La susceptibilidad magnética como marcador paleoambiental en un abanico aluvial del Pleistoceno superiorla cuenca de Añavieja, Cordillera Ibérica (NE de España)
- B. Oliva Urcia 1
- J.C. Larrasoaña 2
- A. Muñoz 3
- A. González 3
- A. Pérez 3
- A. Luzón 3
- T. Román Berdiel 3
- J.J. Villalaín 4
- 1 Instituto Pirenaico de Ecología, CSIC
- 2 IGME
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3
Universidad de Zaragoza
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4
Universidad de Burgos
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ISSN: 1576-5172
Ano de publicación: 2012
Título do exemplar: VIII Congreso Geológico de España, Oviedo, 17-19 de julio, 2012.
Número: 13
Páxinas: 742-745
Tipo: Artigo
Outras publicacións en: Geotemas (Madrid)
Resumo
Standard mineral magnetic measurements including magnetic susceptibility, anhysteretic remanent magnetization and isothermal remanent magnetization are of common use in environmental magnetism to detect climatic changes. In the case of Añavieja Basin, the magnetic susceptibility was measured in 610 points from Pleistocene sediments from an alluvial system cut in a 25.3 m drilled core in NE of Spain. In addition, the magnetic susceptibility normalized by mass was measured in 390 discrete standard samples that were sampled every 5 cm along the core. The recorded magnetic signal and the 14C dating allow establishing precisely paleoenvironmental changes in a system with a sedimentation rate of ∼2 mm/year. The magnetic susceptibility works as a proxy for climate variations because the alluvial fan sediments acquire a specific magnetic signature as a consequence of draining processes. Detrital input depends mainly on the strength/quantity of the rainfall and runoff. The curves of magnetic susceptibility and changes in δ18O values show a good correlation, so that higher values of magnetic susceptibility, which are due to higher content of maghemite (identified through thermomagnetic analyses) is concordant with warmer, and wetter times.
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