The role of lithology and climate on bedrock river incision and terrace development along the Buffalo National River, Arkansas
Quaternary Research
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Abstract
The Buffalo National River in northwest Arkansas preserves an extensive Quaternary record of fluvial bedrock incision and aggradation across lithologies of variable resistance. In this work, we apply optically stimulated luminescence (OSL) dating to strath and fill terraces along the Buffalo River to elucidate the role of lithology and climate on the development of the two youngest terrace units (Qtm and Qty). Our OSL ages suggest a minimum strath planation age of ~250 ka for the Qtm terraces followed by a ~200 ka record of aggradation. Qtm incision likely occurred near the LGM, prior to the onset of Qty fill terrace aggradation ~14 ka. Our terrace ages are broadly consistent with other regional fluvial terrace records, and comparison with available paleoclimatic archives suggests that terrace aggradation and incision occurred during drier and wetter hydrological conditions, respectively. Vertical bedrock incision rates were also calculated using OSL-derived estimates of Qtm strath planation and displayed statistically significant spatial variability with bedrock lithology, ranging from 0.04 mm/yr in the higher resistance reaches and 0.02 mm/yr in the lower resistance reaches. In combination with observations of valley width and terrace distribution, these results suggest that vertical processes outpace lateral ones in lithologic reaches with higher resistance.
Suggested Citation
Rodrigues, K., Keen-Zebert, A., Shepherd, S., Hudson, M., Bitting, C.J., Johnson, B.G., Langston, A., 2023, The role of lithology and climate on bedrock river incision and terrace development along the Buffalo National River, Arkansas: Quaternary Research, v. 115, p. 179-193, https://doi.org/10.1017/qua.2023.16.
Study Area
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | The role of lithology and climate on bedrock river incision and terrace development along the Buffalo National River, Arkansas |
| Series title | Quaternary Research |
| DOI | 10.1017/qua.2023.16 |
| Volume | 115 |
| Publication Date | May 26, 2023 |
| Year Published | 2023 |
| Language | English |
| Publisher | Cambridge University Press |
| Contributing office(s) | Geosciences and Environmental Change Science Center |
| Description | 15 p. |
| First page | 179 |
| Last page | 193 |
| Country | United States |
| State | Arkansas |
| Other Geospatial | Buffalo National River |