Structure of a Pleistocene push moraine revealed by GPR: the eastern Veluwe Ridge, The Netherlands

Abstract

AbstractThe classic idea on the architecture of the push moraines of The Netherlands is one of imbricated thrusts. This study shows a more complete model of the structural style within a push moraine. We have mapped three glaciotectonic styles using 50 MHz ground penetrating radar (GPR).The moraines are composed of coarse-grained unconsolidated sediments of fluvial and glaciofluvial origin. Maximum penetration depth is about 45 m. In a 12 km cross-section over the eastern Veluwe Ridge we have encountered the following glaciotectonic styles. Style I is found near the former ice margin and consists of imbricated thrust sheets, with thrust planes dipping towards the former glacier. Style II, further away from the glacier, is a combination of folds and thrust structures. The folds have a wavelength of up to 200 m and an amplitude of 40 m. Style III is almost entirely composed of large-scale folds with wavelengths of 400 m maximum. Toward the most distal parts of the ridges the folds flatten out.The study shows that GPR is capable of imaging large-scale glaciotectonic structures, resulting in a factual model of the eastern Veluwe push-moraine architecture and better insight into postglacial denudation amounts and push-moraine genesis.