Quaternary aminostratigraphy of Mississippi Valley loess

Research Article| July 01, 1989 Quaternary aminostratigraphy of Mississippi Valley loess PETER U. CLARK; PETER U. CLARK 1Department of Geological Sciences, University Illinois, Chicago, Illinois 60680 Search for other works by this author on: GSW Google Scholar ALAN R. NELSON; ALAN R. NELSON 2Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado 80309-04503U.S. Geological Survey, M.S. 966, P.O. Box 25046, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar WILLIAM D. McCOY; WILLIAM D. McCOY 4Department of Geology and Geography, University of Massachusetts, Amherst Massachusetts 01003 Search for other works by this author on: GSW Google Scholar BARRY B. MILLER; BARRY B. MILLER 5Department of Geology, Kent State University, Kent, Ohio 44242 Search for other works by this author on: GSW Google Scholar DIANE K. BARNES DIANE K. BARNES 1Department of Geological Sciences, University Illinois, Chicago, Illinois 60680 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1989) 101 (7): 918–926. https://doi.org/10.1130/0016-7606(1989)101<0918:QAOMVL>2.3.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation PETER U. CLARK, ALAN R. NELSON, WILLIAM D. McCOY, BARRY B. MILLER, DIANE K. BARNES; Quaternary aminostratigraphy of Mississippi Valley loess. GSA Bulletin 1989;; 101 (7): 918–926. doi: https://doi.org/10.1130/0016-7606(1989)101<0918:QAOMVL>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Five Pleistocene loess units in the Mississippi Valley that contain terrestrial gastropod fossils are differentiated by amino acid ratios (aIle/Ile values) in the total acid hydrolysate of the fossil terrestrial gastropods Hendersonia occulta, Catinella and Succinea. Late Wisconsin Peoria Loess, which has been independently dated by radiocarbon and thermoluminescence methods, is identified by alle/Ile values in fossil gastropods which progressively increase from northern Illinois to southern Louisiana. Early(?) to middle Wisconsin Roxana Silt is characterized by alle/Ile values in Hendersonia only slightly greater, and values in Catinella and Succinea distinctly greater than those of the Peoria Loess. AIIe/Ile values in Hendersonia suggest that the "Chinatown silt" (informal term) in Illinois and the Loveland Silt in Arkansas are the same age. Independent geologic evidence suggests that they predate the Sangamon (last interglacial). AIle/Ile values in Hendersonia from the "Sicily Island loess" (informal term) in Louisiana indicate that it is significantly older than the Loveland Silt and the "Chinatown silt". The oldest loess unit recognized by alle/Ile values in Hendersonia from the Mississippi Valley is the "County Line silt" (informal term) in Illinois. The study shows that amino acid ratios in fossil gastropods from loess are an extremely valuable relative-age indicator and provide a means of long-distance correlation of midcontinent loess deposits. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.