Search results
Results from the WOW.Com Content Network
The Quaternary (/ k w ə ˈ t ɜːr n ə r i, ˈ k w ɒ t ər n ɛr i / kwə-TUR-nə-ree, KWOT-ər-nerr-ee) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the Phanerozoic eon. [3]
The Cenozoic is divided into three periods: the Paleogene, Neogene, and Quaternary; and seven epochs: the Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, and Holocene. The Quaternary Period was officially recognised by the International Commission on Stratigraphy in June 2009. [9]
Long before the Quaternary glaciation, land-based ice appeared and then disappeared during at least four other ice ages. The Quaternary glaciation can be considered a part of a Late Cenozoic Ice Age that began 33.9 Ma and is ongoing.
The Late Cenozoic Ice Age began 34 million years ago, its latest phase being the Quaternary glaciation, in progress since 2.58 million years ago. Within ice ages, there exist periods of more severe glacial conditions and more temperate conditions, referred to as glacial periods and interglacial periods, respectively.
The glaciation and the current Quaternary Period both began with the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Mya, in the mid-Cenozoic (Eocene–Oligocene extinction event), and the term Late Cenozoic Ice Age is used to include this early phase with the current glaciation. [3]
The Late Cenozoic Ice Age falls within the Cenozoic Era which started 66 million years ago. The Cenozoic Era is part of the Phanerozoic Eon which started ~538.8 million years ago. ^ a b In standard nomenclature the Pleistocene Epoch lasts from 2.58 Ma to 11.7 ka and the Holocene epoch lasts from 11.7 ka to present.
The Quaternary Period, the Cenozoic Era geologic time unit from the end of the Pliocene Epoch, roughly 1.8−1.6 million years ago, to the present day. The Quaternary has 2 geologic/geochronologic subdivisions, the Pleistocene and the Holocene Epochs
The Quaternary spans from 2.58 million years ago to present day, and is the shortest geological period in the Phanerozoic Eon. It features modern animals, and dramatic changes in the climate. It is divided into two epochs: the Pleistocene and the Holocene. The Pleistocene lasted from 2.58 million to 11,700 years ago.