Cadmium distribution in soils covering Jurassic oolitic limestone with high Cd contents in the Swiss Jura
Détails
ID Serval
serval:BIB_2843D4DD0023
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Cadmium distribution in soils covering Jurassic oolitic limestone with high Cd contents in the Swiss Jura
Périodique
Geoderma
ISSN-L
0016-7061
Statut éditorial
Publié
Date de publication
2009
Peer-reviewed
Oui
Volume
150
Pages
287-301
Langue
anglais
Résumé
Oolitic carbonates belonging to the Hauptrogenstein Formation of Bajocian (Middle Jurassic) age have been shown to be anomalously enriched in cadmium (Cd) throughout the Jura Mountains. Soils associated with this type of rock substratum may be naturally polluted with regards to Cd. At Schleifenberg (Canton Basel Land, Switzerland) the Hauptrogenstein Formation is almost entirely exposed along a trail on its SW flank. Cadmium concentrations were systematically measured throughout this formation and Cd enrichments in rocks are shown to occur to a maximum content of 4.9 mg kg(-1). We investigated associated soils, which cover the entire outcrop, and show that they have been formed through the weathering of the underlying bedrock and through the uptake of colluvial limestone fragments from the same and older formations. Cadmium contents in the soils reach a maximum value of 2.0 mg kg(-1), thereby exceeding the official Swiss indicative guideline value for soils fixed at 0.8 mg.kg(-1). Mineralogical analyses on the soils and associated bedrock suggest that no allochthonous component related to aeolian transport is present. Sequential extractions applied to selected soil samples show that about half of the Cd resides in the carbonate fraction coming from the fractured parent-rock, while the Cd released from the weathered carbonates is associated either with organic matter (over 10%) or with Fe and Mn-oxihydroxides (approximately 30%). No exchangeable Cd phase was found and this, together with the buffer capacity of this calcareous soil, suggests that the amount of mobile Cd is quite negligible in this soil, which also greatly reduces the amount of bioavailable
Mots-clé
Anomalous enrichments, Cadmium, Geogenic, Natural pollution, Oolitic carbonates, Soil, Speciation
Création de la notice
04/05/2009 13:57
Dernière modification de la notice
20/08/2019 13:07