/ep"euhk/ or, esp. Brit., /ee"pok/, n.1. a particular period of time marked by distinctive features, events, etc.: The treaty ushered in an epoch of peace and good will.2. the beginning of a distinctive period in the history of anything: The splitting of the atom marked an epoch in scientific discovery.3. a point of time distinguished by a particular event or state of affairs; a memorable date: His coming of age was an epoch in his life.4. Geol. any of several divisions of a geologic period during which a geologic series is formed. Cf. age (def. 12). See table under geologic time.5. Astron.a. an arbitrarily fixed instant of time or date, usually the beginning of a century or half century, used as a reference in giving the elements of a planetary orbit or the like.b. the mean longitude of a planet as seen from the sun at such an instant or date.6. Physics. the displacement from zero at zero time of a body undergoing simple harmonic motion.[1605-15; < NL epocha < Gk epoché pause, check, fixed time, equiv. to ep- EP- + och- (var. s. of échein to have) + -e n. suffix]
* * *IUnit of geologic time during which a rock series is deposited.It is a subdivision of a geologic period. Additional distinctions can be made by adding relative time terms, such as early, middle, and late. The use of the term is usually restricted to divisions of the Tertiary and Quaternary periods.II(as used in expressions)Recent EpochPalaeocene Epoch
* * *unit of geological time during which a rock series is deposited. It is a subdivision of a geological period and the word is capitalized when employed in a formal sense (e.g., Pleistocene Epoch). Additional distinctions can be made by appending relative time terms, such as early, middle, and late. The use of “epoch” is usually restricted to divisions of the Tertiary and Quaternary periods.
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