Oplysninger til Blakstads jordbundskart over Trondhjems omegn

Abstract

Forkortet: Most of the area represented on the map consists of marine clay which is left white on the map p.113. The finely striated parts are sandy clay and the finely dotted parts are sand. River gravel is designated with heavier dots, moraine (at one place to the East of the town) with small circles. Artificial terrain is found in the town along the sea. The solid rock, which is vertically striated on the map consist chefly of green chloritiferous hornblendeschist of cambro-silurian age. Glacial striae are found at several places. A strand-line, which has been descrived several times occurs along the mountain side to the West of the town. A picture of part of it is shown on p.117. The small mountain Sverresborgklimpen is designated with one and its neighbour with two flying birds in the back ground. On the next two pages one sees a section and drawings of these mountains. They are interesting by their forms and the ledges along their sides both due to marine erosion. The whole region has been submerged up to a height of nearly 200 m. During this time gravel and sand were deposited along the coasts and clay in the deep water.