Page "Relict" Paragraph 17

Some geologic processes are destructive or transformative of structures or minerals, and when a process is not complete or does not completely destroy certain features, the left-over feature is a relict of what was there before.

For example, relict permafrost is an area of ancient permafrost which remains despite a change in climate which would prohibit new permafrost from forming.

Or it could be a fragment of ancient soil or sediment found in a younger stratum.

A relict sediment is an area of ancient sediment which remains unburied despite changes in the surrounding environment.

In pedology, the study of soil formation and classification, ancient soil found in the geologic record is called a paleosol, material formed in the distant past on what was then the surface.

A relict paleosol is still found on the surface, and yet is known to have been formed under conditions radically different from the present climate and topography.