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Cambrian sediments and Proterozoic granites in the Dividalen-Tometrdsk area, northern Scandinavia: Palaeomagnetism and U-Pb geochronology

Rehnström, Emma LU and Torsvik, TH (2003) In GFF 125(3). p.131-138
Abstract
New palaeomagnetic data from the autochthonous Early Cambrian Dividal Group (northern Scandinavia) confirm earlier findings, and a refined palaeomagnetic pole of 58.4degreesN and 122.5degreesE, places Baltica at intermediate southerly latitudes at similar to535 Ma. Palaeomagnetic data from the immediately underlying granitic basement (pole: 9.8degreesN, 226.7degreesE) differ markedly from the Dividal sediments. The result of this fieldtest increases the palaeomagnetic reliability of the Dividal Group results. We dated the granitic basement in the eastern part of the Tornetrask area (corresponding to our palaeomagnetic site) to 1786+/-4 Ma (U-Pb zircon and titanite), whilst deformed allochthonous granites west of lake Tornetrask are... (More)
New palaeomagnetic data from the autochthonous Early Cambrian Dividal Group (northern Scandinavia) confirm earlier findings, and a refined palaeomagnetic pole of 58.4degreesN and 122.5degreesE, places Baltica at intermediate southerly latitudes at similar to535 Ma. Palaeomagnetic data from the immediately underlying granitic basement (pole: 9.8degreesN, 226.7degreesE) differ markedly from the Dividal sediments. The result of this fieldtest increases the palaeomagnetic reliability of the Dividal Group results. We dated the granitic basement in the eastern part of the Tornetrask area (corresponding to our palaeomagnetic site) to 1786+/-4 Ma (U-Pb zircon and titanite), whilst deformed allochthonous granites west of lake Tornetrask are slightly older (1800+/-4 Ma; U-Pb zircon). These ages are compatible with autochthonous basement ages to the east of the study area, but also with ages from basement windows to the west. Preliminary palaeomagnetic data from the 1786+/-4 Ma granitic basement are clearly pre-Phanerozoic in origin, and comparable and concordant zircon and titanite ages may hint that the magnetisation could be primary. However, the palaeomagnetic pole does not match contemporaneous poles from Baltica, which suggest a tectonic explanation (no palaeohorizontal control), a problem of secular variation (only one site) or a younger but pre-Phanerozoic remagnetisation event, which did not affect the U-Pb system in zircon and titanite. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Baltica apparent polar wander path, geochronology, Proterozoic granites, Cambrian sediments, palaeomagnetism, palaeogeography
in
GFF
volume
125
issue
3
pages
131 - 138
publisher
Geological Society of Sweden
external identifiers
  • wos:000186251500002
ISSN
2000-0863
language
English
LU publication?
yes
id
3125eb33-0883-4d7c-a41d-1fbcc6d64135 (old id 297269)
alternative location
http://www.gff-online.se/site/article.asp?articleID=734
date added to LUP
2007-09-20 12:28:35
date last changed
2016-04-15 18:37:55
@article{3125eb33-0883-4d7c-a41d-1fbcc6d64135,
  abstract     = {New palaeomagnetic data from the autochthonous Early Cambrian Dividal Group (northern Scandinavia) confirm earlier findings, and a refined palaeomagnetic pole of 58.4degreesN and 122.5degreesE, places Baltica at intermediate southerly latitudes at similar to535 Ma. Palaeomagnetic data from the immediately underlying granitic basement (pole: 9.8degreesN, 226.7degreesE) differ markedly from the Dividal sediments. The result of this fieldtest increases the palaeomagnetic reliability of the Dividal Group results. We dated the granitic basement in the eastern part of the Tornetrask area (corresponding to our palaeomagnetic site) to 1786+/-4 Ma (U-Pb zircon and titanite), whilst deformed allochthonous granites west of lake Tornetrask are slightly older (1800+/-4 Ma; U-Pb zircon). These ages are compatible with autochthonous basement ages to the east of the study area, but also with ages from basement windows to the west. Preliminary palaeomagnetic data from the 1786+/-4 Ma granitic basement are clearly pre-Phanerozoic in origin, and comparable and concordant zircon and titanite ages may hint that the magnetisation could be primary. However, the palaeomagnetic pole does not match contemporaneous poles from Baltica, which suggest a tectonic explanation (no palaeohorizontal control), a problem of secular variation (only one site) or a younger but pre-Phanerozoic remagnetisation event, which did not affect the U-Pb system in zircon and titanite.},
  author       = {Rehnström, Emma and Torsvik, TH},
  issn         = {2000-0863},
  keyword      = {Baltica apparent polar wander path,geochronology,Proterozoic granites,Cambrian sediments,palaeomagnetism,palaeogeography},
  language     = {eng},
  number       = {3},
  pages        = {131--138},
  publisher    = {Geological Society of Sweden},
  series       = {GFF},
  title        = {Cambrian sediments and Proterozoic granites in the Dividalen-Tometrdsk area, northern Scandinavia: Palaeomagnetism and U-Pb geochronology},
  volume       = {125},
  year         = {2003},
}