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Surface & Lithosphere

 

Coordinator : Philippe Hervé Leloup

Research area :
 

The interaction of processes that redistribute the matter within the lithosphere and at the surface shapes the Earth's surface morphology and its evolution. At the surface, erosion, influenced by climate, shapes the reliefs and feeds the sedimentation zones. At depth, the mantle convection induces large-scale motions and deformations that influence the thermal state of the lithosphere. These mechanisms often show complex retroactions. For example, strong vertical motions imply fast erosion and strong reliefs. However these reliefs influence the local climate that is the main player of erosion whose efficiency depends of altitude. It is even envisaged that a focussed increase of erosion, for example due to a climatic change, could induce strong vertical motions affecting the mantle convection. Characterisation of the relief evolution thus necessitates a better understanding of these complex interactions between external and internal processes.

Some of the basic mechanisms of the relief evolution are still poorly understood because they are intermittent and their quantification depends on the observation timescale. For example erosion rates are not the same whether measured during heavy rain or averaged over several years. The way precise short-term measurements can be extrapolated over long-time scales of several thousands or even millions of years is thus questionable. In a similar way, geologic archives preserve long-term information but with possible large gaps and a lack of precision.




 

To better understand the mechanisms of mountain building and plate-tectonics we combine field-data acquisition and large-scale numerical models (European AUGURY project leaded by Nicolas Coltice).

To characterize erosion and sedimentation dynamics we combine the study of present-day sedimentation and sedimentary geological archives.

Participants in the theme :

Researchers, teacher-researchers, engineers & technicians:

ALLEMAND Pascal (Pr)
COLTICE Nicolas (Pr)
GARDIEN Véronique (MCF)
GRANDJEAN Philippe (Tech)
LANGLOIS Vincent (MCF)
LELOUP Philippe-Hervé (DR)
MAHEO Gweltaz (MCF)
MARTELAT Jean-Emmanuel (MCF)
METOIS Marianne (MCF)
PASSOT Sophie (IE)
PFEFFER Julia (Post Doc)
PITTET Bernard (MCF)
SORREL Philippe (MCF)

PhD students :
GUILLERM Emmanuel
RAGON Maxime

Four-year project (In french) :
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