caa a22 4500 469077654 CHVBK 20180323132939.0 cr unu---uuuuu 170328e19920101xx s 000 0 eng 10.1007/BF00181713 doi (NATIONALLICENCE)springer-10.1007/BF00181713 Storage diagenesis versus sulphide authigenesis: possible implications in environmental magnetism [Elektronische Daten] [F. Oldfield, I. Darnley, G. Yates, D. France, J. Hilton] Experiments involving the gradual drying out of controlled mixtures of soil and organic lake sediment during storage at room temperature show that this leads to a loss of magnetic susceptibility and isothermal remanence greatly in excess of the initial values for the sediment components of the mixtures. We conclude that during storage in the moist state, soil-derived, fine-grained, ferrimagnetic iron oxides (magnetite and/or maghemite) are transformed to paramagnetic and/or imperfect antiferrimagnetic minerals. The imperfect anti-ferromagnetic component of the initial mixtures, which probably includes goethite, appears to survive and may even increase during storage. The experimental results compare well with the previously documented effects of storing wet sediment from the site, Peckforton Mere, Cheshire, U.K., over a comparable time interval. We conclude that transformation of fine grained ferrimagnets during ‘storage diagenesis' may be responsible for many of the examples of loss of magnetic susceptibility and remanence attributed by other authors solely to the oxidation of an iron sulphide such as greigite. Only where greigite is positively identified is it valid to infer a contribution from it to the magnetic properties of lake sediments: loss of susceptibility or remanence during storage is not alone a sufficient basis for such an inference. Early drying of samples will normally avoid the effects of storage diagenesis; and recent sediment samples so treated will, where greigite formation, bacterial magnetite and magnetite dissolution are insignificant, provide a valid basis for source identification on the basis of magnetic properties. Kluwer Academic Publishers, 1992 environmental magnetism nationallicence lake sediments nationallicence diagenesis nationallicence sulphides nationallicence sample storage nationallicence Oldfield F. Department of Geography, University of Liverpool, L69 3BX, Liverpool, UK aut Darnley I. 12, Woburn Drive, Lodgefield Park, Halesowen, W. Midlands, UK aut Yates G. 42 Kent Road, Formby, L37 6BQ, Liverpool, UK aut France D. Department of Geography, University of Liverpool, L69 3BX, Liverpool, UK aut Hilton J. Institute of Freshwater Ecology, Ferry House, Windermere, UK aut Journal of Paleolimnology Kluwer Academic Publishers 7/3(1992-01-01), 179-189 0921-2728 7:3<179 1992 7 10933 https://doi.org/10.1007/BF00181713 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00181713 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Oldfield F. Department of Geography, University of Liverpool, L69 3BX, Liverpool, UK aut NATIONALLICENCE 700 1- Darnley I. 12, Woburn Drive, Lodgefield Park, Halesowen, W. Midlands, UK aut NATIONALLICENCE 700 1- Yates G. 42 Kent Road, Formby, L37 6BQ, Liverpool, UK aut NATIONALLICENCE 700 1- France D. Department of Geography, University of Liverpool, L69 3BX, Liverpool, UK aut NATIONALLICENCE 700 1- Hilton J. Institute of Freshwater Ecology, Ferry House, Windermere, UK aut NATIONALLICENCE 773 0- Journal of Paleolimnology Kluwer Academic Publishers 7/3(1992-01-01), 179-189 0921-2728 7:3<179 1992 7 10933 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer