This session is concerned with studies of the thermodynamic and structural behavior of clays under non-ambient conditions. Collecting data under non-ambient conditions often imposes significant additional complexities in the data-collection and data-handling procedures than are necessary in ambient studies. Two kinds of approach can be used: in situ investigations and "quench-and-look" investigations. The "quench-and-look" approaches tend to focus upon compositional systematics; however, many materials undergo non-quenchable displacive phase transitions at high pressure and high temperature, which possibly lead to microtexture formation and anomalous thermodynamic behavior. The determination of compressibilities and expansivities provides fundamental thermodynamic data and allows the behavioral trends to be identified between structurally and compositionally related phases. The use of pressure or temperature assemblies (DACs, multi-anvil devices, cryostats, furnaces) for structural purposes often requires access to non-conventional sources (e.g. synchrotron and neutron sources).
Besides having promising applications in the fields of nanosciences and nanotechnologies for biology and medicine, layer silicates are reliable predictors for petrogenetic conditions and evolution paths in sedimentary systems; they also play a key role in water and light element transportation and recycling in high temperature, high pressure subduction environments.
Studies on physical properties of clays in non-ambient conditions are thus fundamental in understanding and interpreting natural Earth-scale events as well as nano-scale structural behaviour of these materials.
In the light of previous considerations, contributions are welcome on quenching and in situ experimental studies leading to the assessment of non-ambient physical properties of any suitable species of layer silicates.