E

Glossary of geological terms

ABCDEFGHI J KL
MN OP QRSTU VW X Y Z

eon / aeon

The largest subdivision of geological time.  The last 542 million years comprise the Phanerozoic Eon. See geological timescale.

epoch / epoc

A subdivision of geological time smaller than a period and larger than a stage.  The rocks formed within an epoch constitute a series. See geological timescale.

era / gorgyfnod

A subdivision of geological time smaller than an eon and larger than a period.  See geological timescale.

Euramerica / Ewramerica

See ‘Old Red Sandstone Continent’.