Browsing NGU-publikasjoner by Author "Roberts, David"
Now showing items 41-60 of 67
-
Mafic dykes in the Lkesdal Nappe at Sørli, Central Norwegain Caledonides: geochemistry and palaeotetonic implications
Beckholmen, Monica; Roberts, David (NGU Bulletin (435), Journal article, 1999)Mafic dykes intruding feldspathic metasandstones of the Leksdal (Sarv) Nappe in the Sørli district of Nord-Trøndelag, Central Norway, vary from weakly foliated, porphyritic types to more common, strongly schistose, sparsely ... -
Neotectonic studies in Finnmark 1992
Olesen, Odleiv; Olsen, Lars; Roberts, David (NGU-Rapport (92.325), Report, 1992)The postglacial Stuoragurra Fault (SF) lies within the regional Mierujav'ri- Sværholt Fault Zone which is located in the extensive Proterozoic terrain of inner Finnmark. To explore the SF at depth, 135 m of core-drilling ... -
New data on Upper Ordovician conodonts from theTrondheim Region, Central Norwegian Caledonides
Tolmacheva, T. Ju; Roberts, David (NGU Bulletin (447), Journal article, 2007)A small collection of Upper Ordovician (Early-Mid Katian) conodonts has been recovered from low-grade meta-limestones in the K\u00F6li Nappes of the Upper Allochthon of the Trondheim Region, central Norway. For the Snåsavatnet ... -
Ordovician lithistid sponges and gastropods from the Snåsa limestone, Nord-Trøndelag, Norway
Roberts, David (NGU Bulletin (434), Journal article, 1998)Fossil occurring in the Snåsa Limestone, observed in new road-cuts along the main E6 road near Snåsavatnet, Nord-Trøndelag, are illustrated and briefly described. Although the effects of Scandian deformation and crystallisation ... -
Petrochemistry and palaegeographic setting of the Ordovician volcanic rocks of Smøla, Sentral Norway.
Roberts, David (NGU (359), Journal article, 1980)The Arenig-Llanvirn volcanic rocks of Smøla are distinctly calc-alkaline in their chemistry. The palaographic setting focuses attention on certain problems regarding lithostratigraphic correlation within the now fragmented ... -
Petroleum geology and geology of the North Sea and Northeast Atlantic Continental Margin. Proceedings of a conference held at the University of Bergen 1973
Whiteman, Arthur; Sellevoll, Markvard A.; Roberts, David (NGU (316), Journal article, 1975) -
Possible Mesozoic sediments in fault and breccation zones in Frøyfjorden, Mid Norway
Bøe, Reidulv; Vigran, Jorunn Os; Roberts, David; Mørk, Mai Britt E. (NGU Bulletin (443), Journal article, 2005)The 5.3 km long Frøya Tunnel beneath Frøyfjorden, Central Norway, links the islands of Hitra and Frøya and passes through a major zone of faulting and breccation which parallels the Møre-Trøndelag Fault Complex. Faults and ... -
Provenance and sediment routing of Neoproterozoic formations on the Varanger, Nordkinn, Rybachi and Sredni peninsulas, North Norway and Northwest Russia: a review
Roberts, David; Siedlecka, Anna (NGU Bulletin (452), Journal article, 2012)Provenances and sediment routing of Neoproterozoic, mainly low-grade, sedimentary successions on four large peninsulas in Northeast Norway (Varanger and Nordkinn) and Northwest Russia (Rybachi and Sredni) have been assessed ... -
Rb-Sr dating of cleaved mudstones from eastern and western parts of the Gaissa Nappe Complex, Finnmark
Roberts, David; Sundvoll, Bjørn (NGU-Rapport (2002.110), Report, 2002)Samples of pervasively cleaved mudstones and claystones from two different parts of the Gaissa Nappe Complex in Finnmark were subjected to Rb-Sr analytical investigation with the aim of trying to dtermine the metamorphic ... -
Report from a visit to the Komi Branch of the Russian Academy of Sciences in Syktyvkar, Russia, and from fieldwork in the central Timans, August 1995
Siedlecka, Anna; Roberts, David (NGU-Rapport (95.149), Report, 1995)The objective of research initiated in Central Timans in August 1995 was to extend and continue the work carried out in the Varanger-Rybachi-Sredni-Kildin area during the years 1990-93. The studies embraced stratigraphy, ... -
Samtolking av geodata i Grongfeltet - status pr. 15.12.94
