Browsing NGU Open Archive by Author "Roberts, David"
Now showing items 61-67 of 67
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The structural and metamorphic history of the Langstrand-Finfjord area, Sørøy, Northern Norway.
Roberts, David (NGU (253), Journal article, 1968)The Langstrand-Finnfjord area of N.E. Sørøy is characterised by a metasedimentary sequence of quartzites, pelitic and semi-pelitic schists and limestones, the stratigraphical order of which can be demonstrated by reference ... -
The terrane concept and the Scandinavian Caledonides
Roberts, David (NGU Bulletin (413), Journal article, 1988)A revised terrane map is presented for the Scandinavian Caledonides, and an outline is given of the principal suspect and exotic terrane-complexes identified outboard from the Baltoscandian miogeocline. The outermost part ... -
U-Pb geochronology and geochemistry of trondhjemites and norite pluton from the SW Trondheim Region, Central Norwegian Caledonides
Nilsen, Odd; Corfu, Fernando; Roberts, David; Sundvoll, Bjørn (NGU Bulletin (441), Journal article, 2003)Zircon analyses from two trondhjemites and a biotite norite from a part of the southwestern Trondheim Region have yielded almost identical Early Silurian ages. The biotite norite and one of the trondhjemites, from a quarry ... -
U-Pb zircon age of a dolerite dyke from near Hamningberg,Varanger Peninsula, North Norway, and its regional significance
Roberts, David; Walker, Nicholas (NGU Bulletin (432), Journal article, 1997)A dolerite dyke cutting very low-grade metasedimentary rocks of the Løkvik- fjellet Group near Hamningberg, NE Varanger Peninsula, Finnmark, has yielded a U-Pb zircon upper intercept age of 567,1 +30\/23 Ma. This ... -
U-Pb zircon age of the Møklevatnet granodiorite, Gjersvik Nappe, Central Norwegian Caledonides
Roberts, David; Tucker, Robert D. (NGU Bulletin (421), Journal article, 1991)The Møklevatnet granodiorite in the Gjersvik Nappe has yielded a U-Pb zircon age of 456 +- 2MA from three, concordant, mulitigrain fractions. This can also be regarded as a maximum age, Early Middle Caradoc, for the oldest ... -
U-Pb zircon ages of a tonalite and a granodiorite dykefrom the southeastern part of the Bindal Batholith,central Norwegian Caledonides
Roberts, David; Gromet, L. Peter; Nissen, August L. (NGU Bulletin (446), Journal article, 2006)An elongate tonalite pluton and a c.10 m-thick granodiorite body in the southeastern part of the Bindal Batholithand Helgeland Nappe Complex, Nord-Trøndelag, have yielded U-Pb zircon ages of 429 \u00B12 and 430 \u00B12 Ma, ... -
Volcanostratigraphy and eruptive products of the Jonsvatn greenstone formation, central Norwegian Caledonides.
Grenne, Tor; Roberts, David (NGU (387), Journal article, 1983)The predominantly volcanic, Ordovician, Jonsvatn greenstone formation comprises appr. 500 m of tholeiitic basalts and associated volcanic products, with interbedded sediments totalling some 100-200 m in thickness. In the ...