms with trends of NNE-SSW to NE-SW, NW-SE to WNW-ESE and E-W. The use of the Euler deconvolution method provided constraints on the continuity and the depth of magnetic sources. Gamma-ray spectrometry which maps the three main radioactive elements, i.e. potassium, uranium and thorium helped discriminate lithological units of the Archean basement, notably felsic intrusions. The radiometric data also helped delineate potassic alteration zones, which could testify to hydrothermal activities of relevance to sulfide mineralisation.
Department/s
- Lithosphere and Biosphere Science
Publishing year
2020
Language
English
Publication/Series
Journal of African Earth Sciences
Volume
163
Links
Document type
Journal article
Publisher
Elsevier
Topic
- Geology
Keywords
- Gamma-ray spectrometry
- Mafic dyke
- Magnetism
- Mauritania
- Reguibat shield
- Terrane Tasiast-Tijirit
Status
Published
ISBN/ISSN/Other
- ISSN: 1464-343X