Environmental magnetism as a dating proxy for recent overbank
sediments of (peri-)industrial regions in the Czech Republic and UK

Chudaničová, M; Hutchinson, SM; Hradecký, J; Sedláček, J

Abstract

Twenty five floodplain sediment profiles from seven rivers in eastern Czech Republic and three in north west
England were collected to examine the hypothesis that magnetic enhancement in recent sediments is predominantly
of anthropogenic origin and that magnetic parameters can be used as a dating proxy reflecting changes in intensity of industry sources over time. Natural sources of magnetic enhancement were excluded and anthropogenic enhancement was identified as exhibiting elevated values of χlf, ARM, SIRM, SIRM/χ and S-ratios with lowvalues of χfd%. Magnetic spherules, typically formed through fossil fuel combustion processes, were observed by scanning electron microscopy (SEM) in these sediments. To assess the potential of magnetic parameters as a chronometer, the approach was compared with frequently used dating techniques: concentrations of heavy metals and 137Cs.The floodplain profileswere divided to three groups according to the characteristics of their trends with depth in
magnetic parameters; χlf in particular, and the suitability of magnetic properties as a dating proxy. Group 1,
which included the majority of the profiles, exhibited magnetic enhancement in the upper part of its profiles
and a single maximum in χlf. This group exhibited a clear suitability for our proposed ‘magnetic dating’ as the
magnetic record reflected the industrial history of the region and was aligned with the chronologies of
the other dating techniques. Profiles magnetically enhanced throughout their depth and lacking any clear
trend comprised group 2; here a mineral magnetic approach to dating was limited as the magnetic signal was
diluted by a high sedimentation rate or impacted by local anthropogenic factors. All profiles from England
were included in group 3 because their magnetic depth profiles were influenced by natural sources of magnetic
particles or specific sedimentary conditions, and a longer industrial history and thus needed an individual
interpretation. However, they still reflected the regional deposition history of industrial sources of ferrimagnetic
particles. Overall, magnetic parameters proved to be an efficient dating proxy with potential for recently
aggrading rivers

Citation

sediments of (peri-)industrial regions in the Czech Republic and UK. CATENA, 142, 21-35. https://doi.org/10.1016/j.catena.2016.02.008

• Journal Article Type: Article
• Acceptance Date: Feb 8, 2016
• Online Publication Date: Feb 20, 2016
• Publication Date: Feb 20, 2016
• Deposit Date: Mar 9, 2016
• Journal: CATENA
• Print ISSN: 0341-8162
• Publisher: Elsevier
• Volume: 142
• Pages: 21-35
• DOI: https://doi.org/10.1016/j.catena.2016.02.008
• Publisher URL: http://dx.doi.org/10.1016/j.catena.2016.02.008
• Related Public URLs: http://www.journals.elsevier.com/catena/
• Additional Information: Funders : University of Ostrava; Grant Number: SGS18/PřF/2015–2016