Mantle–surface coupling through regional tectonics, geochemical constraints, landscape evolution, and the carbon cycle

Understanding the imprint of deep Earth processes on surface landscape evolution remains a major challenge in Earth sciences. While tectonic uplift, physical erosion, drainage basin organization, and chemical weathering are commonly interpreted through crustal tectonics, surface geomorphology and cosmogenic nuclides, growing geophysical imaging evidence shows that mantle dynamics, including slab rollback, tearing, detachment, and asthenospheric plume-driven dynamic topography, can strongly influence vertical motions, deep fluid pathways, solute fluxes, and the carbon cycle at Quaternary timescales.

In this presentation, I show how critical zone processes can be used as quantitative proxies of deep Earth dynamics by integrating geomorphology, geochemistry, and landscape evolution modelling across contrasting tectonic and lithological settings. Results from the ANR PALAVAS project on the tropical volcanic island of Basse-Terre (Guadeloupe) reveal extreme silicate weathering efficiency and high denudation and CO₂ consumption rates that are closely controlled by volcanic edifice growth, rainfall patterns, landscape evolution, and regolith dynamics. This silicate-weathering endmember is contrasted with the carbonate-dominated, tectonically active margin of the Aegean domain. There, Mount Olympus massif, which is located in a back-arc extensional basin 200km north of the Corinth Rift and near the northern limit of the Aegean slab-detachment zone, shows limited post-Miocene thermochronologic cooling, rapid Quaternary uplift, strong glacial and fluvial landscape reorganization, and alpine soils enriched in chrome-spinel and detrital zircon, indicating deep lithospheric inheritance linked to active tectonics.

Despite similar Quaternary uplift rates (~1–1.5 mm/yr) between Corinth Rift and Mount Olympus massif over the last ~250 kyr, their contrasting structural styles suggest fundamentally different driving mechanisms, pointing to a mantle-driven component of uplift in the central Aegean supported by recent geophysical imaging. Karst hydrochemistry, alpine soil mineralogy, Sr–Nd isotopes, cosmogenic nuclides, and landscape evolution modelling are used to test whether deep CO₂ transfer and mantle forcing modulate uplift and carbonate dissolution above the slab-detachment zone. Taken together, these case studies demonstrate that critical zone processes, including landscape evolution, soil development, karst fluid geochemistry, and sediment deposition, act as integrated recorders of deep Earth forcing and are tightly coupled with long-term carbon-cycle feedbacks.