NAGRA Opalinus Clay (…002 - Version 1
FEP 16.1.3 Compaction of Opalinus Clay

There are indications that the porewater in the Opalinus Clay is overpressured, even though the overlying sediments are currently being eroded. This possibly reflects an earlier period of rapid loading, during which concomitant drainage and compaction of the Opalinus Clay was only partially achieved. As a result of future glaciations, an episodic increase of the total load on the Opalinus Clay is expected. Overpressures can be dissipated either by porewater drainage and compaction of the clay or by reduction of the total load imposed (erosion of overburden).