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
Författare
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.
Avdelning/ar
- Berggrundsgeologi
Publiceringsår
2020
Språk
Engelska
Publikation/Tidskrift/Serie
Journal of African Earth Sciences
Volym
163
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Geology
Nyckelord
- Gamma-ray spectrometry
- Mafic dyke
- Magnetism
- Mauritania
- Reguibat shield
- Terrane Tasiast-Tijirit
Aktiv
Published
ISBN/ISSN/Övrigt
- ISSN: 1464-343X