geological_period (HyperDic hyper-dictionary)

English > 1 sense of the expression *geological period*:
NOUN	time	geological period, period	a unit of geological time during which a system of rocks formed

English > *geological period*: 1 sense > noun 1, time
Meaning	A unit of geological time during which a system of rocks formed.
Example	"ganoid fishes swarmed during the earlier geological periods"
Synonym	period
Instances	Cambrian, Cambrian period	From 544 million to about 500 million years ago
	Carboniferous, Carboniferous period	From 345 million to 280 million years ago
	Cretaceous, Cretaceous period	From 135 million to 63 million years ago
	Devonian, Devonian period, Age of Fishes	From 405 million to 345 million years ago
	Jurassic, Jurassic period	From 190 million to 135 million years ago
	Mississippian, Missippian period, Lower Carboniferous, Lower Carboniferous period	From 345 million to 310 million years ago
	Ordovician, Ordovician period	From 500 million to 425 million years ago
	Pennsylvanian, Pennsylvanian period, Upper Carboniferous, Upper Carboniferous period	From 310 million to 280 million years ago
	Permian, Permian period	From 280 million to 230 million years ago
	Quaternary, Quaternary period, Age of Man	last 2 million years
	Silurian, Silurian period	From 425 million to 405 million years ago
	Tertiary, Tertiary period	From 63 million to 2 million years ago
	Triassic, Triassic period	From 230 million to 190 million years ago
Part of	era, geological era	A major division of geological time
Parts	epoch	A unit of geological time that is a subdivision of a period and is itself divided into ages
Narrower	ice age, glacial period, glacial epoch	Any period of time during which glaciers covered a large part of the earth's surface
Broader	geological time, geologic time	The time of the physical formation and development of the earth (especially prior to human history)
Spanish	periodo, período
Catalan	període

HyperDic: geological_period