Undersøkelser over norske lerer IV. Norske lerforekomster: B. Møre Sør-Trøndelag, Nord-Trøndelag, delvis Nordland samt resterende del av Akershus, Hedmark og Buskerud fylker.

Abstract

The present paper is a sequel to the \"Norwegian Clay Deposits A\". Statens Raa- stofskomites Publikation No. 16 (The State Raw Material Commitee Publication No. 16) by the same author and is chiefly a description of the occurence of samples of clay collected during the summer of 1923. In Northern Norway the brick-making industry is less extended than in the districts described in the foregoing paper. In order to obtain a more extensive representation of existing clays, samples were taken, not only from the clay pits at brick fields, but also from clay deposits made accessible by the landslides and slips, that frequently occur in the Trøndelag district. In his introduction, the author points aout that the northernclys on the whole consits of a coarser material than the deposits in the south of the couuntry, and he presumes the cause of this to be that the material in the north has not suffered so many re-sedimentations. Beside mechanical sorting, the clay material suffers chemical changes when constantly under the influence of a large surplus of water. The author points out that there exists a connection between the moranic masses found within the draining districts of a river system and the marine clay deposits occurring at the bottom of the valley.