Séminaire ISTeP - Pierre Valla

(ETHZ – IDYST Lausanne)

Unravelling tectonics and surface processes in the exhumation history of South Alaska: insights from the thermochronological record

The St. Elias Range (southern Alaska) presents an ideal setting to study the complex interactions between tectonics, climate and surface processes. It exhibits active tectonics with the ongoing of subduction/collision between Pacific and North America, and major active seismogenic reverse and strike-slip faults. The alpine landscape, rugged topography and the important present-day ice-coverage reveal a strong glacial imprint associated with high erosion and sediment transport rates. Therefore, the relative importance of glacial erosion and tectonics for the observed late-exhumation history appears to be quite complex to decipher. The thermochronological record, including ~500 published low-temperature thermochronometric ages along the range, may provide useful constrains on the long-term St. Elias exumation history to discuss the relative influence of tectonic and climatic forcing.

14/11/2014 à 12h30, Salle Fourcade (Tour 55/56, 4ème étage)