Climatic Controls on Erosion Rates and Relief of Mountain Belts

ongoing

Quantifying the feedbacks between tectonic processes in the lithosphere and climatic processes in the atmosphere is an overarching goal in Earth-Systems research, as it underpins our ability to differentiate natural from anthropogenic climate forcing. Long-term cooling during the Cenozoic has been linked to the growth of mountain belts, which enhanced erosion, chemical weathering, organic-carbon burial and drawdown of atmospheric CO2. Conversely, it has been proposed that the cooler and more variable climate of the late Cenozoic led to increased topographic relief and erosion. This latter coupling, however, has not been decisively demonstrated and remains highly controversial. Advancing our understanding of these couplings requires the development of tools that record erosion rates and relief changes with higher spatial and temporal resolution than the current state-of-the-art, and integrating the newly obtained data into next-generation numerical models that link observed erosion-rate and relief histories to potential driving mechanisms. The project COOLER shoulders this task. We will: (1) develop new high-resolution thermochronology by setting up a world-leading 4He/3He laboratory; (2) develop numerical modelling tools that incorporate the latest insights in kinetics of thermochronological systems and make sample-specific predictions; (3) couple these tools to glacial landscape-evolution models, enabling modelling of real landscapes with real thermochronology data as constraints; and (4) study potential feedbacks between glacial erosion and tectonic deformation in carefully selected field areas. The new high-resolution data will be integrated and extrapolated to quantitatively assess the impact of late Cenozoic climate change on erosion rates. Integration and analysis of the data will lead to novel insights into the two-way coupling of glacial erosion and tectonics, as well as latitudinal trends in glacial erosion patterns.