Geochronology

SNSF SPARK Project

The recently introduced SNSF SPARK program is designed to fund proof-of-concept studies that develop novel ideas. The luminescence properties of quartz and feldspar minerals is determined by their chemical and structural composition, it thus follows that modifications to mineral chemistry should also affect the luminescence properties. In collaboration with Jasquelin Pēna and Stephanie Grand, this project will explore whether changes in the luminescence of quartz and feldspar can be provoked following sequential, laboratory chemical weathering. The ultimate objective is to create a novel proxy for total chemical weathering amount.

Team members involved: Georgina King (PI), Melanie  Bartz

ERC Starting Grant

Mountain ranges evolve in response to tectonic uplift, erosion and climatic change, but decoupling the feedbacks between these processes remains one of the most active debates in Earth Science. Resolving this debate is fundamental for successful projection of Earth’s surface response under a changing climate. The Impact of ClimatE on mountain Denudation (ICED) remains highly contested because no technique is available to resolve changes in erosion rates over the timescale of glacial-interglacial cycles i.e. 103-6 years, a key time range for quantifying the role that silicate weathering and denudation plays in modulating global climatic change. ICED will resolve this debate through establishing time-series of rock erosion over 103-6 years, allowing erosion rate changes to be related to specific climatic changes, and specific processes. These data will show whether tectonics or climatic feedbacks on surface processes are dominant in determining rates of surface denudation, providing insights into the influence of the lithosphere on global climatic change throughout the Quaternary period (ice age).

The objective of ICED will be achieved through the development and application of recently established thermochronometers based on the luminescence and electron spin resonance of quartz and feldspar minerals. Thermochronometers measure the rate of rock cooling, from which rates of rock exhumation and thus erosion rates can be calculated. Unlike existing methods, the new techniques developed within ICED are capable of resolving changes in erosion over timescales of between 103-6 years. Combining these new methods with cosmogenic nuclide data, using numerical models developed within ICED, will allow the generation of high-resolution time-series of erosion. These new techniques will be applied to the western European Alps.

Team members involved: Georgina King (PI), Lily Bossin