44 D18. Geomorphology (Posters)

Tuesday, 22 March 2022
8:00 AM - 12:00 PM
Freedom Hall A

PALEOCHANNELS IN THE KUTZTOWN UNIVERSITY RONALD R. RHEIN ENVIRONMENTAL STUDY AREA

Paper number: 44-1
Program: Technical Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

The most recent glaciation event in the mid-Pleistocene caused global sea level and regional base level to drop. This allowed rivers and-streams in the Northeastern United States to incise bedrock. During this study, core samples were taken and several lines of GPR data were run near the current stream channel on the Kutztown University Ronald R. Rhein Environmental Study Area to determine if previous paleochannels incised the bedrock. We investigated three separate locations along the stream channel using GPR, and fifteen hand cores were dug in locations believed to hold paleochannel deposits. Using the subsurface data from both the GPR and core samples, paleochannels were located on both sides of the active stream channel. None of the paleochannels appear to have incised bedrock, however, several incised to the bedrock/sediment interface. Lack of incision is possibly due to inadequate time for the pulse of incision to migrate through the Schuylkill River watershed to this stream before the glaciers melted. The estimated path of the paleochannel suggests that the stream is becoming more meandering over time. The sinuosity of the current channel was calculated to be 1.28, and the sinuosity of the estimated paleochannel was found to be 1.20. The GPR data suggests that the paleo stream depth was similar to the current stream, and the sediment size from the core samples imply the energy was similar to the current stream. These data suggest that this stream system is largely stable over time. However, the increase in sinuosity could indicate a change in local landscape relief associated with post-colonial land clearing and hillslope erosion.

Geological Society of America Abstracts with Programs. Vol. 54, No. 3

doi: 10.1130/abs/2022NE-375221

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