II. Om isskillet i trakten omkring Fæmund

Abstract

Forkortet: As Hørbye first pointed out, the erratic blocks in the region around Femunden show that the ice of E of a line from Sorkvola to Tufsingdal has moved north- wards, while the movement W of that line has been southward. From this the author previously concluded that the iceshed in Norway cannot have formed a direct continuation of that in Sweden. The direction of the latter has been towards the SW, and has ended a little S of Femunden, whereas the iceshed in Norway must have begun a little to the N of Femunden up about Hummelfjell, and thence moved towards the SW. In order to explain the transportation of blocks in the region under discussion, the author starts with the assumption that the ice in the neighbourhood of the iceshed sinks vertically, and only when near the bottom moves out to both sides along the underlying ground. If, for the sake of simplicity, we assume the surface of the ground to be flat and horizontal, the movement of the ice will on the whole resemble that of a fluid flowing along the ground to both sides from the projection of the iceshed on the base. If this projection be a limited right line, the stream-lines will be confocal hyperbolae, with the right line as the real axis, and its extremities as foci. If there are two separate icesheds, the movement of the interjacent masses of ice along the bottom will be the resultant of two such motions, each issuing from its iceshed.