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

Moussa Hamath Ba; Mohammed Jaffal; Khalidou Lo; Nasrrddine Youbi; Mohamed El Mokhtar Dahmada; Hassan Ibouh; Moulay Ahmed Boumehdi; Tahar Aifa; Massinissa Amara; Mark Jessell; Richard Ernst; Mohamed Khalil Bensalah; Ulf Söderlund

doi:10.1016/j.jafrearsci.2019.103749

Journal articles

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

Moussa Hamath Ba ¹ Mohammed Jaffal ² Khalidou Lo ³ Nasrrddine Youbi ⁴ Mohamed El Mokhtar Dahmada Hassan Ibouh ⁵ Moulay Ahmed Boumehdi ⁵ Tahar Aifa ⁶ Massinissa Amara ⁷ Mark Jessell ^{8, 9} Richard Ernst ^{10, 11} Mohamed Khalil Bensalah ^{12, 5} Ulf Söderlund ^{13, 14}

1 UNA - Université de Nouakchott Al-Aasriya

2 Faculté des Sciences et Techniques

3 Université de Nouakchott

4 UCA - Université Cadi Ayyad [Marrakech]

5 UCA - University of Cadi Ayyad

6 GR - Géosciences Rennes

7 USTHB - University of Sciences and Technology Houari Boumediene [Alger]

8 UWA - The University of Western Australia

9 GET - Géosciences Environnement Toulouse

10 Carleton University

11 Tomsk State University [Tomsk]

12 ULISBOA - Universidade de Lisboa

13 Lund University [Lund]

14 NRM - Swedish Museum of Natural History

Abstract : Analysis of an airborne geophysical data covering the Tasiast-Tijirit Terrane in the western part of the ReguibatShield (including the 1:200,000 geological sheets of Chami, Ahmeyim and Atar), provided an improved mappingof mafic dyke swarms, structural features, and hydrothermal alteration zones. It also extended the mapping intoextensive areas covered by sand. A low-altitude (100 m) airborne survey collected high-resolution magnetic andgamma-ray spectrometry data. The magnetic data were enhanced using techniques such as reduction to the pole,analytic signal andfirst vertical derivative, and revealed dyke swarms with trends of NNE-SSW to NE-SW, NW-SEto WNW-ESE and E-W. The use of the Euler deconvolution method provided constraints on the continuity andthe depth of magnetic sources.Gamma-ray spectrometry which maps the three main radioactive elements, i.e. potassium, uranium andthorium helped discriminate lithological units of the Archean basement, notably felsic intrusions. The radio-metric data also helped delineate potassic alteration zones, which could testify to hydrothermal activities ofrelevance to sulfide mineralisation.

Document type :

Journal articles

Domain :

Sciences of the Universe [physics] / Earth Sciences / Geophysics [physics.geo-ph]

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https://hal-insu.archives-ouvertes.fr/insu-02428998
Contributor : Isabelle Dubigeon <>
Submitted on : Monday, January 6, 2020 - 1:17:24 PM
Last modification on : Thursday, January 14, 2021 - 11:40:20 AM

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

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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

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