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| Titel |
Paraglacial fluvial bedrock incision in postglacial landscapes: the NW Scottish Highlands |
| VerfasserIn |
Katie Whitbread, John Jansen, Paul Bishop, Derek Fabel |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250039205
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| Zusammenfassung |
| Glacial landscape forms are inherited by rivers following deglaciation. Hillslopes and valley
floors configured by glacial erosion control the distribution of bedrock channels and potential
sites for fluvial incision. The importance of ‘stream power’ parameters, channel slope and
drainage area (discharge), in controlling the rate of incision is widely accepted, but the rate,
timing and mechanisms of incision have yet to be quantified in these settings. The dual
controls of glacially conditioned bedrock slopes and sediment supply set two of the key
boundary conditions for temporally and spatially dynamic fluvial bedrock incision.
Measurement of incision rates in these settings is key to understanding the influence of
controls on fluvial erosion, and the role of the process in long-term evolution of deglaciated
landscapes.
In tectonically-passive, hard-rock terrains, such as the Scottish Highlands, incisional
fluvial features such as bedrock channels, gorges and waterfalls are common on glacially
carved valley steps. Here we report preliminary data on fluvial incision rates measured with
cosmogenic 10Be. Our results confirm a postglacial age of bedrock straths in the NW Scottish
Highlands and indicate a vertical incision rate of 0.3 mm/yr into resistant quartzites. Further
work will explore erosion mechanisms and rates of incision across the Scottish Highlands,
and assess controls on fluvial incision, including the potential role of paraglacial sediment. |
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