DFG SPP 1236

Our Section is participating in Priority Program 1236 (SPP1236) funded by the German Science Foundation (DFG). The projects sited at the GFZ are particularly focused on studying the Earth’s water cycle and its effect on the structure and dynamic of the Earth. The studies involve high-pressure experiments (multi-anvil, partly synchrotron-based) coupled with detailed phase characterization (X-ray diffraction, IR, HRTEM-AEM, Brillouin-spectrocopy) as well as computer simulations of crystal structures using atomistic theories.

The following projects are carried out in the second period 2009-2012:

Effect of water in wadsleyite and ringwoodite on the P-T-x coordinates of the wadsleyite-ringwoodite phase transformation: an experimental and thermodynamic study

The goals of this project are  

• to investigate the effect of water on the P-T-x coordinates of the wadsleyite-ringwoodite phase transition in quenched multi-anvil experiments,
• to experimentally determine the fractionation of water between coexisting wadsleyite and ringwoodite at the phase boundary,
• to characterize the run products in respect to structure (structural defects, inversion degree) and crystal chemistry,
• to characterize the vibrational behavior of hydrous wadsleyite and ringwoodite experimentally.

Determination of single-crystal elastic properties of olivine and serpentine as a function of chemical composition at conditions of subduction zones up to 25 GPa, 1000°C

We are studying the elastic properties of single-crystal olivine and of antigorite at conditions relevant for the subducted oceanic lithosphere up to 600 km depth along various pressure-temperature profiles corresponding to different subduction geometries.