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Pleistocene epoch
(Encyclopedia)Pleistocene epoch plīˈstəsēn [key], 6th epoch of the Cenozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table). According to a classification that considered its depos...epoch
(Encyclopedia)epoch, unit of geologic time that is a subdivision of a period. The Pleistocene and Holocene epochs, for example, are divisions of the Quaternary period. Epoch is also used to describe a short length ...Holocene epoch
(Encyclopedia)Holocene epoch hŏlˈəsēn [key] or Recent epoch, most recent of all subdivisions of geologic time, ranging from the present back to the time (c.11,000 years ago) of almost complete withdrawal of the...Pliocene epoch
(Encyclopedia)Pliocene epoch plīˈəsēn [key], fifth epoch of the Cenozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table), from 5.1 to 2 million years ago. By the beginning of the P...mastodon
(Encyclopedia)mastodon măsˈtədŏnˌ [key], name for a number of prehistoric mammals of the extinct genus Mammut, from which modern elephants are believed to have developed. The earliest known forms lived in the ...Ice Age
(Encyclopedia)Ice Age: see Pleistocene epoch.Lahontan, Lake
(Encyclopedia)Lahontan, Lake ləhŏnˈtən [key], extinct lake of W Nev. and NE Calif. It was formed by heavy precipitation caused by the Pleistocene glaciers and with Lake Bonneville (see under Bonneville Salt Fla...Eocene epoch
(Encyclopedia)Eocene epoch ēˈəsēnˌ [key], second epoch of the Tertiary period in the Cenozoic era of geologic time, from approximately 54.9 to 38 million years ago. The Eocene in North America was marked by th...Miocene epoch
(Encyclopedia)Miocene epoch mīˈəsēn [key], fourth epoch of the Tertiary period in the Cenozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table), lasting from around 24.6 to 5.1 mill...Oligocene epoch
(Encyclopedia)Oligocene epoch ŏlˈəgōsēnˌ [key], third epoch of the Tertiary period in the Cenozoic era of geologic time, lasting from 38 to 24 million years ago. More of North America was dry land during the ...Browse by Subject
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