THE CALEDONIAN SEQUENCE IN NY FRIESLAND, SPITSBERGEN

Abstract

Arising mainly out of observations in the last decade the structure of the Ny Friesland sector of Spitsbergen is outlined for the first time and summarized in a map and sections. It is interpreted as reflecting the formation of a geosyncline of Hecla Hoek rocks (late Pre-Cambrian to mid-Ordovician), and their deformation in the Ny Friesland orogeny, with the formation of gneisses and with the emplacement of “post-tectonic” batholiths, followed by Old Red Sandstone deposition and deformation in the Svalbard folding. Thus a mobile history (the Caledonian sequence) stretches from late Pre-Cambrian to Upper Devonian times and reaches its climax in the Ny Friesland orogeny (between mid-Ordovician and late Silurian) and the structures arising therefrom form the core of this paper as they do of the region itself. The sequence is compared with that in other areas, particularly East Greenland.