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| Titel |
Predicting thermochronological data from a fluvio-glacial surface process model |
| VerfasserIn |
Vivi Kathrine Pedersen, David Lundbek Egholm, Jean Braun, Frédéric Herman, Søren Bom Nielsen |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250051694
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| Zusammenfassung |
| Consistency between thermochronological parameters measured on rock samples
and those obtained from physically based surface process models is a prerequisite
for improving our quantitative understanding of long-term surface processes and
to infer the long-term topographical evolution of an area under varying climate
conditions.
Here we combine surface process model results with a thermal solver, in order to
investigate the thermochronological responses to fluvial vs. glacial landscape evolution. We
use iSOSIA, a higher-order ice-sheet model coupled with fluvial erosion and hillslope mass
wasting, for simulating fluvio-glacial erosion.
In order to quantify the thermal effects of the predicted surface erosion, and calculate
different thermochronological parameters, we use Pecube, a finite element code that solves
the transient heat transport equation in three dimensions, including heat conduction,
advection and production.
We investigate the predictions of two of the most low-temperature thermochronological
methods: 1) apatite helium (AHe) ages, sensitive to temperatures in a range from 40-70oC,
and 2) optically stimulated luminescence (OSL) ages, with a closure temperature of about
30-35oC. These two methods may potentially resolve the small exhumation differences
caused by changes in dominant surface process.
In this study we focus on the thermochronological response of cyclic glacial erosion in
steady-state fluvial orogens dominated by different rates of tectonic uplift. We show how the
predicted AHe and OSL ages vary both spatially and temporally, and investigate how they
each relate to the assumed efficiency of the erosional processes, as well as the climate
forcing, in relation to the different uplift rates. |
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