Pleistocene(redirected from 12th millennium BCE)
Also found in: Dictionary, Thesaurus, Wikipedia.
the first division, corresponding to the longest epoch, of the Anthropogenic (Quaternary) period. The Pleistocene is characterized by a general cooling of the earth’s climate and periodic occurrence of extensive continental glaciation in the middle latitudes. Some researchers, including the Soviet geologist V. I. Gromov, classify the beginning of the Pleistocene as a separate epoch preceding the Pleistocene proper. This separate epoch, called the Eopleistocene, includes the Upper (Late) Pliocene, which is classified by most researchers in the Neogene.
The term “Pleistocene” was proposed in 1832 by the British geologist C. Lyell for the marine deposits immediately preceding deposits of the modern period because of the predominance of presently existing forms of fauna in these deposits.