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dc.contributor.authorKontny, A.
dc.contributor.authorElbra, T.
dc.contributor.authorJust, J.
dc.contributor.authorPesonen, L. J.
dc.contributor.authorSchleicher, A. M.
dc.contributor.authorZolk, J.
dc.date.accessioned2021-02-12T22:54:25Z
dc.date.available2021-02-12T22:54:25Z
dc.date.issued2007-01-01
dc.identifier.citationKontny, A., Elbra, T., Just, J., Pesonen, L. J., Schleicher, A. M., & Zolk, J. (2007). Petrography and shock‐related remagnetization of pyrrhotite in drill cores from the Bosumtwi Impact Crater Drilling Project, Ghana. Meteoritics & Planetary Science, 42(4‐5), 811-827.
dc.identifier.issn1945-5100
dc.identifier.doi10.1111/j.1945-5100.2007.tb01077.x
dc.identifier.urihttp://hdl.handle.net/10150/656709
dc.description.abstractRock magnetic and magnetic mineralogy data are presented from the International Continental Scientific Drilling Program (ICDP) drill cores LB-07A and LB-08A of the Bosumtwi impact structure in order to understand the magnetic behavior of impact and target lithologies and their impact-related remagnetization mechanism. Basic data for the interpretation of the magnetic anomaly patterns and the magnetic borehole measurements as well as for new magnetic modeling are provided. Magnetic susceptibility (150-500 10^)-6) SI) and natural remanent magnetization (10^(-3)-10^(-1) A/m) are generally weak, but locally higher values up to 10.6 x 10^(-3) SI and 43 A/m occur. Sixty-three percent of the investigated rock specimens show Q values above 1 indicating that remanence clearly dominates over induced magnetization, which is a typical feature of impact structures. Ferrimagnetic pyrrhotite is the main magnetite phase, which occurs besides minor magnetite and a magnetic phase with a Curie temperature between 330 and 350 degrees C, interpreted as anomalous pyrrhotite. Coercive forces are between 20 and 40 mT. Brecciation and fracturing of pyrrhotite is a common feature confirming its pre-impact origin. Grain sizes of pyrrhotite show a large variation but the numerous stress-induced nanostructures observable by transmission electron microscopy (TEM) are assumed to behave as single-domain grains. We suggest that the drilled rocks lost their pre-shock remanence memory during the shock event and acquired a new, stable remanence during shock-induced grain size reduction. The observed brittle microstructures indicate temperatures not higher than 250 degrees C, which is below the Curie temperature of ferrimagnetic pyrrhotite (310 degrees C).
dc.language.isoen
dc.publisherThe Meteoritical Society
dc.relation.urlhttps://meteoritical.org/
dc.rightsCopyright © The Meteoritical Society
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjectmagnetic properties
dc.subjectremagnetization mechanism
dc.subjectBosumtwi Ghana impact crater
dc.subjectPyrrhotite
dc.titlePetrography and shock-related remagnetization of pyrrhotite in drill cores from the Bosumtwi Impact Crater Drilling Project, Ghana
dc.typeArticle
dc.typetext
dc.identifier.journalMeteoritics & Planetary Science
dc.description.collectioninformationThe Meteoritics & Planetary Science archives are made available by the Meteoritical Society and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.
dc.eprint.versionFinal published version
dc.description.admin-noteMigrated from OJS platform February 2021
dc.source.volume42
dc.source.issue4-5
dc.source.beginpage811
dc.source.endpage827
refterms.dateFOA2021-02-12T22:54:25Z


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