- Startpagina tijdschrift
- Volume 94 (1971)
- Fascicule 3
- Distribution du cuivre dans les alluvions et les roches de la vallée de la Lomme (de Recogne à Grupont) : application de la théorie géochimique du bassin versant
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Distribution du cuivre dans les alluvions et les roches de la vallée de la Lomme (de Recogne à Grupont) : application de la théorie géochimique du bassin versant
Abstract
Stream sediment sampling and interpretation of regional geochemical survey data require consideration of the mechanisms of bedrock weathering, ionic trace element dispersion in chemical and colloidal solutions, and metal trace element fixation by ionic adsorption in soil and stream sediment.
Geochemical stream sediment theory takes account of thermodynamic laws which rule these mechanisms and demonstrates that the concentrations of trace elements are lognormally distributed. Application of this theory in the area of the Lomme valley in the Ardennes (Belgium), using stream sediment sampling near the point where each tributary enters the main stream, confirms that the copper trace element distribution is lognormal.
The copper lognormal distribution in stream sediment shows that:
1. Copper content in stream sediment is a good « tracer » for copper-rich bedrock.
2. Correlation between copper content in the stream sediments and that in outcropping Cambrian and Lower Devonian formations clearly shows the influence of regional bedrock geology on stream sediment geochemistry.
3. Measurements of « background » concentrations for transition metals in the stream sediments provide a simple method for controlling metallic pollution in the river water.