T66 Sigma Gamma Epsilon Student Research (Posters)

Monday, 28 October 2002
8:00 AM - 12:00 PM

STRATIGRAPHIC CORRELATION OF PALEOSOLS TO REFINE THE CLASSIFICATIONS OF SOD TABLES, BADLANDS NATIONAL PARK, SOUTH DAKOTA

Paper number: T66-9
Program: Technical Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

Seagriff et al. (2001) suggested that difficulties in categorizing geomorphic sequences of sod tables in the White River Badlands could be surmounted by stratigraphic techniques, including magnetic susceptibility and radiocarbon dating of paleosols in Quaternary colluvial-alluvial deposits. We undertook these tasks with field work in May 2002 and subsequent lab analyses. Magnetic susceptibility is being used for identification of distinctive paleosols for radiocarbon dating. These paleosols can then be used as marker beds for correlation among sod tables. Ultimately, classification of sod tables is envisioned to be useful for paleoclimatic reconstruction for the region, as they represent a vestige of transitions between episodes of net aggradation vs. degradation of fans.

Our research team consists of seven undergraduates and two professors from Slippery Rock University. We described and sampled nine sod tables from three localities in the park. Along the Old North East Road, five soil profiles were described, within which three horizons were identified as potential correlating paleosols. Two of the correlating paleosols were found in two separate profiles. Profile depths ranged from 45 to 122 cm. South of Saddle Pass, three exposures were profiled, revealing three potential paleosols. One of the potential paleosols is exposed along all three profiles, while another is present in two profiles. Profile depths ranged from 131 to 297 cm. Along the Loop Road entrance from Cactus Flats, one 141 cm profile contained no paleosols.

We are seeing a relationship between magnetic susceptibility signatures that are consistent with the presence of paleosols. These results will guide the selection of samples for radiocarbon dating. Absolute dating of paleosols will then begin to constrain the timing of fan development and enhance the ability to classify and correlate the many generations of sod tables visible within the park.