Mesoproterozoic geomagnetic reversal asymmetry in light of new paleomagnetic and geochronological data for the Häme dyke swarm, Finland : Implications for the Nuna supercontinent

Show simple item record

dc.contributor.author Salminen, Marja Johanna
dc.contributor.author Klein, Robert
dc.contributor.author Veikkolainen, Toni Henri Kristian
dc.contributor.author Mertanen, Satu
dc.contributor.author Mänttäri, Irmeli
dc.date.accessioned 2020-01-09T12:16:01Z
dc.date.available 2020-01-09T12:16:01Z
dc.date.issued 2017-01
dc.identifier.citation Salminen , M J , Klein , R , Veikkolainen , T H K , Mertanen , S & Mänttäri , I 2017 , ' Mesoproterozoic geomagnetic reversal asymmetry in light of new paleomagnetic and geochronological data for the Häme dyke swarm, Finland : Implications for the Nuna supercontinent ' , Precambrian Research , vol. 288 , pp. 1-22 . https://doi.org/10.1016/j.precamres.2016.11.003
dc.identifier.other PURE: 72652945
dc.identifier.other PURE UUID: cfe27950-e480-4d12-846c-587d9d45e1a9
dc.identifier.other WOS: 000392555900001
dc.identifier.other Scopus: 85000933234
dc.identifier.other ORCID: /0000-0001-5347-1920/work/30029864
dc.identifier.other ORCID: /0000-0003-2740-6185/work/30030707
dc.identifier.uri http://hdl.handle.net/10138/309172
dc.description.abstract Baltica represents one of the key continents of the Mesoproterozoic supercontinent Nuna forming the core of it together with Laurentia and Siberia. This study presents new geochronological and paleomagnetic data obtained for Häme diabase dyke swarm in southern Finland. New U-Pb (baddeleyite) ages 1642 ± 2 Ma and 1647 ± 14 Ma for two reversely magnetized dykes are acquired. Demagnetization revealed a dual polarity remanent magnetization direction carried by magnetite. The combined normal (N) and reversed (R) polarity direction for 11 dykes (=sites) is D = 355.6°, I = -09.1° (k = 8.6 and α95 = 16.6°) yielding a paleomagnetic pole at 23.6°N, 209.8°E (K = 10.6 and A95 = 14.7°) with Van der Voo value Q = 7. N and R magnetized units for the Häme dyke swarm show asymmetry in declination values, probably caused by an age difference between the dykes. The Geocentric Axial Dipole (GAD) model indicates that all geomagnetic reversals should be symmetric (in inclination), yet it has been noted that this is not always the case (e.g. 1.57 Ga Satakunta and Åland dykes in Baltica). By analyzing global dual polarity paleomagnetic data we show that the GAD model is a valid assumption at 1.7 – 1.4 Ga and that the asymmetry between some normal and reversed polarities in global dual-polarity data sets appears randomly over time, and does not follow a global trend. Further, we show that in the case of Åland and Satakunta dykes an unremoved secondary magnetization component could explain the obtained asymmetry. GAD assumption is used to reconstruct the core of Nuna on equatorial latitudes using new data for Häme dykes. Paleomagnetic evidence suggest that maximum assembly of Nuna occurred at 1.5 Ga and the dispersal of the core is proposed to be associated with coeval 1.38 – 1.27 Ga magmatism in its core continents. en
dc.format.extent 22
dc.language.iso eng
dc.relation.ispartof Precambrian Research
dc.rights cc_by_nc_nd
dc.rights.uri info:eu-repo/semantics/openAccess
dc.subject 114 Physical sciences
dc.subject 1171 Geosciences
dc.title Mesoproterozoic geomagnetic reversal asymmetry in light of new paleomagnetic and geochronological data for the Häme dyke swarm, Finland : Implications for the Nuna supercontinent en
dc.type Article
dc.contributor.organization Department of Physics
dc.description.reviewstatus Peer reviewed
dc.relation.doi https://doi.org/10.1016/j.precamres.2016.11.003
dc.relation.issn 0301-9268
dc.rights.accesslevel openAccess
dc.type.version acceptedVersion

Files in this item

Total number of downloads: Loading...

Files Size Format View
salminen_et_al_2016.pdf 4.478Mb PDF View/Open

This item appears in the following Collection(s)

Show simple item record