Clays in the Critical Zone: soils, weathering and elemental cycling

The “Critical zone" or CZ, includes the porous places extending from treetops to the bedrock, and more especially soils where organisms interact and shape the Earth’s surface over timescales from seconds to eons. Clay minerals and finely divided oxides are significant players within the CZ. In particular, they are known to be key in the fate of elements (both nutrients - including carbon - and pollutants) and molecules (e.g. pesticides but also drugs such as antibiotics). This session seeks contributions regarding chemical and structural characterization of clay sorption properties, sorption mechanisms of these species on clays, and structural modifications induced by the interactions of clays with these elements and molecules. The session will also welcome contributions that examine, at a more global scale, clays and their role in life-sustaining matters, such as water quality, land use, carbon cycling, soil quality, contaminant transport, weathering and climate change. In essence, ‘How do clays help us to understand CZ functions and how will the CZ change into the future?’.