Ad
related to: quaternary glaciations extent and chronology of data collection and research
Search results
Results From The WOW.Com Content Network
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.
Detailed research by various geomorphologists and Quaternary geologists demonstrated that the two glacial tills and one ash bed stratigraphic model, on which the Yarmouthian, Kansan, Nebraskan, and Aftonian glacial - interglacial nomenclature was based, was completely wrong.
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 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 .
The Bull Lake glaciation began about 200,000 years ago and ended about 130,000 years ago, and was concurrent with the Illinoian Stage of the Quaternary Ice Age. [1] There is disagreement over these time frames, however, and further research is necessary. [2] This glacial period was identified by geologist Eliot Blackwelder. [3]
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.
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.