Experimental tests of geobarometers and oxybarometers for volatile-bearing model peridotites at Earth’s upper mantle conditions

Reconstructing redox conditions within the Earth’s mantle is an essential step in understanding large-scale material and volatile cycles between the Earth's outer envelopes and its deep interior. The study is designed to test the reliability and accuracy of previous geobarometers and oxybarometers for a suite of model volatile-bearing peridotitic rocks at Earth’s upper mantle conditions up to the transition zone. The mantle rocks will be synthesized by the large volume press combined by in-situ XRD at ID06. The oxidation state of Fe in the mineral and melt phases of the synthesized samples will be then determined by latest breakthroughs of the synchrotron Moessbauer spectroscopy at ID18. The establishment of an internally-consistent cross calibration of previous oxybarometers will allow improvements in fundamental models used to predict the depth and redox conditions of natural peridotitic upper mantle lithologies, including peridotitic mineral inclusions in diamonds.