Paleomagnetic and geochronological studies on Paleoproterozoic diabase dykes of Karelia, East Finland-Key for testing the Superia supercraton
(2014) In Precambrian Research 244. p.87-99- Abstract
- Paleomagnetic results are presented for two Paleoproterozoic mafic dykes in the Taivalkoski area in northern Karelia Province of the Fennoscandian shield where, based on K-Ar data, the crust has seen minimal effects of the otherwise pervasive 1.8-1.9 Ga Svecofennian orogeny. Within this study a new U-Pb baddeleyite age of 2339 +/- 18 Ma has been determined for one of the E-W trending dykes (dyke AD13). The paleomagnetic results show that a strong Svecofennian overprinting is pervasive in the area. Upon thermal or AF demagnetization four remanence directions were obtained. Most typical are the secondary Svecofennian remanence direction A (intermediate down to the NNW) and remanence direction B (intermediate down to the NNE). Component D (D... (More)
- Paleomagnetic results are presented for two Paleoproterozoic mafic dykes in the Taivalkoski area in northern Karelia Province of the Fennoscandian shield where, based on K-Ar data, the crust has seen minimal effects of the otherwise pervasive 1.8-1.9 Ga Svecofennian orogeny. Within this study a new U-Pb baddeleyite age of 2339 +/- 18 Ma has been determined for one of the E-W trending dykes (dyke AD13). The paleomagnetic results show that a strong Svecofennian overprinting is pervasive in the area. Upon thermal or AF demagnetization four remanence directions were obtained. Most typical are the secondary Svecofennian remanence direction A (intermediate down to the NNW) and remanence direction B (intermediate down to the NNE). Component D (D = 115.4 degrees, 1=50.5 degrees, alpha(95) =2.6 degrees) yielding a virtual geomagnetic pole (VGP) D (Plat= -19.5 degrees N, Plon= 263.3 degrees, A95 = 3.1 degrees) is obtained from baked rocks for dyke WD, and based on a positive baked contact test is interpreted to represent the primary magnetization dating from about 2.4 Ga. Dyke AD13 carries only secondary A and B components, its unbaked host migmatites carry reversed A (A(R)) component, and the baked host rock carries a component D' (D = 134.5 degrees, 1= -7.3 degrees, alpha(95) = 8.8 degrees), which yields a VGP pole D' (Plat= -20.4 degrees N, Plon = 257.3 degrees, A(95) = 7.6 degrees), possibly representing magnetization at 2.3 Ga. The new paleomagnetic data from the Karelia Province compared to similar-aged paleomagnetic data from the Superior Province does not support the recently proposed Superia configuration, based upon dyke swarm trajectories. (c) 2013 Elsevier B.V. All rights reserved. (Less)
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https://lup.lub.lu.se/record/4482550
- author
- Salminen, J. ; Halls, H. C. ; Mertanen, S. ; Pesonen, L. J. ; Vuollo, J. and Söderlund, Ulf LU
- organization
- publishing date
- 2014
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Supercontinents, Paleomagnetism, Paleoproterozoic, Superia, Karelia, Mafic dykes
- in
- Precambrian Research
- volume
- 244
- pages
- 87 - 99
- publisher
- Elsevier
- external identifiers
-
- wos:000335106900008
- scopus:84897383151
- ISSN
- 0301-9268
- DOI
- 10.1016/j.precamres.2013.07.011
- language
- English
- LU publication?
- yes
- id
- 6dbca41a-9a1a-4ffa-ac32-6ba2d6a97144 (old id 4482550)
- date added to LUP
- 2016-04-01 10:50:36
- date last changed
- 2022-03-12 17:34:11
@article{6dbca41a-9a1a-4ffa-ac32-6ba2d6a97144,
abstract = {{Paleomagnetic results are presented for two Paleoproterozoic mafic dykes in the Taivalkoski area in northern Karelia Province of the Fennoscandian shield where, based on K-Ar data, the crust has seen minimal effects of the otherwise pervasive 1.8-1.9 Ga Svecofennian orogeny. Within this study a new U-Pb baddeleyite age of 2339 +/- 18 Ma has been determined for one of the E-W trending dykes (dyke AD13). The paleomagnetic results show that a strong Svecofennian overprinting is pervasive in the area. Upon thermal or AF demagnetization four remanence directions were obtained. Most typical are the secondary Svecofennian remanence direction A (intermediate down to the NNW) and remanence direction B (intermediate down to the NNE). Component D (D = 115.4 degrees, 1=50.5 degrees, alpha(95) =2.6 degrees) yielding a virtual geomagnetic pole (VGP) D (Plat= -19.5 degrees N, Plon= 263.3 degrees, A95 = 3.1 degrees) is obtained from baked rocks for dyke WD, and based on a positive baked contact test is interpreted to represent the primary magnetization dating from about 2.4 Ga. Dyke AD13 carries only secondary A and B components, its unbaked host migmatites carry reversed A (A(R)) component, and the baked host rock carries a component D' (D = 134.5 degrees, 1= -7.3 degrees, alpha(95) = 8.8 degrees), which yields a VGP pole D' (Plat= -20.4 degrees N, Plon = 257.3 degrees, A(95) = 7.6 degrees), possibly representing magnetization at 2.3 Ga. The new paleomagnetic data from the Karelia Province compared to similar-aged paleomagnetic data from the Superior Province does not support the recently proposed Superia configuration, based upon dyke swarm trajectories. (c) 2013 Elsevier B.V. All rights reserved.}},
author = {{Salminen, J. and Halls, H. C. and Mertanen, S. and Pesonen, L. J. and Vuollo, J. and Söderlund, Ulf}},
issn = {{0301-9268}},
keywords = {{Supercontinents; Paleomagnetism; Paleoproterozoic; Superia; Karelia; Mafic dykes}},
language = {{eng}},
pages = {{87--99}},
publisher = {{Elsevier}},
series = {{Precambrian Research}},
title = {{Paleomagnetic and geochronological studies on Paleoproterozoic diabase dykes of Karelia, East Finland-Key for testing the Superia supercraton}},
url = {{http://dx.doi.org/10.1016/j.precamres.2013.07.011}},
doi = {{10.1016/j.precamres.2013.07.011}},
volume = {{244}},
year = {{2014}},
}