Abstract
In Ordovician and Silurian sedimentary formations of the Murzuq basin (Saharan platform, Algeria), different remagnetization processes have been highlighted. These magnetic overprints totally replaced the primary magnetization. They are mainly due to chemical phenomena. Even in a site affected by contact metamorphism during Devonian, chemical changes, associated to the acquisition of the thermo-remanent overprint, were important, affecting the characteristics of the magnetite grains. In the remaining sites, remagnetizations of Cenozoic age have also a chemical origin and are carried by magnetite as well as by hematite. Contrary to what is generally deemed, these remagnetizations processes appeared limited to very short duration of acquisition, and to very local geographical extension.
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Acknowledgements
This project was supported by the Algerian-French PICS cooperation program “Architecture lithosphérique et dynamique du manteau sous le Hoggar”. We are very grateful to the civil and military authorities at Djanet for help during the fieldwork. Thanks also to the two anonymous reviewers for comments.
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This article is part of the Topical Collection on Current Advances in Geology of North Africa
H. Bouabdallah now at geoexplo: www.geoexplo.dz
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Amenna, M., Derder, M.E.M., Henry, B. et al. Chemical remagnetization acquisition processes: case study of the Saharan basins (Algeria). Arab J Geosci 10, 379 (2017). https://doi.org/10.1007/s12517-017-3165-z
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DOI: https://doi.org/10.1007/s12517-017-3165-z