The term is used to denote the usual strata of a region in relation to the rock which is being discussed or observed.
The following are areas in geology when the term country rock is used;
- Intrusive settings; when describing a pluton or dike one may describe the igneous rock as intruding the surrounding country rock, the rock into which the pluton has intruded.
- In describing the texture or structure of lit-par-lit intrusion, the intrusive is described in relation to the country rock or wall rock
- Alluvial settings; when describing recent alluvium the material that has arrived through volcanic, glacial or fluvial action can be described as a veneer on the country rock