Answer:

epoch

Answer	Crossword Clue
EPOCH	Memorable period
EPOCH	Geologic time
EPOCH	Distinctive period

EPOCH	Geological period
EPOCH	Long time
EPOCH	Geologist's division
EPOCH	Paleontology period
EPOCH	Holocene, for one
EPOCH	Noteworthy period
EPOCH	Notable time span
EPOCH	Pliocene, e.g.

EPOCH	Historical period
EPOCH	Historical time
EPOCH	Era
EPOCH	Geological time
EPOCH	The Eocene, for one
EPOCH	Extended period
EPOCH	Period of note
EPOCH	Pleistocene, e.g.

EPOCH	Historic period
EPOCH	Significant period
EPOCH	Prominent period
EPOCH	Distinctive historical period
EPOCH	Period of history
EPOCH	Period on a geologic time scale
EPOCH	Long period of time
EPOCH	Memorable time

EPOCH	Beginning of a historic period
EPOCH	Geological span
EPOCH	Period piece
EPOCH	Geologic time unit
EPOCH	Time to remember
EPOCH	Period in history
EPOCH	Notable time period
EPOCH	Geologic period

EPOCH	Period piece?
EPOCH	Notable period
EPOCH	Special period
EPOCH	Memorable period of time
EPOCH	Remarkable time