Geochemistry of the Detroit River Sediments

Abstract

The objectives of the investigation were to provide information on the concentration and distribution of metals in bottom sediments of the Detroit River and to study the association of metals with various sediment components. Concentrations of major elements (Si, Al, Ca, Mg, Na, K, Fe, Mn, and P) and metals (Co, Cr, Cu, Ni, Pb, and Zn), particle size distribution, and mineralogical composition were determined in 20 surficial sediment samples collected along the Detroit River in 1983. Significantly higher concentrations of metals in the Detroit River sediments than those reported in Lake St. Clair and Lake Erie sediments indicated input from sources in the river's drainage basin. Poor relationships exist between the metals and organic C and the metals and the silt-clay size fraction (< 63 μm). The association of metals with sediment particles was investigated by a separation of sediment into seven size fractions ranging from < 13 to > 63 μm. Zn, Ni, Cr, and Pb were accumulated in the < 13 μm size fraction. However, Cu and Cr concentrations were highest in the < 13 and 48 to 63 μm fractions. Quartz, feldspars, and calcite were found in the > 63 μm fraction. Dolomite, feldspars, and quartz were in the 13 to 63 μm fraction and the clay minerals illite, chlorite, and kaolinite were in the < 13 μm fraction. Concentrations and relationships among major elements reflected the mineralogical composition of different particle size fractions.