Measuring the elastic properties of natural rocks and mineral assemblages under Earth's deep crustal and mantle conditions

The direct access to the interior of our planet is very limited. Scientific drilling can reach about 15 km depth. Natural exhumation processes in conjunction with orogeny bring massive rock packages from up to 100 km depth back to surface. Explosion breccia and kimberlite pipes can carry small rock and mineral fragments as xenoliths from up to 250 km depth. But all the detailed knowledge we achieved about Earth's deep interior structures and dynamics, especially during the last two decades is based on highly resolved seismic data, in particular seismic tomography. That means it is a three-dimensional distribution of elastic and inelastic data with the maximum resolution of the seismic wavelength, i.e. at great depth several kilometres in principle. Consequently any material information is a matter of interpretation. Thus a detailed knowledge about the elastic properties of rocks in dependence on pressure, temperature, mineral content, grain size, deformation, crack distribution, etc., is crucial for this interpretation.