Structuur van de ijskap op de oostelijke Veluwe

Eskers, being the former beds of glacial streams during the melting period of the passive ice mass, may indicate in place and direction the systems of crevasses in the ice cap. In this way at least two systems of crevasses may be recognized on the eastern push moraine of the Veluwe (central part of the Netherlands). One about E — W, crossing the moraine wall and one parallel to its longest axis. The latter system curves from NNE—S SW in the north to NNW—S SE in the south, obviously following the curve of the push moraine. By a local progression of the ice mass from E to W against and across the wall, the E —W oriented parts of the eskers represent tension joints, which are due to the lateral extension of the ice sheet when reaching the top of the wall. At the same time the wall buckled the overflowing ice sheet, which caused tension joints parallel to the push moraine. In the passive state of the ice mass both systems of crevasses were used by glacial streams, thus building up parts of the eskers in both directions (Fig. 24).