Probing a Hydrous Iron-Sulfate Within Extreme Planetary Environments

Olivia Pardo, California Institute of Technology

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High-pressure experimental techniques create the extreme physical environments necessary to explore properties of materials relevant to Earth and other planetary bodies. The diamond-anvil cell is a versatile device capable of achieving both static and dynamic compression at a range of temperatures. Szomolnokite, a hydrous iron-sulfate, is an endmember of an extensive mineral group observed on Earth, Mars, and the icy satellites. I present a culmination of diamond-anvil cell work utilizing synchrotron radiation to measure the structural, vibrational, and electronic properties of szomolnokite at previously unstudied combinations of pressure and temperature. Using X-ray diffraction, and synchrotron Mössbauer and infrared spectroscopy, I identify two crystal structural phase transitions characterized by Fe-octahedral site distortion and potentially reversible behavior upon decompression. These results support this mineral’s ability to retain water within deep planetary interiors and upon recycling back to the surface.

Abstract Author(s): Olivia S. Pardo, Vasilije V. Dobrosavljevic, Tyler Perez, Wolfgang Sturhahn, Zhenxian Liu, George R. Rossman, Thomas S. Toellner, Jennifer M. Jackson