Weathering is frequently the major process in soils formation, and clay minerals, as some of the most important soil components, control forming processes. Clays determine many soil properties, have a strong impact on soil fertility and thus have numerous fundamental relations to applied soil science. These are well-known facts, but many questions still remained to be solved.
In the last years there has been increasing interest for new topics that are worthy to emphasize. For example, clay minerals formation and transformation under surface conditions and the relationship with the biological factor are not still fully understood. Contributions on geochemistry and biogeochemistry of the weathering process are welcome.
The interpretation of clay minerals associations in soils (grouped into inherited, transformed and neoformed) is not an easy task. Biological factors, i.e. both living organisms and soil organic matter affect clay minerals, their evolution and properties. As a result, soil clay minerals are often not identical to their authigenic analogues. This session welcomes contributions on pedogenic clays and their specific properties (crystallography, chemistry, morphology) in different soil environments.
Interaction of clay minerals with soil natural polymers (soil humic substances) results in reciprocal change of their properties, but it also protects soil organic matter against leaching and degradation. Fractionation of soil organic substances due to the properties of a mineral matrix is the other facet of the interaction.
Clay minerals are known indicators of climate and paleoclimate. But the behaviour (stability and transformation) of clay minerals in paleosols under burial is often a matter of debate.
Soil mineralogists working in the field of paleopedology are welcome.