Anthropogenic impact on sediment composition and geochemistry in vertical overbank profiles of river alluvium from Belgium and Luxembourg
Swennen, R.; Van der Sluys, J. (2002). Anthropogenic impact on sediment composition and geochemistry in vertical overbank profiles of river alluvium from Belgium and Luxembourg. J. Geochem. Explor. 75(1-3): 93-105. dx.doi.org/10.1016/S0375-6742(02)00199-1
In: Journal of geochemical exploration. ELSEVIER SCIENCE BV: Tokyo; New York; London; Amsterdam. ISSN 0375-6742; e-ISSN 1879-1689, meer
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| Author keywords |
heavy metals; pollution; overbank sediments; background concentrations; mineralisation; environmental assessment |
| Auteurs | | Top |
- Swennen, R., meer
- Van der Sluys, J.
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| Abstract |
The geochemical study of alluvial sediments allows to reconstruct pollution through time. Geochemical and sedimentological variations recorded in 40 vertical overbank sediment profiles from Belgium and Luxembourg can be classified in three dominant pattern types: . type 1 profiles with dominantly non-anthropogenically influenced geochemical distribution patterns. These profiles are devoid of anthropogenic particles such as charcoal, plastic, brick and slag fragments, with the exception, in some cases, of their uppermost parts. Background concentrations thus are displayed throughout the profile (subtype 1A). However, in this group, profiles displaying anomalous values caused by the presence of heavy minerals (subtype 1B) or by base metal mineralisations in the catchment (subtype 1C) also occur; . type 2 profiles displaying clear evidence of anthropogenic influences. Most of these profiles display a gradual increase in heavy metal content in their upper part, with values doubling or tripling (subtype 2A). However, other profiles display a dramatic increase in pollution-related elements caused by past or present-day heavy industrial activities in the catchment (subtype 2B). Here also the sedimentological logical patterns reflect the influence of the industrial activities; . type 3 profiles contain features related to pedogenetic translocations of mobile elements. Apart from classical pedogenetic features such as illuviation/eluviation, the mobility of As and Cd is of particular importance, From a sedimento logical point of view, these profiles do not necessarily differ from type I or 2 profiles. It should be noted that in some profiles, pattern types can be superimposed. Type 2B profiles are of particular environmental concern, because the potential release of heavy metals may have consequences for agricultural activities or groundwater contamination in the catchment. Furthermore, reworking of polluted sediments temporarily stored in the alluvial plain can also have negative effects on the ecosystem. |
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