
Andreas Nilsson
Universitetslektor

Magnetostratigraphic importance of secondary chemical remanent magnetizations carried by greigite (Fe3S4) in Miocene sediments, New Jersey shelf (IODP Expedition 313)
Författare
Summary, in English
Paleomagnetic and mineral magnetic analyses were carried out on Miocene clays from upper unit II at Sites M0027 and M0028 recovered during Integrated Ocean Drilling Program Expedition 313 on the New Jersey shallow shelf. A zone of mixed polarity in the lower section of Hole M0028A and dual overlapping magnetization components in upper Hole M0027A indicate that the sediments may have been chemically remagnetized during one or several events. Mineral magnetic investigations reveal that the magnetization is carried by the ferrimagnetic iron-sulfide greigite (Fe3S4), possibly with traces of titano-magnetite. We find that several changes in polarity coincide with variations in magnetic mineral grain size and/or concentration. We interpret these variations as different stages of greigite growth, which were triggered by changes in pore-water chemistry and/or upward migration of methane.
Avdelning/ar
- Kvartärgeologi
Publiceringsår
2013
Språk
Engelska
Sidor
510-520
Publikation/Tidskrift/Serie
Geosphere
Volym
9
Issue
3
Dokumenttyp
Artikel i tidskrift
Förlag
Geological Society of America
Ämne
- Geology
Aktiv
Published
ISBN/ISSN/Övrigt
- ISSN: 1553-040X