Formation mechanisms of high-pressure phases in Martian meteorites

• Applicant: Dr. Ulrich W. Bläß
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2005 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 18510470

The proposed research project focuses on the formation of high-pressure phases in Martian meteorites. Such phases have recently been discovered in melt veins and pockets as well as in the bulk of these rocks. The occurrence of tiny grains of silicate hollandite, akimotoite, stishovite, silicate titanite and other high-pressure silicates in melt veins points to a crystallization of phases from quenched high-pressure melt. To account for the occurrence of high-pressure bulk phases such as (-PbO2 structured SiO2, presently unknown solid-state mechanisms are required. To develop crystallographic models for the mechanisms of high-pressure transformations, and to constrain cooling rates and shock conditions prevailing during the formation of high-pressure phases, we intend to perform a detailed analytical transmission electron microscope (TEM) study combined with thermodynamic modelling. The results will provide important implications for the formation of melt veins and pockets, and help to constrain the impact conditions that led to the ejection of SNC meteorites from Mars.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1115: Mars and the Terrestrial Planets
• Participating Person: Professor Dr. Falko Langenhorst