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Paleomagnetism and U-Pb age of the 2.4 Ga Erayinia mafic dykes in the south-western Yilgarn, Western Australia: Paleogeographic and geodynamic implications

Pisarevsky, Sergei A.; De Waele, Bert; Jones, Sarah; Söderlund, Ulf LU and Ernst, Richard E. (2015) In Precambrian Research 259. p.222-231
Abstract
We present results from a paleomagnetic study of the previously undated Erayinia dykes intruding the south-western Yilgarn Craton. The U-Pb TIMs baddeleyite age of these dykes is now 2401 +/- 1 Ma, which is about 10 m.y. younger than the 2418-2410 Ma Widgiemooltha dyke swarm. The paleomagnetic study isolated a stable primary remanence with steep downward direction, and the paleomagnetic pole (22.7 degrees S. 150.5 degrees E, A(95) = 11.4 degrees) is similar, but not identical to that of the previously studied Widgiemooltha dykes. We interpret this difference as the result of the movement of the Yilgam Craton toward the pole at similar to 1 degrees/m.y. angular speed, which is comparable with tectonic plates' velocities during the... (More)
We present results from a paleomagnetic study of the previously undated Erayinia dykes intruding the south-western Yilgarn Craton. The U-Pb TIMs baddeleyite age of these dykes is now 2401 +/- 1 Ma, which is about 10 m.y. younger than the 2418-2410 Ma Widgiemooltha dyke swarm. The paleomagnetic study isolated a stable primary remanence with steep downward direction, and the paleomagnetic pole (22.7 degrees S. 150.5 degrees E, A(95) = 11.4 degrees) is similar, but not identical to that of the previously studied Widgiemooltha dykes. We interpret this difference as the result of the movement of the Yilgam Craton toward the pole at similar to 1 degrees/m.y. angular speed, which is comparable with tectonic plates' velocities during the Phanerozoic. Paleomagnetic polarities of Widgiemooltha and Erayinia dykes suggest that at least one geomagnetic reversal occurred between these two magmatic events. The estimated amplitude of geomagnetic secular variations at c. 2400 Ma is slightly higher than predicted by the existing models for the last 5 m.y. at the c. 64 degrees latitude. The paleomagnetic data and patterns of c. 2.6-2.1 Ga mafic dyke swarms permit the recently suggested reconstruction of the Paleoproterozoic supercontinent. (C) 2014 Elsevier B.V. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Paleomagnetism, U-Pb TIMs age, Paleoproterozoic, Yilgarn Craton, Mafic, dykes, Supercontinent
in
Precambrian Research
volume
259
pages
222 - 231
publisher
Elsevier
external identifiers
  • wos:000350516900015
  • scopus:85027925849
ISSN
0301-9268
DOI
10.1016/j.precamres.2014.05.023
language
English
LU publication?
yes
id
62dea8b3-9b88-4dc1-87b9-b3c79baad69c (old id 5300423)
date added to LUP
2015-04-27 10:03:37
date last changed
2017-10-01 03:02:42
@article{62dea8b3-9b88-4dc1-87b9-b3c79baad69c,
  abstract     = {We present results from a paleomagnetic study of the previously undated Erayinia dykes intruding the south-western Yilgarn Craton. The U-Pb TIMs baddeleyite age of these dykes is now 2401 +/- 1 Ma, which is about 10 m.y. younger than the 2418-2410 Ma Widgiemooltha dyke swarm. The paleomagnetic study isolated a stable primary remanence with steep downward direction, and the paleomagnetic pole (22.7 degrees S. 150.5 degrees E, A(95) = 11.4 degrees) is similar, but not identical to that of the previously studied Widgiemooltha dykes. We interpret this difference as the result of the movement of the Yilgam Craton toward the pole at similar to 1 degrees/m.y. angular speed, which is comparable with tectonic plates' velocities during the Phanerozoic. Paleomagnetic polarities of Widgiemooltha and Erayinia dykes suggest that at least one geomagnetic reversal occurred between these two magmatic events. The estimated amplitude of geomagnetic secular variations at c. 2400 Ma is slightly higher than predicted by the existing models for the last 5 m.y. at the c. 64 degrees latitude. The paleomagnetic data and patterns of c. 2.6-2.1 Ga mafic dyke swarms permit the recently suggested reconstruction of the Paleoproterozoic supercontinent. (C) 2014 Elsevier B.V. All rights reserved.},
  author       = {Pisarevsky, Sergei A. and De Waele, Bert and Jones, Sarah and Söderlund, Ulf and Ernst, Richard E.},
  issn         = {0301-9268},
  keyword      = {Paleomagnetism,U-Pb TIMs age,Paleoproterozoic,Yilgarn Craton,Mafic,dykes,Supercontinent},
  language     = {eng},
  pages        = {222--231},
  publisher    = {Elsevier},
  series       = {Precambrian Research},
  title        = {Paleomagnetism and U-Pb age of the 2.4 Ga Erayinia mafic dykes in the south-western Yilgarn, Western Australia: Paleogeographic and geodynamic implications},
  url          = {http://dx.doi.org/10.1016/j.precamres.2014.05.023},
  volume       = {259},
  year         = {2015},
}