Effect of Water Ice Transition on Murchison Meteorite

Friday, 19 December 2014
Helena Páchová1 and Gunther Kletetschka1,2, (1)Charles University in Prague, Faculty of Science, Prague, Czech Republic, (2)Academy of Sciences of the Czech Republic, Institute of Geology, Prague, Czech Republic
Uncertainty of magnetic field existence during formation of our solar system may be resolved by studying the details of carbonaceous meteorite. We chose Murchison meteorite to represent this group of carbonaceous meteorites.

Murchison contains magnetic minerals like magnetite and pyrhottite. Their presence suggests that there were oxidizing conditions during the formation of these two minerals. This material may have been exposed to water-ice proximity that caused neo-formation of these two minerals. Such chemical change in magnetic mineralogy may resulted from multiple exposure of the meteorite material to transition between the liquid and solid water (ice). We expose Murchison fragments to multiple cycles of water/ice transition. Our data shows changes in both magnetic susceptibility and remanence. We interpret these findings in terms of the past nebular magnetic fields.