KRZYSZTOF BIRKENMAJER

• Main Authors: Caledonides Of Svalbard, Plate Tectonics
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Svalbard; Hoek; Ny Friesland; Birkenmajer; Spitsbergen
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.573.960; http://2dgf.dk/xpdf/bull24-01-02-1-19.pdf

The Caledonian fold belt of Svalbard (Spitsbergen) representing the northern extremity Cj of the circum-Atlantic Caledonian mountain system comprises between 15 and 20 km of sediments and metasediments with a variable share of volcanics and metavolcanics (Hecla Hoek succession). The main phase of Caledonian deformation and metamorphism occurred during the late Ordovician Ny Friesland orogeny and was followed by late-orogenic mig-matisation and plutonism around the boundary of Silurian and Devonian and by late-orogenic deformations involving plate motions during the Devonian. An attempt is being made to evaluate the role of pre-Caledonian metamorphism and diastrophism using evidence from isotopic age determinations and from Precambnan unconformities so far generally neglected or underestimated in reconstructions of the evolution of the Hecla Hoek geosyncline. Three successive geosynclinal basins are analysed, the Precambrian Torellian (eugeosynclinal) and Jarlsbergian (miogeosynclinal) basins and the Early Palaeozoic Horn-sundian (miogeosynclinal) basin. Diastrophic events recognised in the Precambrian column of the Hecla Hoek are tentatively correlated with igneous activity and metamorphic events within Svalbard and elsewhere.