Response of alluvial systems to Late Pleistocene climate changes recorded by environmental magnetism in the Añavieja Basin (Iberian Range, NE Spain)

Authors

  • B. OLIVA URCIA Instituto Pirenaico de Ecología, CSIC Avda. Montañana 1005, 50059 Zaragoza, Spain Dpto. de Geología y Geoquímica, Universidad Autónoma de Madrid Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain
  • A. MUÑOZ Dpto. ciencias de la Tierra. Universidad de Zaragoza, Área de Estratigrafía Pedro Cerbuna, 12, 50009 Zaragoza, Spain
  • J.C. LARRASOAÑA Instituto Geológico y Minero de España (IGME) Manuel Lasala, 49, 50006 Zaragoza, Spain Institute of Earth Sciences Jaume Almera, ICTJA-CSIC Solé i Sabarís s/n, 08028 Barcelona, Spain
  • A. LUZÓN Dpto. ciencias de la Tierra. Universidad de Zaragoza, Área de Estratigrafía Pedro Cerbuna, 12, 50009 Zaragoza, Spain
  • A. PÉREZ Dpto. ciencias de la Tierra. Universidad de Zaragoza, Área de Estratigrafía Pedro Cerbuna, 12, 50009 Zaragoza, Spain
  • Á. GONZALEZ Dpto. ciencias de la Tierra. Universidad de Zaragoza, Área de Estratigrafía Pedro Cerbuna, 12, 50009 Zaragoza, Spain
  • Z. JIANG Paleomagnetism and Geochronology Laboratory, Institute of Geology and Geophysics, chinesse Academy of Sciences 19 Beituchengxi Road, Chaoyang District, Beijing 100029, China
  • Q. LIU Paleomagnetism and Geochronology Laboratory, Institute of Geology and Geophysics, chinesse Academy of Sciences 19 Beituchengxi Road, Chaoyang District, Beijing 100029, China Function Laboratory for Marine Geology, National Oceanography Laboratory Qingdao 266061, China
  • T. ROMÁN-BERDIEL Dpto. ciencias de la Tierra. Universidad de Zaragoza. Área de Geodinámica Interna Pedro Cerbuna, 12, 50009 Zaragoza, Spain

Keywords:

Magnetite, Environmental magnetism, Añavieja Basin, Alluvial sequence, Vegetation cover, Temperature, NGRIP curve

Abstract

Environmental magnetic proxies were analyzed in a relatively monotonous, ~25.3m thick alluvial sedimentary sequence drilled in the Añavieja Basin (NE Spain). Results from the core AÑ2 suggest that the concentrationdependent magnetic parameters mainly reflect variations in the content of detrital magnetite, sourced in the catchment rocks and soils of the basin, via changes in the dynamics of alluvial fans due to temperature changes in the northern hemisphere during the Late Pleistocene. The correspondence between the magnetic proxies and the temperature variations in the North Atlantic region (NGRIP curve) indicates that higher (lower) concentrations and finer (coarser) magnetite grains coincide with warm (cold) periods. We propose that during cold periods, a sparser vegetation cover favored the incoming of higher energy runoff bearing coarser sediments to the basin that are relatively impoverished in magnetite. In contrast, during warm periods, the wider distribution of the vegetation cover associated with the lower runoff energy lead to finer, magnetite-richer sediment input to the basin. Maghemite, presumably of pedogenic origin, appears to be present also in the studied alluvial sediments. Further studies are necessary to unravel its palaeoclimatic significance.

Author Biography

A. MUÑOZ, Dpto. ciencias de la Tierra. Universidad de Zaragoza, Área de Estratigrafía Pedro Cerbuna, 12, 50009 Zaragoza, Spain

Area de Estratigrafia

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Published

2016-05-11

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Articles