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:
“For the child whose impulsiveness is indulged, who retains his primitive-discharge mechanisms, is not only an ill-behaved child but a child whose intellectual development is slowed down. No matter how well he is endowed intellectually, if direct action and immediate gratification are the guiding principles of his behavior, there will be less incentive to develop the higher mental processes, to reason, to employ the imagination creatively. . . .”
—Selma H. Fraiberg (20th century)
“The experience of a sense of guilt for wrong-doing is necessary for the development of self-control. The guilt feelings will later serve as a warning signal which the child can produce himself when an impulse to repeat the naughty act comes over him. When the child can produce his on warning signals, independent of the actual presence of the adult, he is on the way to developing a conscience.”
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“As a final instance of the force of limitations in the development of concentration, I must mention that beautiful creature, Helen Keller, whom I have known for these many years. I am filled with wonder of her knowledge, acquired because shut out from all distraction. If I could have been deaf, dumb, and blind I also might have arrived at something.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)