Searching for single domain magnetite in the “pseudo-single-domain” sedimentary haystack: implications of biogenic magnetite preservation for sediment magnetism and relative paleointensity determinations

Show simple item record Roberts, Andrew P. Liao, Chang Heslop, David Florindo, Fabio Larrasoaña Gorosquieta, Juan Cruz 2020-09-24T09:07:15Z 2020-09-24T09:07:15Z 2012-08-22
dc.identifier.citation Journal of Geophysical Research. Solid earth, vol.117, n.B8, 1-26 es_ES
dc.identifier.issn 2169-9356
dc.description.abstract Magnetic hysteresis measurements of sediments have resulted in widespread reporting of “pseudo‐single‐domain”‐like magnetic properties. In contrast, the ideal single domain (SD) properties that would be expected to be responsible for high quality paleomagnetic records are rare. Determining whether SD particles are rare or common in sediments requires application of techniques that enable discrimination among different magnetic components in a sediment. We apply a range of such techniques and find that SD particles are much more common than has been reported in the literature and that magnetite magnetofossils (the inorganic remains of magnetotactic bacteria) are widely preserved at depth in a range of sediment types, including biogenic pelagic carbonates, lacustrine and marine clays, and possibly even in glaci‐marine sediments. Thus, instead of being rarely preserved in the geological record, we find that magnetofossils are widespread. This observation has important implications for our understanding of how sediments become magnetized and highlights the need to develop a more robust basis for understanding how biogenic magnetite contributes to the magnetization of sediments. Magnetofossils also have grain sizes that are substantially smaller than the 1–15μm size range for which there is reasonable empirical support for relative paleointensity studies. The different magnetic response of coexisting fine biogenic and coarser lithogenic particles is likely to complicate relative paleointensity studies. This issue needs much closer attention. Despite the fact that sediments have been subjected to paleomagnetic investigation for over 60 years, much remains to be understood about how they become magnetized es_ES
dc.description.sponsorship National Oceanography Centre, University of Southampton, Reino Unido es_ES
dc.description.sponsorship Research School of Earth Sciences, Australian National University, Australia es_ES
dc.description.sponsorship Paleomagnetic Laboratory Fort Hoofddijk, Department of Earth Sciences, University of Utrecht, Holanda es_ES
dc.description.sponsorship Istituto Nazionale di Geofisica e Vulcanologia, Italia es_ES
dc.description.sponsorship Unidad de Zaragoza, Área de Cambio Global, Instituto Geológico y Minero de España, España es_ES
dc.language.iso en es_ES
dc.publisher American Geophysical Union es_ES
dc.relation NE/G003319/1 es_ES
dc.relation DP120103952 es_ES
dc.relation PR2011–0480 es_ES
dc.rights Acceso abierto es_ES
dc.subject magnetita es_ES
dc.subject magnetismo es_ES
dc.subject histérisis magnética es_ES
dc.subject propiedad magnética es_ES
dc.subject paleomagnetismo es_ES
dc.subject dominio magnético simple es_ES
dc.subject sedimento biogénico es_ES
dc.title Searching for single domain magnetite in the “pseudo-single-domain” sedimentary haystack: implications of biogenic magnetite preservation for sediment magnetism and relative paleointensity determinations es_ES
dc.type Postprint es_ES
dc.relation.publisherversion es_ES
dc.description.funder Natural Environment Research Council, Reino Unido es_ES
dc.description.funder Australian Research Council, Australia es_ES
dc.description.funder Ministerio de Educación y Cultura, España es_ES
dc.identifier.doi es_ES

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