Experimental deformation of (Mg,Fe)O ferropericlase at high-pressure and simultaneously high-temperatures

• Applicant: Dr. Hauke Marquardt
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 275722583

(Mg,Fe)O ferropericlase is the second most abundant mineral of Earths lower mantle. It is considered to be rheologically weaker than bridgmanite, the most abundant mineral of the lower mantle. This relative weakness can lead to strain partitioning into ferropericlase in large strain areas of the mantle, such as in boundary layers or areas around subducting slabs. In this scenario, the deformation behavior of ferropericlase will govern the bulk deformation of the mantle. This proposal aims at studying the deformation behaviour of (Mg,Fe)O ferropericlase at simultaneously high-pressure and high-temperatures, approaching the conditions relevant to Earths lower mantle. Measurements will be performed by using synchrotron radial x-ray diffraction in a graphite resistive-heated diamond-anvil cell employing a dedicated experimental setup that is now available at the Extreme Conditions Beamline of PETRA III (DESY). The expected outcome will impact on several key questions regarding the structure and dynamics of Earths lower mantle, including the fate of subducting slabs and the interpretation of seismic anisotropy observations in the D`` layer above the core mantle boundary.

• DFG Programme: Research Grants
• International Connection: France, USA
• Cooperation Partners: Professor Dr. Sébastien Merkel; Professor Dr. Lowell Miyagi
• Co-Investigators: Hanns-Peter Liermann, Ph.D.; Dr. Katharina Marquardt; Dr. Sergio Speziale