Browsing NGU-publikasjoner by Author "Roberts, David"
Now showing items 1-20 of 67
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A likely Early Ordovician age for the regional penetrative cleavage in the Gaissa Nappe Complex.
Sundvoll, Bjørn; Roberts, David (NGU Bulletin (441), Journal article, 2003)Pervasively cleaved mudstones and claystones from two different parts of the Gaissa Nappe Complex in Finnmark wre subjected to Rb-Sr whole-rock analytical investigation. Although neither of the two groups of samples yielded ... -
A tectonostratigraphic transect across the central Scandinavian Caledonides, Storlien - Trondheim - Lepsøy. Part II: Excursion guide in Norway.
Robinson, Peter; Roberts, David (NGU-Rapport (2008.064), Others, 2010)This guidebook was prepared for the Norwegian part (seven days) of Excursion no. 34 ofthe 33\" IGC, Oslo, 2008, to give participants from outside the region as comprehensive a view as possible within 10 days of the ... -
A U-Pb zircon, Archaean age for granitoid rocks in the Kunes Nappe, Laksefjord Nappe Complex, Finnmark, North Norway
Roberts, David; Gromet, L. Peter (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 ... -
Adamsfjord og Ul'lugai'sa. Beskrivelse til de berggrunngeologiske kart 2135 I og 2135 II - M 1:50 000 (med fargetrykt kart).
Chapman, Timothy John; Roberts, David; Føyn, Sven (NGU; Skrifter (381; 40), Journal article, 1983)Descriptions are presented of the different rock-types occurring in either autochthonous or allochthonous position within the confines of these two map-sheets. Five principal geological or tectonostratigraphical elements ... -
Aeromagnetic and gravimetric interpretation of regional structural features in the Caledonides of West Finnmark and North Troms, Northern Norway.
Olesen, Odleiv; Torsvik, Trond H.; Lile, Ole Bernt; Henkel, Herbert; Roberts, David (NGU Bulletin (419), Journal article, 1990)Forkortet.Interpretation of aeromagnetic and gravity data from Finnmark and North Tromshas resulted in a new map of depth to Precambrian basement. The integratedinterpretation of the data shows that the Seiland Igneous ... -
Age determination from the Trondheim Region Caledonides, Norway: a preliminary report.
Roberts, David; Wolff, Fredrik Chr.; Wilson, M. R. (NGU (288), Journal article, 1973)Twenty-four potassium-argon age determinations have been made on metamorphic minerals and whole-rocks (phyllites) from the Caledonides of the Trondheim region, Norway. Nineteen of the apparent ages fall between 438 and 402 ... -
Barents Sea Aeromagnetic Remapping BASAR-08 – Acquisition, processing and interpretation
Brönner, Marco; Koziel, Janusz; Barrère, Cecile; Roberts, David; Olesen, Odleiv; Ebbing, Jörg; Gernigon, Laurent (NGU-Rapport (2009.020), Report, 2009)A high sensitivity aeromagnetic survey, BASAR-08, was carried out in an area of 80,600 km2 in the Norwegian Barents Sea. Data processing comprised spike-removal and data editing, systematic corrections, statistical, and ... -
Bedrock Geology of the Porsanger - Tana Region, Finnmark: An Excursion Guide.
Roberts, David; Siedlecka, Anna (NGU-Rapport (92.317), Report, 1992)Thirty-one selected localities are brefly described along a traverse fromPorsangerfjorden to Tanafjorden. The localities provide a general impressionof representative rock types and their deformation in the Gaissa and ... -
Berlevåg. Berggrunnskart; Berlevåg; 23361; 1:50 000; Revidert foreløpig utgave
Roberts, David (Map, 2009) -
Brittle deformation history of fault rocks on the Fosen Peninsula, Trøndelag, Central Norway.
