Development
This climatic and chronological framework was composed of four glacial and interglacial stages. It was developed between 1894 and 1909 by geomorphologists and Quaternary geologists to subdivide glacial and nonglacial deposits within the United States of America. From youngest to oldest, they were the Wisconsin glaciation, Sangamonian (interglacial), Illinoian Stage (glacial), Yarmouthian, Kansan glaciation, Aftonian (interglacial), and Nebraskan stages. The Yarmouthian (Yarmouth) Interglacial was defined first on the basis of "interglacial" sediments encountered in wells dug in southeasterm Iowa. Later the Yarmouth (Yarmouthian) stage in Illinois was defined on the basis of the Yarmouth Paleosol (Soil) developed in the surface of what were thought at that time to be "Kansan" glacial tills and buried by Illionian glacial tills of the Glasford Formation in southeast Iowa and east-central Illinois. At this time, it was incorrectly presumed that the Yarmouth Paleosol formed during a single interglacial stage that separated a younger glacial stage, the Illinoian Glaciation, represented by the sediments of the Glasford Formation in Illinois and the glacial deposits of an older glacial stage, called the "Kansan Glaciation".
Read more about this topic: Yarmouthian (stage)
Famous quotes containing the word development:
“I could not undertake to form a nucleus of an institution for the development of infant minds, where none already existed. It would be too cruel.”
—Henry David Thoreau (1817–1862)
“The development of civilization and industry in general has always shown itself so active in the destruction of forests that everything that has been done for their conservation and production is completely insignificant in comparison.”
—Karl Marx (1818–1883)
“Information about child development enhances parents’ capacity to respond appropriately to their children. Informed parents are better equipped to problem-solve, more confident of their decisions, and more likely to respond sensitively to their children’s developmental needs.”
—L. P. Wandersman (20th century)