Palaeomagnetic investigation of Palaeoproterozoic dykes from Botswana
File(s)
Published version
Author(s)
Tshwenyego, Kemiso
King, James
Muxworthy, Adrian
Qi, LIang
Type
Journal Article
Abstract
The geomagnetic field including its intensity is poorly constrained during the Proterozoic era (2500 to 541 Ma). Understanding geomagnetic field behaviour during this long-time interval is key to understand the evolution of the Earth including dating the age of the Earth’s inner core nucleation. Palaeointensity experiments suggest low magnetic field intensities during the Palaeoproterozoic era between (2500 to 1500 Ma). To address this issue, we present palaeodirectional and palaeointensity results conducted on three previously dated Palaeoproterozoic localities in Botswana: 1) the Moshaneng Complex gabbros (2054 ± 2 Ma), 2) the Moshaneng dolerite dykes (1927 ± 1.5 Ma), and 3) the Pilanesberg dolerite dykes (1347 ± 97 Ma). Virtual geomagnetic poles were obtained from all three localities. Only the Moshaneng dolerite dyke yielded a virtual dipole moment (VDM) of 2.4 ± 0.4 × 1022Am2 from the three studied sites, which is consistent with a dipole low during the Palaeoproterozoic era. The results show that during the Palaeoproterozoic era, there was low VDM recorded which is similar to other values obtained in similarly aged Palaeoproterozoic studies.
Date Issued
2026-04-01
Date Acceptance
2025-12-02
Citation
Journal of African Earth Sciences, 2026, 236
ISSN
1464-343X
Publisher
Elsevier
Journal / Book Title
Journal of African Earth Sciences
Volume
236
Copyright Statement
Copyright © 2025 Published by Elsevier Ltd. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Identifier
10.1016/j.jafrearsci.2025.105954
Publication Status
Published
Article Number
105954
Date Publish Online
2025-12-04