Stratigraphy and environmental reconstruction at the middle Wisconsinan Gilman Canyon Formation type locality, Buzzard's Roost, southwestern Nebraska, USA

TitleStratigraphy and environmental reconstruction at the middle Wisconsinan Gilman Canyon Formation type locality, Buzzard's Roost, southwestern Nebraska, USA
Publication TypeJournal Article
Year of Publication2007
AuthorsJohnson, WC, Willey, KL, Mason, JA, May, DW
JournalQuaternary Research
Volume67
Issue3
Pagination474-486
Date PublishedMay
ISSN0033-5894
Accession NumberWOS:000245960800017
Abstract

The middle Wisconsinan Gilman Canyon Formation at the Buzzard's Roost type locality in southwestern Nebraska was investigated to document the stratigraphy and to reconstruct the environmental and climate record. The Gilman Canyon Formation was subdivided into three loess units and three soils, with radiocarbon ages constraining it between about 40 ka and 25 ka. Stable carbon isotope ratios, magnetic susceptibility, and carbon content were used to define and characterize soils within both the Gilman Canyon Formation and underlying Illinoian Loveland Loess. At the height of soil development within the Gilman Canyon Formation, climate was supporting C-4-dominated grassland, with July temperatures equal to or exceeding those of today. Soil-forming intervals within the Loveland Loess, including the Sangamon Soil, also exhibited relative increases in C-4 biomass. Climate, as recorded in the Gilman Canyon Formation, is corroborated by regional proxy data. The formation accumulated during MIS 3, and concurrent soil formation coincided with a summer insolation maximum. (c) 2007 University of Washington. All rights reserved.

DOI10.1016/j.yqres.2007.01.011