SESSION 1

EARTH SURFACE PROCESSES BEYOND CLIMATE FORCING: Autogenic Surface Processes and Their Impact on Sedimentary Archives and Local Environments

Carlo Mologni ¹, Emmanuel Chapron ², Mathieu Schuster ³

 1 - GEOAZUR-UMR7329, Univ. Côte d’Azur, CNRS, OCA, IRD, Valbonne.

2 - GEODE-UMR5602, CNRS, Univ. Jean Jaurès, Toulouse.

3 - ITES-UMR7063, CNRS, Université de Strasbourg, Strasbourg.

carlo.mologni@geoazur.unice.fr

This session explores the influence of physical and biogeochemical processes in shaping hydrological pedological and morpho-sedimentary patterns of the Earth’s surface that operate independently of climatic or atmospheric forcing. These processes, referred to as autogenic or non-linear, are characterized by a disproportionate response to the external forcing that triggers them and can have a significant, even major, impact on ecosystems at the local scale.

For example, in geomorphology, the activation or deactivation of an overflow threshold between two lake basins can modify their hydro-sedimentary balance. In soil systems, the availability or the depletion of weatherable minerals, nutrients, or vegetation can alter rates of chemical weathering and/or erosion. In paleolimnology, the migration of a confluence delta during a shoreline regression may result in a disproportionate sedimentation rate at the depocenter site, despite a decrease in precipitation. These processes can influence: a) the sensitivity and/or integrity of continuous sedimentary archives such as lake deposits, b) tipping points, threshold effects, hiatuses, or xenoconformities observed within continuous sedimentary archives, and c) the establishment or persistence of local ecosystems independently of global climatic conditions (e.g., refugia areas).

We invite contributions addressing all autogenic mechanisms of the Earth’s surface, as well as their broader context within the Critical Zone, that are capable of influencing water availability, soil systems functioning, morpho-sedimentary evolution, and the integrity of continuous climate archives. Case studies, conceptual or modeling approaches from hydrology, geomorphology, sedimentology, geochemistry, soil science, and biology are welcome, with the aim of better understanding the non-linear relationships between climate and the Earth’s surface, including ecosystem dynamics.

Keywords: Climate-Earth surface decoupling; autogenic processes; hiatus; tipping points; thresholds effects, pedo-sedimentary anomalies, xeno- / non-conformities.