These contributions are authored by many of the foremost impact cratering researchers. This volume contains a sizable suite of contributions dealing with regional impact records (Australia, Sweden), impact craters and impactites, early Archean impacts and geophysical characteristics of impact structures, shock metamorphic investigations, post-impact hydrothermalism, and structural geology and morphometry of impact structures-on Earth and Mars. This volume represents the proceedings of the homonymous international conference on all aspects of impact cratering and planetary science, which was held in October 2019 in Brasília, Brazil. Magnetic properties of impact lithologies on Earth and extraterrestrial The particular amount in the studied sample and likely affects the Native iron strongly influences the magnetic properties, depending on Within molten pyrrhotite, quenched iron crystals occur. The sharp interfaces between molten andĬrystalline pyrrhotite document a rapid change of thermal conditions. Pressure release from 30 GPa finally triggers partial The planar deformation featuresĭisappear at 20 GPa and irregular, nanometer-sized "amorphous domains" Planar deformationįeatures subdivide such multidomain grains into lath-shaped domains withĪverage sizes lying in the SD range. Hardening is triggered by grain-size reduction, but also by theįormation of SD within discrete multidomain grains. Transition of monoclinic pyrrhotite broadens and is depressed. The λ-peak of hexagonal pyrrhotite decreases and the 34 K In agreement with more single-domain (SD)-like behavior. Magnetization and coercivity of remanence increase with shock pressures, Lower-pressure range coercivity, saturation isothermal remanent Pressures of 20 GPa and upward, amorphization and mechanical twinningĪre the dominant structural features induced by shock. Mechanical deformation producing a damage of the crystal structure. To 8 GPa, microstructures in shocked pyrrhotite are characterized by Microstructures and magnetic properties at high and low temperatures. Shock experiments with pressures ranging from 3 to 30 GPa have beenĬonducted on a mixed assemblage of hexagonal and monoclinic pyrrhotite.Īll samples were studied with respect to their particular shock-induced
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