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Abstract

In this paper has been given a brief statement of the character of our marine clay to an extent considered important for the study of clay as a foundation for building. Our marine clay chiefly consists of fragments of rockforming minerals. Partly it was deposited direct from mud-bearing glacier rivers in the cold ocean water of the fjords during the melting stage of the Ice age. Part of it has, however, been redeposited, consisting of mud from higher situated terraces of the Ice age which during a later period has been carried away by the rivers and deposited anew. Clay occurs at all altitudes between the highest shore-lines and the bottom of the fjords. Layers of clay are alternating with beds of sand, and the total thickness of the accumulations is more than 100 m. Within the clay can sometimes be found beds of gravel as well as stray boulders carried along by drifting ice-bergs. The fossils occurring show the existence as well of a glacial as of a post-glacial clay. K.O. Bjørlykke has carried out numerous elutriation tests, which show that clay containing more than 50 per cent of grains less than 0.002 mm rarely occurs in our country. Sometimes, however, clay which according to Atterberg belongs to \"the very stiff clays\", has been found.