Iowan Drift Problem, Northeastern Iowa: Report of Investigations 7, 1968

(1968) Iowan Drift Problem, Northeastern Iowa: Report of Investigations 7, 1968. University of Iowa

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Abstract

For the past two decades existence of the lowan drift has not been questioned, but an argument has arisen as to its placement in the Wisconsin stage. After formalizing the Farmdale, Leighton and Willman (1950) placed the lowan as the next younger Wisconsin substage. However, all radiocarbon dates of wood extracted from the drift, that was identified by previous workers as lowan, were "greater than" values, whereas the Farmdale is dated at 22,000-26,000 years. Accordingly, Ruhe and associates (1957, 1959) proposed and reaffirmed that the lowan was older than Farmdale, but Leighton (1958, 1960, 1966) objected to this alignment.

Item Type: Departmental Report
Keywords: Geology, Mines, Geological Survey, Iowa
Subjects: Natural resources and environment
Natural resources and environment > Earth sciences
Natural resources and environment > Energy resources > Coal
Natural resources and environment > Environmental assessments
ID Code: 25824
Deposited By: Margaret Barr
Deposited On: 05 Dec 2017 19:53
Last Modified: 05 Dec 2017 19:53
URI: http://publications.iowa.gov/id/eprint/25824