Dalsegg, Einar; Dyrstad, Geir Ståle; Solli, Arne; Roberts, David; Reinsbakken, Arne; Meyer, Gurli B.; Heim, Michael; Grenne, Tor; Elvebakk, Harald; Sandstad, Jan Sverre (NGU-Rapport (94.094), Report, 1994)Rapporten oppsummerer undersøkelsene som er utført innenfor prosjektet \"Samtolkning av geodata i Grongfeltet\" under feltsesongen 1994 og de fore- løpige resultatene fra disse er gitt. Oppfølgende undersøkelser var på ... -
Scientific research exchange programme on the Upper Proterozoic geology of the Varanger Peninsula, Rybachi and Sredni Peninsula, Kildin Island, Bolshoi Aynov and Malyi Aynov Islands. Report from the joint fieldwork on the Norwegian and Russian sides
Siedlecka. Anna; Predovsky, A.; Negrutsa, V.; Lyubtsov, V.; Torsvik, Trond; Roberts, David (NGU-Rapport (92.321), Report, 1991)The 1991 fieldwork in this project was a continuation of investigations commenced in 1990. The Norwegian and Russian workers agreed that: (1) The Trollfjorden-Komagelva Fault Zone continues from the Varanger Peninsula to ... -
Scientific research programme on the Upper Proterozoic geology of the Varanger Peninsula, Rybachi and Sredni Peninsulas, Kildin Island, Bolshoi Aynov and Malyi Aynov Islands. Report from the joint field- work on the Norwegian and Russian sides of th
Siedlecka, Anna; Negrutsa, V.; Lyubtsov, V.; Roberts, David (NGU-Rapport (92.320), Report, 1990)Stratigraphic sections and key localities were examined on both sides of the national border during this first season of the international collaboration. During fieldwork on Varanger Peninsula the Russian workers concentrated ... -
Sedimentary, tectonic and metamorphic features of the Devonian of Røragen, Sør-Trøndelag.
Roberts, David (NGU (311), Journal article, 1974)An outline is given of the depositional environment of these Lower Devonian rocks following the discovery of various primary sedimentary structures which have provided some evidence of palaeocurrent directions. Tectonic ... -
Some features of tectonic deformation of Old Red Sandstone sediments on Hitra, west central Norway.
Roberts, David (NGU (370), Journal article, 1981)Minor tectonic structures affecting Downtonian Old Red Sandstone sediments on Hitra indclude folds parasitic to a major syncline, and an associated axial surface spaced cleavage. The cleavage is most prominent in mudstones, ... -
Structural observations from the Kopperå-Riksgrense area and discussi- on of the tectonics of Stjørdalen and the N.E. Trondheim region.
Roberts, David (NGU (245), Journal article, 1967)Minor tectonic structures occurring in weakly metamorphosed Hovin and Horg Group sediments along Tevedalen, east of Meråker, are described in the first part of the paper. Three episodes of folding are recognized, the ... -
Tectonic features of an area N.E. of Hegra, Nord-Trøndelag, and their regional significance - preliminary notes.
Roberts, David (NGU (255), Journal article, 1968)Following brief notes on the low-grade metasediments occuring in the area near Hegra, 50 km east of Trondheim, the types of structures associated with three episodes of deformation of main Caledonian (Silurian) age are ... -
Tectonostratigraphic succession and development of the Finnmarkian nappe sequence, North Norway.
Zwaan, Klaas B.; Roberts, David (NGU (343), Journal article, 1978)Detailed investigations of the Finnmarkian nappe sequence within the 1:250 000 map-sheets \"Hammerfest\", \"Nordreisa\" and \"Honningsvåg\" have revealed a complex construction of discrete nappes, sub-nappes and minor ... -
The Caledonian fold belt i Finnmark
Roberts, David (NGU Bulletin (403), Journal article, 1985)Forkortet. The Caledonian allochthon in Finnmark embraces 4 major nappes or nappe complexes named, from bottom to top, the Gaissa, Laksefjord, Kalak and Magerøy. Of these the 3 lower nappe complexes acquired their internal ... -
The Raudfjellet ophiolite fragment, Central Norwegian Caledonides: principal lithological and structural features.
Roberts, David; Nilsson, Lars Petter; Ramsay, Donald M. (NGU Bulletin (445), Journal article, 2005)The Raudfjellet complex, Nord-Trøndelag, displays several of the features of a classical ophiolite pseudostratigraphy. At its base is a spectacular ultramafic mylonite. Elements represented include: (1) Ultramafic rocks, ...