Faculty Publications

Stratigraphy And Environmental Reconstruction At The Middle Wisconsinan Gilman Canyon Formation Type Locality, Buzzard's Roost, Southwestern Nebraska, USA

Document Type

Article

Keywords

Buzzards Roost, Gilman Canyon Formation, Loess, Loveland Loess, Magnetic susceptibility, Middle Wisconsinan, MIS 3, Nebraska, Paleoclimate, Stable isotopes

Journal/Book/Conference Title

Quaternary Research

Volume

67

Issue

3

First Page

474

Last Page

486

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 C4-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 C4 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. © 2007 University of Washington.

Department

Department of Geography

Original Publication Date

5-1-2007

DOI of published version

10.1016/j.yqres.2007.01.011

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