Rundingens og petrografiens innflytelse på sprøhet og flisighet av naturlige grusforekomster, belyst ved eksempler fra noen norske dalfører.

Abstract

Gravel deposits in five Norwegian valleys have been investigated with regard to petrographic composition, roundness, transport directions, brittleness and flakiness. These prarameters are all found to be very complex. However, the brittleness and flakiness along Surnadalen are more consistent in the fluvial than in the glacifluvial material, but this is not the case in Suldalen. The glacifluvial material is normally less rounded than the fluvial, which is however influenced by the petrographic composition of the gravel, but perhaps more by the roundness. This latter is presumably due not only to enrichment of the strongest particles by continued fluvial treatment, but also to the roundness itself.