sequential partial extractions show that partitioning of uranium, copper, zinc, iron and manganese into lake, stream and bog sediments are affected by the type and abundance of component fractions present in sediments and by the physico-chemical conditions of the superjacent waters. the water ph influences the concentration of uranium retained by organic matter as well as the relative proportion partitioned into the amorphous iron hydroxide fraction and the humic and fulvic acid components of the organic matter fraction. copper partitioning is controlled by the percent carbon content of sediments which influences the concentration of metal retained in the organic matter fraction. the amount of copper retained by other component fractions is determined by their relative abundance in sediments. the eh-ph conditions of the superjacent waters control the solubilities of iron, manganese and zinc thereby affecting the availability and sorption of these metals into the organic matter and inorganic hydroxide fractions of sediment. metal partitioning characteristics and physico-chemical factors which influence metal partitioning should be considered when using lake, stream and bog sediments in geochemical exploration.