Riesite, a New High Pressure Polymorph of TiO2 from the Ries Impact Structure
Oliver Tschauner, Chi Ma, Antonio Lanzirotti, M. Newville
Abstract
This paper describes riesite, a new high-pressure polymorph of TiO2 from the Ries impact structure, Germany. Riesite occurs in shock-induced melt veins within xenoliths of bedrock in suevite. It is structurally closely related to srilankite from which it differs by having two distinct cation sites rather than one and through its monoclinic symmetry. It is indicative that riesite forms only upon release from the shock state upon back transformation from akaogiite.
Topics & Concepts
Monoclinic crystal systemShock (circulatory)BedrockShock metamorphismGeochemistryImpact structureHigh pressureGeologyCrystallographyMaterials scienceCrystal structureChemistryMineralogyThermodynamicsPhysicsImpact craterMedicineGeomorphologyAstronomyInternal medicineGeological and Geochemical AnalysisHigh-pressure geophysics and materialsearthquake and tectonic studies