Properties

The main physical properties for this case history is electrical resistivity. Expected resistivity values for the different sediments in the Kasted region are displayed in the table below. The determination of the resistivity values in the table are based on direct comparison of borehole data with measured resistivities from TEM-surveys, but also with resistivity log data. Measurements of resistivity values for different sediment types have also been conducted directly on borehole samples.

The buried valleys are shaped like a bowl, where the bottom is constituted by Paleogene clay and the infill (where water is typically found) is constituted by sand and gravel. This makes the geological setting an ideal target for ATDEM since there is strong resistivity contrast between the geological units.

Geological Units	Resistivity (\(\Omega m\))
Palaeogene Clay	1-10
Clay Till	25-60
Sand Till	>50
Meltwater Sand and Gravel	>60
Glaciolacustrine Clay	10-40
Miocene Silt and Sand	>40
Miocene Clay	10-40
Sand	>40
Clay	1-60