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The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial and interglacial periods during the Quaternary period that began 2.58 Ma (million years ago) and is ongoing.
A minor series of glaciations occurred from 460 to 430 Ma, and there were extensive glaciations from 350 to 289 Ma. The Late Cenozoic Ice Age has seen extensive ice sheets in Antarctica for the last 34 Ma. During the last 3 Ma, ice sheets have also developed on the northern hemisphere.
The timeline of glaciation covers ice ages specifically, which tend to have their own names for phases, often with different names used for different parts of the world. The names for earlier periods and events come from geology and paleontology. The marine isotope stages (MIS) are often used to express dating within the Quaternary.
The Quaternary Period follows the Neogene Period and extends to the present. The Quaternary covers the time span of glaciations classified as the Pleistocene, and includes the present interglacial time-period, the Holocene. This places the start of the Quaternary at the onset of Northern Hemisphere glaciation approximately 2.6 million years ago .
For example, instead of two glaciations having occurred prior to the Illinoian Stage, researchers found that 11 distinct glaciations had occurred. In addition, what was presumed to have been a single volcanic ash bed, which was used to correlate and differentiate between Kansan and Nebraskan glacial deposits, was found to be three volcanic ash ...
The Laurentide ice sheet (LIS) was a massive sheet of ice that covered millions of square miles, including most of Canada and a large portion of the Northern United States, multiple times during the Quaternary glaciation epochs, from 2.58 million years ago to the present. [2]
Four of the glaciations (MIS 22, MIS 20, MIS 18, MIS 14) were moderate, probably involving low-land glaciation in Scandinavia, but not spreading to England and northern Germany. [1] One of the glaciations, Marine Isotope Stage 16 (MIS 16), is globally as strong as the most recent glaciations, MIS 6 (main Saale ) and MIS 2 ( Weichsel/Devensian ).
The Mid-Pleistocene Transition (MPT), also known as the Mid-Pleistocene Revolution (MPR), [1] is a fundamental change in the behaviour of glacial cycles during the Quaternary glaciations. [2] [3] The transition lasted around 550,000 years, [4] from 1.25 million years ago until 0.7 million years ago approximately, in the Pleistocene epoch. [5]