Blar i Artikler på emneord "DATERING"
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A new Rb-Sr isotopic parameter for metasomatism, At, and its application in study of pluri-fenitized gneisses around the Fen ring complex.
(NGU Bulletin (445), Journal article, 2005)Emplacement of the Fen peralkaline-carbonatitic ring complex 583 Ma ago in the c. 1105 Ma old Telemark gneisses caused mineralogical, chemical and Sr-isotopic changes, i.e., fenitization, in the country rocks. Fenitization ... -
A possible basement to the Mesoproterozoic quartzites on Hardangervidda, South-Central Norway: zircon U-Pb geochronology of a migmatitic gneiss
(NGU Bulletin (437), Journal article, 2000)On Hardangrvidda west of the Mandal-Ustaoset fault zone in South Norway, some 80-90% of the crust consists of orthogneisses and foliated and massive granites in this plutonic environment the Mesoproterozoic quartzites of ... -
A proposed deglaciation chronology for the Trondheimsfjord area, Central Norway.
(NGU (373), Journal article, 1982)Radiocarbon datings of the deglaciation of the Trondheimsfjord area strongly suggest that the coastal areas and the outer part of the fjord were deglaciated before 11000 B.P. During early Younger Dryas the inland ice ... -
A U-Pb zircon, Archaean age for granitoid rocks in the Kunes Nappe, Laksefjord Nappe Complex, Finnmark, North Norway
(NGU Bulletin (449), Journal article, 2009)Nappes in the middle parts of the Caledonian tectonostratigraphy in Finnmark, northern Norway, contain slices of granitoid basement that hitherto have not been reliably dated. Zircons extracted from two, high-K, calc-alkaline ... -
Age of the Krossnes Granite, West Norway
(NGU Bulletin (413), Journal article, 1988)Rb-Sr isotope whole-rock dating of the Krossnes Granite has yielded an isochron age of 430 \u00B1 6 Ma with I.R. = 0.07066 \u00B1 0.0005, interpreted as the age of intrusion. This age is close to that of the Håkre Granite ... -
Age of the Younger Dryas ice-marginal substages in Mid-Norway - Tautra and Hoklingen, based on a compilation of 14C-dates
(NGU Bulletin (454), Journal article, 2015)The ice-marginal Tautra and Hoklingen Substages in the Trøndelag counties, Mid-Norway, have for a long time been referred to as of early and late Younger Dryas (YD) age, respectively. The basis for this is the regional ... -
Benthic foraminiferal evidence of environmental change in the Skagerrak over the past six decades
(NGU Bulletin (430), Journal article, 1996)High resolution analyses of fossil benthic forminiferal assemblages have been performed on two short (<40cm) sediment cores from the deep Skagerrak Basin, NE North Sea. 210 Pb-datings of replicate cores from the same two ... -
Caledonian and Baikalian tectonic structures on Varanger Peninsula, Finnmark, Norway, and coastal areas of Kola Peninsula, NW Russia
(NGU Bulletin (431), Journal article, 1996)Based on data compiled from biostratigraphy, radiometric dating and palaeomag- netic studies, contractional deformation and low-grade metamorphism in the Neo- proterozoic to earliest Palaeozoic successions of coastal areas ... -
Carbonate sand deposition along the coast of southern Norway
(NGU Bulletin (427), Journal article, 1995) -
Chemical (U-Th-Pb) dating of monazite: Analytical protocol for a LEO 1450VP scanning electron microscope and examples from Rogaland and Finnmark, Norway
(NGU Bulletin (446), Journal article, 2006)Monazite is a common accessory mineral and is a valuable mineral chronometer on account of its relatively high U and Th contents, negligible common Pb, and a high closure temperature. Because all the Pb present in monazite ... -
Composition of metamorphic rocks and some aspects of evolution of the Lapland Granulite Belt on the Kola Peninsula, USSR
(NGU Bulletin (421), Journal article, 1991)Combined geological and petrochemical data suggest that the Lapland Granulite Belt can be divided into a lower sedimentary-volcanic unit and an upper, predominantly sedimentary sequence. Metamorphic rocks from the lower ... -
Devonian ages from 40 Ar/39Ar dating of plagioclase in dolerite dykes, eastern Varanger Peninsula, North Norway.
(NGU Bulletin (440), Journal article, 2002)Gas-release spectra derived from the analysis of plagioclase from three geographically distinct but geochemically comparable dolerite dykes from the eastern part of Varanger Peninsula, northern Norway, show similar features ... -
From Archaean to Proterozoic on Hardangervidda, south Norway
(NGU Bulletin (433), Journal article, 1997) -
Geochemistry and Rb-Sr isochron age of trondhjemite dykes from the Gula Complex, near Snøan, Central Norway.
(NGU Bulletin (437), Journal article, 2000)Trondhjemite dykes trending c.ENE-WSW and transecting early metamorphic fabrics in rocks of the Gula Complex south-southwest of Støren, are themselves weakly metamorphosed and foliate. Geochemical data show that the dykes ... -
Geological note: Age of the Hamningberg dolerite dyke, Varanger Peninsula, Finnmark: Devonian rather than Vendian - a revised enterpretation
(NGU Bulletin (451), Journal article, 2011)In an earlier geochronology paper in this same journal, discordant U-Pb ages on zircons from a dolerite dyke near Hamningberg, Varanger Peninsula, Finnmark, were interpreted to favour a Vendian (Ediacaran) age of intrusion ... -
Geology and structural evolution of the Precambrian rocks of the Oslofjord - Øyeren area, Southeast Norway.
(NGU Bulletin (398), Journal article, 1984)The area (1200 km\u00B2) described covers the northern part of a major thrust segment in the eastern subprovince of the Sveonorwegian orogenic belt along the southwestern margin of the Baltic Shield. The oldest rock unit ... -
Geology of the southern part of the Kautokeino Greenstone Belt: Rb-Sr geochronology and geochemistry of associated gneisses and late intrusions.
(NGU Bulletin (403), Journal article, 1985)The southern part of the Kautokeino Greenstone Belt is divided into four volcanic formations separated by sedimentary units. The formation represent a development from Archaean komatiitic sequences to Middle Proterozoic ... -
Glacial geology,deglacition chronology and sea-level changes in the southern Telemark and Vestfold counties, Southeastern Norway
(NGU Bulletin (435), Journal article, 1999)A revised and more detailed deglaciation chronology is presented in the soputhern Telemark and Vestfold, southeastern Norway, based mainly on information and results from mapping projects on the superficial deposits carried ... -
Implication of isotope data on the metamorphism of the basic volcanites from the Sjangeli Window, northern Sweden
(NGU Bulletin (415), Journal article, 1989)The Lower Proterozoic supracrustal rocks of the Sjangeli area form an approximately N-S striking belt. The supracrustal belt consists of three metamorphosed volcanic and volcanosedimentary units, which are intercalated ... -
Isotopic age determinations in South Norway: II. The problem of errorchron ages from Telemark rhyolites.
(NGU Bulletin (418), Journal article, 1990)Two sets of Telemark Supracrustal acid metavolcanics of the Rjukan Group were investigated by the Rb-Sr whole-rock method. Eleven smples within a sampling range of about 10 m were taken at Kvamsstøl at a distance of about ...