Stream sediment geochemistry remains a versatile tool in exploration especially in regionswhere knowledge of the primary mineralization is lacking and the exploration activities are still at reconnaissance stage. In this study, we investigate the concentrations of gold and associated elements in stream sediment samples from the Vaimba-Lidi drainage system in northern Cameroon; a relatively remote area where alluvial gold is worked locally, and exploration activities are at early stage. The main river and its principal first and second order tributaries were sampled, panned for gold grain recovery and the 100 μm size fraction analyzed for Au by fire assay with Ni finish. A suite of other elements were analyzed for by inductively coupled plasma mass spectrometry (ICP-MS). Gold grades estimated by the panning and weighing technique rarely exceed 1 g/t while the Au concentrations from chemical analysis range from 3.0 to 354.0 ppm. The spatial distribution of gold and all the other elements are presented as point symbol maps and the data analyzed using multivariate statistics. From the principal component analysis (PCA), the As-Mo-W-Ag as well as the Au-Zn factors point to the presence of primary hydrothermal gold-sulphide mineralization in the area and this can be further investigated. These results highlight the importance of multielement analysis and multivariate statistical interpretation of sediment geochemical data in inferring the nature of the underlying primary mineralization in any region.No represents the number of samples with concentrations above their detection limit used to calculated the statistics, Min, Max, Std. D represents the Minimum, Maximum concentration value and standard diversion, respecively, / represents no value. t

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Abstract. The modelling of leaching of nitrate and other solutes in artificially drained soils is complicated by the need to consider both unsaturated and saturated components of the system. This work is an attempt to couple together an unsaturated zone transport model (Addiscott & Whitmore, 1991) with a steady state travel‐ time model (Ernst, 1973) for the saturated zone. The model was tested using chloride leaching data from eight hydrologically isolated plots on a pipe‐drained clay loam soil. Approaches to parameter estimation are discussed. Results were variable, for on some plots saturated zone travel time could be virtually neglected, whereas on other plots this component was apparently important.

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