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In an area east of Leuven (central Belgium), a buried sandy estuarine deposit of Oligocene age contains a dark colored organic layer of about 4 m thick. Our results suggests that the organic matter is an illuvial horizon, therefore warranting the hypothesis that the layer may qualify for a giant buried spodic horizon rather than a remainder of a Tertiary oil seepage as suggested by Van Riessen and Vandenberghe (1996). Of particular importance is the micro-morphological evidence, which reveals that the mainly monomorphous organic matter is present as ubiquitous coatings and concentrations around the quartz grains. These coatings show the for Podzols very typical polygonal cracked patterns. The geochemical signature (stable carbon isotope analysis) also gives strong indications for a continental origin of the organic carbon and therefore support the pedogenetic origin of the horizon. The paleopedological scene into which this soil has developed is inferred from the data.

<p>Older landfills are notorious for being vague black boxes. The amount, type and location of the dumped material was rarely or inaccurately recorded. This lack of information can be a problem during redevelopment projects, remining projects and risk assessments for the landfill. To decrease the analytical and spatial uncertainties in the conceptual model of the landfill during these investigations, we need accurate sampling and analysis methods but also sufficient amount of data. A High Resolution Site Characterisation (HRSC) approach is based on measurements and data density that are in the same order of heterogeneity of the site. This approach, that we apply on a daily base in soil contamination projects, was applied in collaboration with Witteveen+Bos on a former landfill site in Flanders. In this project an Optical Image Probe (OIP) combined with Electrical Conductivity (EC) measurements was used with a direct push rig. Using this probe, at a rate of 1 frame each 1.5cm, the subsoil layers were explored with a visual light camera integrated in the probe. The data were studied and compared to landfill trenches to identify the layers. It could be concluded that the probing’s were a good supplement to the trench data. This because of the speed of data acquisition, the less intrusive character and reduced Health and Safety concerns for workers and surrounding.</p>