English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/95998
Compartir / Impacto:
Estadísticas
Add this article to your Mendeley library MendeleyBASE
Citado 9 veces en Web of Knowledge®  |  Pub MebCentral Ver citas en PubMed Central  |  Ver citas en Google académico
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar otros formatos: Exportar EndNote (RIS)Exportar EndNote (RIS)Exportar EndNote (RIS)
Título

Paleomagnetic and paleoenvironmental implications of magnetofossil occurrences in late Miocene marine sediments from the Guadalquivir Basin, SW Spain

Autor Larrasoaña, Juan C. ; Liu, Qingsong; Hu, Pengxiang; Roberts, Andrew P.; Mata, M. Pilar; Civis, Jorge; Sierro, Francisco J.; Pérez-Asensio, José N.
Palabras clave Guadalquivir Basin
Late Miocene
Magnetotactic bacteria
Marine sediments;
Messinian salinity crisis
Rock magnetism
Fecha de publicación mar-2014
EditorFrontiers Media
Citación Frontiers in Microbiology 5: 71-85 (2014)
ResumenAlthough recent studies have revealed more widespread occurrences of magnetofossils in pre-Quaternary sediments than have been previously reported, their significance for paleomagnetic and paleoenvironmental studies is not fully understood. We present a paleo- and rock-magnetic study of late Miocene marine sediments recovered from the Guadalquivir Basin (SW Spain). Well-defined paleomagnetic directions provide a robust magnetostratigraphic chronology for the two studied sediment cores. Rock magnetic results indicate the dominance of intact magnetosome chains throughout the studied sediments. These results provide a link between the highest-quality paleomagnetic directions and higher magnetofossil abundances. We interpret that bacterial magnetite formed in the surface sediment mixed layer and that these magnetic particles gave rise to a paleomagnetic signal in the same way as detrital grains. They, therefore, carry a magnetization that is essentially identical to a post-depositional remanent magnetization, which we term a bio-depositional remanent magnetization. Some studied polarity reversals record paleomagnetic directions with an apparent 60-70 kyr recording delay. Magnetofossils in these cases are interpreted to carry a biogeochemical remanent magnetization that is locked in at greater depth in the sediment column. A sharp decrease in magnetofossil abundance toward the middle of the studied boreholes coincides broadly with a major rise in sediment accumulation rates near the onset of the Messinian salinity crisis (MSC), an event caused by interruption of the connection between the Mediterranean Sea and the Atlantic Ocean. This correlation appears to have resulted from dilution of magnetofossils by enhanced terrigenous inputs that were driven, in turn, by sedimentary changes triggered in the basin at the onset of the MSC. Our results highlight the importance of magnetofossils as carriers of high-quality paleomagnetic and paleoenvironmental signals even in dominantly terrigenous sediments.
Versión del editorhttp://dx.doi.org/10.3389/fmicb.2014.00071
URI http://hdl.handle.net/10261/95998
DOI10.3389/fmicb.2014.00071
ISSN1664-302X
Aparece en las colecciones: (ICTJA) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
Cruz Larrasoaña 2014 frontiers in Microbiology 5 71 1.pdf3,02 MBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo
 



NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.