morphometry; erosion; quantitative geomorphology; earth surface geochronology; landscape evolution; tropical volcanic island; numerical modeling
Valla Pierre G., Lowick Sally E., Herman Frédéric, Champagnac Jean-Daniel, Steer Philippe, Guralnik Benny (2016), Exploring IRSL50 fading variability in bedrock feldspars and implications for OSL thermochronometry, in Quaternary Georchronology
, 36, 55-66.
King Georgina E., Herman Frédéric, Lambert Renske, Valla Pierre G., Guralnik Benny (2016), Multi-OSL thermochronometry of feldspar. Quaternary Geochronology, in Quaternary Georchronology
, 33, 76-87.
Diaz Nathalie, King Georgina E., Valla Pierre G., Herman Frédéric, Verrecchia Eric P. (2016), Pedogenic carbonate nodules as soil time archives: Challenges and investigations related to OSL dating, in Quaternary Geochronologx
, 36, 120-133.
Mandal Sanjay K., Lupker Maarten, Burg Jean-Pierre, Valla Pierre G., Haghipour Negar, Christl Marcus (2015), Controls on the spatial variability in 10Be denudation rates across the southern Peninsular Indian escarpment, in Earth and Planetary Science Letters
, 425, 154-167.
Qin Jintang, Chen Jie, Valla Pierre G., Herman Frédéric, Li Kechang (2015), Estimating rock cooling rates by using multiple luminescence thermochronometers, in Radiation Measurements
, 79, 13-18.
Enkelman Eva, Valla Pierre G., Champagnac J.-D. (2015), Low-temperature thermochronology of the Yakutat Plate corner, St. Elias Range (Alaska): bridging short-term and long-term deformation, in Quaternary Science Reviews
, 13, 23-38.
Guralnik Benny, Jain Mayank, Herman Frédéric, Ankjærgaard Christina, Murray Andrew S., Valla Pierre G., Preusser Frank, King Gerogina E., Chen Reuven, Lowick Sally E., Kook Myungho, Rhodes Edward J. (2015), OSL-thermochronometry of feldspar from the KTB borehole, Germany, in Earth and Planetary Science Letters
, 423, 232-243.
Guralnik Benny, Li Bo, Jain Mayank, Chen Reuven, Paris Richard B., Murray Andrew S., Li Sheng-Hua, Pagonis Vassilis, Valla Pierre G., Herman Frédéric (2015), Radiation-induced growth and isothermal decay of feldspar IRSL, in Radiation Measurements
, 81, 224-231.
Champagnac Jean Daniel, Valla Pierre G., Herman Frédéric (2014), Late-Cenozoic relief evolution under evolving climate: A review, in Tectonophysics
, 614, 44-65.
Rabin Mickael, Sue Christian, Valla Pierre G., Champagnac Jean-Daniel, Carry Nicolas, Bichet Vincent, Eichenberger Jacques, Mudry Jacques, Deciphering neotectonics from river profile analysis in the karstic Jura Mountains (European Alps), in Swiss Journal of Geosciences
Valla Pierre G., Rahn Meinert, Shuster David L., van der Beek Peter A., Multi-phase late-Neogene exhumation history of the Aar massif, Swiss central Alps, in Terra Nova
King Georgina E., Guralnik Benny, Valla Pierre G., Herman Frédéric, Trapped-charge thermochronometry and thermometry: A status review, in Chemical Geology
The Earth surface lies at the interface between the Lithosphere and Atmosphere, hence topographic evolution reflects the integrated response to interactions and feedbacks between endogenic (tectonics, volcanism) and exogenic (climate, sea-level variations) processes. Scientific research has mainly focused on active mountain ranges to explore these links, recent studies relying on developments in earth surface geochronology and modeling methods. However, deciphering the endogenic vs. exogenic contributions in mountain ranges evolution still appears difficult, in part due to the difference in characteristic timescale between the lithospheric (10^6-10^7 years) and atmospheric (10^4-10^5 years) processes. Tropical volcanic islands encompass similar interactions, with competing effects in their long-term evolution. Although these settings exhibit stunning landscapes and intense erosion dynamics, limited research has been dedicated to the interplay between volcanism, climate, and landscape evolution. Tropical volcanic islands are small-scale settings, with relative spatially uniform effusive basaltic/andesitic lithologies. They encompass a well-defined climatic forcing with stable tropical humid climate and a strong orographic precipitation pattern. Moreover, detailed information on volcanic forcing exists, with precise and independent knowledge of both the timing and spatial extent of effusive events through the dating of lava flow and shape reconstruction of initial volcanic edifice. Knowledge of the relative contributions of endogenic and exogenic forcing in island evolution makes them appropriate natural laboratories for investigating such interactions. However, erosion variability and geomorphic evolution remain there poorly constrained, in part due to limited application of earth surface geochronology tools. Quantifying landscape dynamics therefore requires further investigation to gain a better understanding of the landscape response to climatic and volcanic processes.Novel methodological developments in luminescence systems and in situ cosmogenic noble gas dating open new directions in earth surface geochronology applied to volcanic islands. The present project proposes to develop an integrated research program focused on the Réunion and Guadeloupe Islands as natural laboratories. They encompass similar climatic forcing (i.e. tropical humid climate with strong orography) but different volcanic dynamics: the Réunion Island displays continuous hot-spot basaltic volcanism, whereas andesitic arc activity has progressively migrated southward in the Guadeloupe Island. The present-day topographies of the two islands differ strongly, raising the question of how erosion and landscape respond to the respective contributions from climate and volcanic activity. The present project aims at developing a multi-disciplinary program at the University of Lausanne (Institute of Earth Sciences) to (1) quantify topographic evolution using luminescence thermochronometry, (2) address fluvial dynamics and catchment-scale erosion variability using luminescence and in situ cosmogenic noble gas surface exposure dating, and (3) explore the interactions between tropical climate, volcanic activity and earth surface processes using morphometry and state-of-the-art numerical modeling. This is of prime importance to quantitatively explore the causal links and feedbacks between the Lithosphere, Atmosphere and landscape dynamics in volcanic island evolution. The proposed project will lead first to a better understanding of how the different earth surface processes interact in volcanic island landscape evolution. The Réunion and Guadeloupe Islands settings are appropriate natural laboratories to quantitatively explore how erosion and landscape respond to the respective endogenic and exogenic forcing. Quantitative erosion data will fill the existing gap between integrated eroded volumes deduced from shape reconstructions and present-day to decadal sediment fluxes or geochemical estimates. This will allow to fully explore the causal links and strong feedbacks existing between climate, volcanism and landscape dynamics in such environments, and will bring new ideas and physical concepts that would be tested in more complex mountain ranges. Moreover, this project has important societal interests. Tropical volcanic islands experience low-frequency events, such as tropical storms or volcanic eruptions, which are extremely difficult to forecast but have considerable impact on human habitability. The understanding and quantification of landscape response to these extreme events will have valuable consequence on natural hazards and risk assessment. Finally, volcanic islands are major components in global weathering and atmospheric carbon flux regulations, therefore requiring a better quantification of long-term erosion. The multi-disciplinary project promotes the application of modern and innovative quantitative methods in earth surface geochronology to volcanic settings, with a special attention to further methodological development for both thermochronometry and surface exposure dating. The research plan also includes strong national (University of Lausanne and University of Bern) and international collaborations, providing high visibility to the project within the Geosciences community.