HR: 0800h
AN: GP31B-0842    [Abstracts]
TI: Magnetic Measurements as Indicators of Soil Development in a Chronosequence in Southeast Spain
AU: Foster, G C
EM: gcf@aber.ac.uk
AF: Institute of Geography and Earth Sciences, University of Wales Aberystwyth, Aberystwyth, SY23 3BD United Kingdom
AU: * Hannam, J A
EM: hannam@liverpool.ac.uk
AF: Department of Geography, University of Liverpool, Liverpool, L69 7ZT United Kingdom
AU: Harvey, A M
EM: amharvey@liverpool.ac.uk
AF: Department of Geography, University of Liverpool, Liverpool, L69 7ZT United Kingdom
AB: Soil profiles on a sequence of Quaternary river terraces in southeast Spain show age-related characteristics of colour and carbonate accumulation indicative of long-term soil development. The terraces exhibit similar relief and parent material that provide a unique soil sequence differentiated primarily by time and secondarily by climate. Magnetic measurements of relic soils show evidence for the pedogenic development of secondary magnetic minerals in association with the modification of the detrital signal from the fluvial gravels. Although time is a major contributor to soil development and magnetic characteristics, climate is likely to have affected pedogenic and magnetic mineral development in this region over the late Quaternary. Magnetic measurements highlight a threshold in the maximum concentration of neoformed superparamagnetic minerals, likely to be determined by climate regime and the longevity of soil development. The magnetic signature is deconvoluted into a dominant signal derived from primary minerals and their pedogenic alteration and a secondary neoformed viscous component. The investigation of complex magnetic signatures facilitates the proposal of a conceptual model of late Quaternary soil development in this region.
DE: 1512 Environmental magnetism
DE: 1540 Rock and mineral magnetism
DE: 1625 Geomorphology and weathering (1824, 1886)
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting