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Such evidence suggests major periods of glaciation prior to the current Quaternary glaciation. One of the best documented records of pre-Quaternary glaciation, called the Karoo Ice Age, is found in the late Paleozoic rocks in South Africa, India, South America, Antarctica, and Australia. Exposures of ancient glacial deposits are numerous in ...
The marine record preserves all the past glaciations; the land-based evidence is less complete because successive glaciations may wipe out evidence of their predecessors. Ice cores from continental ice accumulations also provide a complete record, but do not go as far back in time as marine data.
The only issue with interpreting the data from this region is due to the lack of chronological information. [13] The resemblance of Late Pleistocene species in Northern Africa to modern animals is the same as in Southern Africa but it's extremely difficult to date when these fauna came into place because of the lack of reliable samples from the ...
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]
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 stage names "Kansan", "Yarmouth", "Nebraskan" and "Aftonian" were later abandoned by North American Quaternary geologists and merged into the Pre-Illinoian stage. [ 9 ] [ 10 ] The Anglian Stage is now correlated with the period of time which includes the Pre-Illinoian B glaciation of North America.
The Illinoian Stage is the name used by Quaternary geologists in North America to designate the Penultimate Glacial Period c.191,000 to c.130,000 years ago, during the late Middle Pleistocene (Chibanian), when sediments comprising the Illinoian Glacial Lobe were deposited.
Kansan glaciation was used by early geomorphologists and Quaternary geologists to subdivide glacial and nonglacial deposits within north-central United States from youngest to oldest and are as follows: Wisconsin (glacial) Sangamonian (interglacial) Illinoian (glacial) Yarmouthian (interglacial) Kansan (glacial) Aftonian (interglacial ...