Grønlie, Arne; Roberts, David; Nilsen, Bjørn (NGU Bulletin (421), Journal article, 1991)Late and post-Caledonian fault deformation of rock units on the Fosen Peninsula follows a time sequence wherein lower crustal ductile deformation was followed by several episodes of brittle fragmentation, some with coeval ... -
Caledonian and Baikalian tectonic structures on Varanger Peninsula, Finnmark, Norway, and coastal areas of Kola Peninsula, NW Russia
Roberts, David (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 ... -
Contemporary stress orientation features in bedrock, Trøndelag, central Norway, and some regional implications.
Roberts, David; Myrvang, Arne (NGU Bulletin (442), Journal article, 2004)Based on in situ rock stress measurements and contemporary stress orientation structures observed at diverse sites in Trøndelag, it can be shown that the Møre-Trøndelag Fault Complex marks an important structural divide ... -
Coop Phase 2 Crustal Onshore-Offshore Project
Olesen, Odleiv; Baranwal, Vikas; Brönner, Marco; Dalsegg, Einar; Dumais, Marie-Andrée; Gellein, Jomar; Gernigon, Laurent; Heldal, Tom; Larsen, Bjørn Eskil; Lauritsen, Torleif; Lutro, Ole; Maystrenko, Yuriy; Nasuti, Aziz; Roberts, David; Rueslåtten, Håkon; Rønning, Jan Steinar; Slagstad, Trond; Solli, Arne; Stampolidis, Alexandros (NGU-Rapport (2015.063), Report, 2015)The Crustal Onshore-Offshore Project (Coop) is an integrated mapping and research project established to study the onshore-offshore relationships in the northeastern North Sea and Mid Norway. The Coop Phase 2 Report ... -
Depositional environment and apparent age of the Fauske carbonate conglomerate, North Norwegian Caledonides.
Heldal, Tom; Fallick, Anthony E.; Gorokhov, Igor M.; Roberts, David; Melezhik, Victor A. (NGU Bulletin (436), Journal article, 2000)The Fauske conglomerate represents a rather rare case of a monomict carbonate conglomerate in the Late Neoproterozoic to Silurian, lithostratigraphic successions of the Norwegian Caledonides. Lithological varieties of this ... -
Devonian ages from 40 Ar/39Ar dating of plagioclase in dolerite dykes, eastern Varanger Peninsula, North Norway.
Guise, Philip G.; Roberts, David (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 ... -
Devonian tectonic deformation in the Norwegian Caledonides and its regional perspectives.
Roberts, David (NGU (380), Journal article, 1983)Late-Caledonian megascopic folds deforming the Old Red Sandstone sequences of southern Norway are mostly synclines of E-W to NE-SW trend and E to NE plunge. Thrusts along the eastern and southern margins of several ORS ... -
Disparate geochemical patterns from Snåsavatn greenstone, Nord-Trøndelag, Central Norway.
Roberts, David (NGU (373), Journal article, 1982)Greenstone volcanites of Middle Ordovician age from the Snåsavatn area of the Central Norwegian Caledonides can be divided into two distinctive groups on the basis of their geochemical patterns. The bulk of the lavas sampled ... -
Early Ordovician ages of zircons from felsic rocks and a conglomerate clast, Frosta peninsula, Central Norwegian Caledonides
Gromet, L. Peter; Roberts, David (NGU Bulletin (450), Journal article, 2010)Zircons extracted from a felsic sheet in the bimodal, magmatic, Fånes complex of the Støren Nappe on Frosta peninsula yielded a U-Pb age of 488 \u00B1 5 Ma, interpreted as the age of crystallisation. A large clast of ... -
Finnmark fylke. Berggrunnsgeologi Finnmark fylke M 1:500 000; trykt i farger
Roberts, David; Siedlecka, Anna (Map, 1996)Beskrivelsen finnes på kartet. -
Geochemical changes accompanying mylonitisation of granite at the base of the Helgeland Nappe Complex, Nord-Trøndelag, central Norway
Roberts, David; Nissen, August L. (NGU Bulletin (446), Journal article, 2006)A progressive conversion of megacrystic granite into mylonites at the base of the Helgeland Nappe Complex in the Caledonides of central Norway is reflected in microstructural, textural and modal changes. These mylonites ...