Page:The Journal of geology (IA journalofgeology21894univers).pdf/141

outwards in it, following the line of least resistance for the ice overflow in central Scandinavia. This only need be 1,500 meters thick to be able to erode the bottom when the maximum erosion was in progress. This ice stream turned round the Naze and left its bottom moraine also on the southwestern Norwegian coastland, e.g., on Jaederen, where boulders from the Kristiania territory are very numerous.

While the extreme eastern margin of the first great inland ice, as demonstrated by the extension of the boulder clay, reached to Kiew and Petschora, we must thus place the western margin at the steep slope to the Norway deep in the North Atlantic Ocean. But we have reason to think that it did not remain there for a very long time. As the weight of the ice increased the land was obliged to sink below it. This follows not only from the general physics of the earth's crust as demonstrated by O. Fisher, but can also be directly deduced from facts observed in all former glaciated countries. Invariably when there comes an inland ice there follows a depression; with the melting of it there is everywhere a re-upheaval; and everywhere the amplitude of the crust motion is in close accord with the thickness of the ice sheet.^[1] Under the great first inland ice, Norway sank and therewith came a raising of the snow line in relation to the ice surface and an aggression on the ice from the rising sea. Under these circumstances the ice margin was forced back, and many things indicate that it at length took up its position at about the present coast line and paused there while the great terminal glaciers flowed down preglacial depressions and made new ones and scooped out, by long continued action, our grand fjords. Judging from their form and great dimensions, this erosion took place under very constant circumstances. The ice must have kept its place for a very long period constituting, in all probability, the greater part of the first great ice age. It might be objected that when the ice receded by the sinking of the land, the crust upheaval must have followed immediately. As the sea with its