Abstract:

SUMMARY: Quartzose sediments from the Lower Palaeozoic orogen of Svalbard have suffered metamorphism to low grade (6 kb and a maximum of 500°C). Studies of the deformed micro-structures of these rocks reveal that pressure solution and intracrystalline deformation mechanisms are the major processes by which deformation occurs. The dominant mechanism for any given lithology (at approximately the above conditions of pressure and temperature) appears to depend on the rock composition. Quartzose rocks containing micaceous and other ‘impurities’ tend to deform by pressure solution, those containing little or no other material apart from quartz tend to deform by intracrystalline deformation mechanisms.