The Salt Axis – Gronau-Epe

The Salt in Westmünsterland

The salt found here is part of the Lower Rhine salt flat and extends from the Rhine through Emsland and into the Netherlands. The salt formed over 200 million years ago with the evaporation of a primeval sea and was deposited at a depth of roughly 1,000 to 1,400 meters. It is a very pure (98-99%) form of cooking salt. Since 1972, the salt has been extracted with water. This brine is a very important raw material for the chemical industry. In addition, salt is a dense host rock for caverns in which petroleum and natural gas are stored.

The salt was discovered in the search for oil and natural gas and then excavated by drilling. Good maps showing the size of the salt flat emerged with the development of seismic measurement methods. For seismic measurements, waves are produced with hammer blows, explosives, or vibratory machines at profile points. Geophones lined up in a grid-formation record the waves reflected up from the underground layers. An evaluation of the wave travel times can produce an accurate picture of the deep rock layers.

Georg Hengst, Salzgewinnungsgesellschaft Westfalen, Ahaus