Back to Search Start Over

Quantifying magnetite magnetofossil contributions to sedimentary magnetizations

Authors :
Liao Chang
Alexandra Abrajevitch
Andrew P. Roberts
Patrick De Deckker
David Heslop
Maureen Davies
Source :
Earth and Planetary Science Letters, 382, 58. Elsevier
Publication Year :
2013

Abstract

Under suitable conditions, magnetofossils (the inorganic remains of magnetotactic bacteria) can contribute to the natural remanent magnetization (NRM) of sediments. In recent years, magnetofossils have been shown to be preserved commonly in marine sediments, which makes it essential to quantify their importance in palaeomagnetic recording. In this study, we examine a deep-sea sediment core from offshore of northwestern Western Australia. The magnetic mineral assemblage is dominated by continental detritus and magnetite magnetofossils. By separating magnetofossil and detrital components based on their different demagnetization characteristics, it is possible to quantify their respective contributions to the sedimentary NRM throughout the Brunhes chron. In the studied core, the contribution of magnetofossils to the NRM is controlled by large-scale climate changes, with their relative importance increasing during glacial periods when detrital inputs were low. Our results demonstrate that magnetite magnetofossils can dominate sedimentary NRMs in settings where they are preserved in significant abundances.

Details

Language :
English
ISSN :
0012821X
Volume :
382
Database :
OpenAIRE
Journal :
Earth and Planetary Science Letters
Accession number :
edsair.doi.dedup.....4c57f83965501ee596fe6ee4df3da0a3