Approaching the Petrophysics of deep Earth’s and Earth-like Planetary Interior

Abstract:

The Earth’s deep interior is only accessible by indirect methods, first and foremost seismological studies. The interpretation of these seismic data and the corresponding numerical modelling require measurements of the elastic and inelastic properties of representative Earth materials under experimental simulated in-situ pressure-temperature conditions. Seismic tomography studies and corresponding numerical models have demonstrated that under certain conditions subducting slabs can even reach the core mantle boundary. That means former crustal rocks became heavily overprinted by increasing pressure, temperature, deformation and partial material exchange. Because there is no known geodynamic mechanism able to bring them back to the surface as a whole, we cannot sample them. But there is no indication to assume they are simpler than their parental rocks - quite the contrary. I think the first-order future challenge for large volume geophysical high pressure research is to measure data for an understanding of the relation between structural and physical properties of these complex polymineral rock-like assemblages. The paper presents the results of petrophysical transient experiments with natural rocks under uppermost mantle conditions and first steps to perform in-situ experiments under deep mantle conditions.