(1968) Iowan Drift Problem, Northeastern Iowa: Report of Investigations 7, 1968. University of Iowa
|
PDF
2014-10-27_19-10-46_ri-7.pdf File Size:2MB |
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: | https://publications.iowa.gov/id/eprint/25824 |