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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]
Ancient history – Aggregate of past events from the beginning of recorded human history and extending as far as the Early Middle Ages or the Postclassical Era. The span of recorded history is roughly five thousand years, beginning with the earliest linguistic records in the third millennium BC in Mesopotamia and Egypt .
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 .
There have been five or six major ice ages in the history of Earth over the past 3 billion years. 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.
Each Quaternary climate phase has been assigned with a marine isotope stage (MIS) number, which describes the alternation between warmer and cooler temperatures, as measured by oxygen isotope data. Stadials have even MIS numbers, and interstadials have odd MIS numbers.
Quaternary science is the subfield of geology which studies the Quaternary Period commonly known as the ice age. The Quaternary Period is a time period that started around 2.58 million years ago and continues today. [1] [2] This period is divided into two epochs – the Pleistocene Epoch and the Holocene Epoch.
The Quaternary glaciation produced more lakes than all other geologic processes combined. The reason is that a continental glacier completely disrupts the preglacial drainage system . The surface over which the glacier moved was scoured and eroded by the ice, leaving many closed, undrained depressions in the bedrock.
The Quaternary is a geologic period. Quaternary (an adjective meaning "fourth in order" or "composed of four items") may also refer to: Quaternary (chemistry) (see also Quaternary compound and Quaternary phase) Quaternary structure of proteins; Quaternary sector of the economy, which encompasses knowledge-based services