Description

A specific case of plastic and plastic/brittle deformation of strata in which valley downcutting and the associated removal of the overburden stress results in passive failure of formerly competent rocks and their subsequent upward deformation. This results in weaker rocks below the valley floor becoming stressed laterally and being forced upwards, becoming folded and faulted. The greatest deformation is usually concentrated on the alignment of the valley's lowest point.

Usually attributed to stress relief under periglacial conditions, caused by erosion of material along valley floors and frost-induced heave.

Category

Category of FEP

Geosynthesis

Sub-category

Sub-category of FEP

Internal geodynamic events - plastic deformation of host rock

Ondraf Niras FEP Number

Ondraf Niras FEP Number

37

FEP Effects

Description of FEP Effects

Plastic deformation may change shape of host rock layer and its physical properties such as density, preferred orientation of host rock minerals and porosity.

Reference(s)

References Relevant to FEP

ER-184_I2 RD&D Plan

NEA TN2 IFEP Reference(s)

Related IFEPs from the NEA TN2 List of Proposed IFEP Revisions [NEA/RWM/R(2013)8]

1.2.3 Deformation (elastic, plastic or brittle).