Of a stratum (esp. a fossiliferous deposit), glacier, or other structure: consisting of or containing material from an older formation that has…

Physical Geography. Of a stream, valley, etc.: having a direction or character determined by the resistance to erosion of the underlying rock, and…

Almost contemporaneous; esp. (of a process) occurring immediately after deposition of a particular stratum.

Geology. Applied to mineral deposits formed at the same time as the enclosing rocks; characterized by or pertaining to a formation contemporaneous…

Geology. Originating within the earth (or another planet) and brought to the surface for the first time.

Geology. Of a rock structure: partially preserving the texture that existed prior to metamorphism.

Geology. Exhibiting or characteristic of diachronism (see diachronism, n. 1); not of a uniform geological age.

of or relating to tectonic features or events of previous stages in the earth's history.