Undersøkelser av steinfraksjonens rundingsgrad i glasigene jordarter.

Abstract

The main bulk of the stone material in Norway has undergone only one or a few transport phases. A classification has been made for the deposits in the interior of Eastern Norway on the basis of the degree of roundness of pebbles (2-6 cm), and the petrographical composition. The degree of roundness has been found to be dependent on mode and length of transport. Ordinary till contains less than 10 % rounded particles. Glaciofluvial material contains less than 20 % of rounded material after a supra- or en-glacial transport. Subglacial and normal fluvial transport rapidly increases the degree of roundness. In these deposits more than 50 % of the particles are rounded.