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dc.contributor.authorSpeedyman, David L.
dc.coverage.spatial20301 Steigen
dc.date.accessioned2020-08-26T09:08:06Z
dc.date.available2020-08-26T09:08:06Z
dc.date.issued1989
dc.identifier.urihttps://hdl.handle.net/11250/2674202
dc.description.abstractSteigen lies geographically within the Uppermost Allochthon, which was emplacedduring the Scandian phase of the Caledonian orogeny. A tectonized boundaryseparates a basement culmination of Precambrian granite-gneisses from youngercover metasediments. The latter comprise marbles, quartzites, amphibolites andpelitic to semipelitic schists, which have been divided informally into fourgroups. Caledonian metamorphism reached a peak in the almandine-amphibolitefacies during the second main deformation phase (D2), with some retrograderecrystallization after D2. An early deformation phase (D1) is indicated by thepreservation of discordant fabrics within porphyroblasts, while the majority offolds are contemporaneous with the formation of the penetrative schistosity(D2). D2 fabrics and fold-axes have been folded into a large D3 antiform whichdeveloped during uprise of the basement geniss culmination late in the orogeny.The granite-gneiss basement exhibits a foliation which is parallel to the base-ment's contact with the metasediments. The geochemistry of the gneisses is verysimilar to that of other basement gneisses in Nordland and to rapakivigranites.The gneisses are considered to be Proterozoic rapakivi granites whichrose diapirically during the Caledonian orogeny, causing updoming anddeformation of the metasediments.
dc.language.isoeng
dc.relation.ispartofseriesNGU Bulletin (414)
dc.rightsNavngivelse 4.0 Internasjonal
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/deed.no
dc.subjectFOLDNING
dc.subjectGNEIS
dc.subjectGRANITT
dc.subjectKALEDONSKE FJELLKJEDE
dc.subjectKARTLEGGING
dc.subjectSTRUKTURGEOLOGI
dc.subjectTEKTONIKK
dc.titleBasement Gneiss doming the Uppermost Allochthon in the Bogøy area of Steigen, Nordland, Norway.
dc.typeJournal article
dc.description.localcode35188
dc.source.pagenumber37-47


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