Berlin 2014 – wissenschaftliches Programm
MS 9.3: Vortrag
Donnerstag, 20. März 2014, 14:45–15:00, DO24 1.205
Search for supernova-produced 60Fe in the microfossil record — •Peter Ludwig1, Shawn Bishop1, Ramon Egli2, Valentyna Chernenko1, Thomas Faestermann1, Nicolai Famulok1, Leticia Fimiani1, Thomas Frederichs3, Jose Gomez1, Karin Hain1, Marianne Hanzlik4, Gunther Korschinek1, Silke Merchel5, and Georg Rugel5 — 1TU München, Physik Department — 2ZAMG, Wien — 3Universität Bremen, Geowissenschaften — 4TU München, Fakultät für Chemie — 5HZDR, Dresden
Material distributed into the interstellar medium by supernova explosions can be incorporated into terrestrial archives. After the discovery of live 60Fe atoms in 2-3 Myr old layers of a Pacific Ocean ferromanganese crust (Knie et al., PRL 93, 171103 (2004)), a confirmation of this signal, as well as a mapping of the signal with high time-resolution is desireable. Another reservoir in which the 60Fe signature should have been incorporated are the fossils of magnetotactic bacteria in ocean sediment. To this end, two sediment cores from the Eastern Equatorial Pacific were obtained, iron was chemically extracted with high selectivity towards biogenic magnetite, and the extraction procedure was characterized using novel magnetic measurements. The 60Fe/Fe concentration in the samples was then measured with accelerator mass spectrometry at the GAMS setup in Garching. Preliminary results for both sediment cores will be reported.