A sequential extraction scheme is utilized to determine the geochemical partitioning of Cu, Zn and Pb among hydrous Mn- and Fe-oxides, organics and residual crystalline silicates and oxides in the minus-80-mesh (< 0.18 mm) sediments and in boulder coatings from a stream in Lincoln County, Georgia (U.S.A.). The stream drains an area containing a CuZnPb-sulfide deposit (Magruder Mine). The boulder coatings contain mainly Mn-oxides and organics, with minor hydrous Fe-oxides. In the sediment, the chemically active phases are mainly hydrous Fe-oxides and organics, probably because Mn is leaching out of the sediments and precipitating on the exposed surfaces of boulders. In the boulder coatings, competition among Fe- and Mn-oxides and organics for Cu, Zn and Pb follows the order: Cu, organics > Fe-oxides > Mn-oxides; Zn, Mn-oxides {reversed tilde equals} organics > Fe-oxides; Pb, Fe-oxides > organics > Mn-oxides. In the sediments, organics are the most efficient scavengers of all three ore metals. These results emphasize the importance of organics as sinks for the ore metals, even in environments with high concentrations of Mn- and Fe-oxides. Of the ore metals, Zn appears to be the most mobile, and is partitioned most strongly into the coatings. However, anomaly contrast for hydromorphic Zn, normalized to the MnFe-oxide or organic content, is similar in sediments and coatings. Cu shows the highest anomaly on the boulder coatings, probably due to precipitation of a secondary Cu mineral. In contrast, detrital Pb in the pan concentrates shows a better anomaly than any hydromorphic Pb component. ?? 1981.