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dc.contributor.authorRex, D.C.
dc.contributor.authorRoberts, D.
dc.contributor.authorGuise, P.G.
dc.coverage.spatial24352 Ekkerøy
dc.date.accessioned2020-07-15T08:30:24Z
dc.date.available2020-07-15T08:30:24Z
dc.date.issued1995
dc.identifier.issn0800-3416
dc.identifier.urihttps://hdl.handle.net/11250/2666139
dc.description.abstractPyroxene separates from two dolerite dykes from eastern Varanger Peninsula (at Komagnes and on the island St.Ekkerøya) have been analysed by the 40Ar- 39Ar method. The Komagnes dykes shows steps converging on a 'plateau' with an age of 344+- 17 Ma. The data from the St.Ekkerøya dyke do not yield any conclusive result; a total fusion age of c.640 Ma is shown to be meaningless, and cannot be considered as a crystallisation age for the dyke. The data are compared with results from (1) an earlier K-Ar study and (2) a palaeomagnetic investigation on these same dykes; the former which yielded dates of c.350 Ma, and the latter a loosely Vendian age. The 40Ar-39Ar results have not provided us with any new reliable informationon the age of these dykes which will resolve the conflict between the radiometric and palaeomagnetic 'ages'. The true crystallisation ages of the dykes remain enigmatic. Other isotopic methods may eventuelly help to provide a clearer indication of the true age of these dykes.
dc.language.isoeng
dc.relation.ispartofseriesNGU-Rapport (95.158)
dc.rightsNavngivelse 4.0 Internasjonal
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/deed.no
dc.subjectDATERING
dc.title40Ar-39Ar analyses of pyroxenes from dolerite dykes from southeastern Varanger Peninsula, Finnmark
dc.typeReport
dc.description.localcode34382
dc.source.pagenumber14


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Navngivelse 4.0 Internasjonal
Except where otherwise noted, this item's license is described as Navngivelse 4.0 Internasjonal