Percorrer por autor "Prestvik, Tore"
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- The geology, volcanic activity, and age of Bouvetøya, South AtlanticPublication . Prestvik, ToreThe volcanic cone of Bouvetøya is built up of two formations. The older formation, of predominantly pyrodastic rocks which are typically hydrothermally altered, is overlain by a formation of mainly lava flows. The rocks present on the island constitute a transitional volcanic series. K/Ar dating indicates that surface rocks were formed as early as 1.4 Ma B.P. The rocks of Nyrøysa are 0.4-0.5 Ma, showing that this platform, which formed between 1955 and 1958, represents a landslide type deposit rather than a recent eruption as has previously been suggested by several workers. Various kinds of evidence suggest that the volcanic activity, or a cycle of activity, of Bvuvet0ya is now in a declining phase.