The accumulation of copper, lead, zinc, nickel, and silver in lake sediments from the Clam Lake and Monico regions has been studied to provide information on the potential for anomalous mineralization in the underlying Precambrian bedrock. The high organic content of the lakes suggests that the metals in part were fixed within the sediments by adsorption onto organic debris.

A positive linear relationship exists between the mean metal contents of Cu, Pb, Zn, and Ni and the mean weight percent organic matter in the lakes, when the data are plotted on semilog paper. The relationship is most clearly demonstrated by lead and nickel. Confidence limits were calculated for the regression of Cu, Pb, Zn, and Ni upon organic matter, and data points falling above the upper limits may represent anomalous metal concentrations within the lake sediments.

The northern part of the Clam Lake region, and the area around Monico in the Monico region, are of greatest interest with regard to possible mineralization in the Precambrian bedrock. In the Clam Lake region, at the 95% level of confidence, Beaver, Tea, Coffee, Mineral, Potter, and Buffalo lakes exhibit anomalous concentrations of one or more of Cu, Pb, Zn, and Ni. The same is true for Ogemaga, Sequilla, Kechewaishke, and Tank lakes in the Monico region. At the 99% level, significant metal concentrations in the Clam Lake region occur in Beaver, Tea, Coffee, and Potter lakes; and in the Monico region, in Ogemaga, Kechewaishke, and Tank lakes. Generalizations with respect to silver are difficult because of the low concentrations and the spotty nature of the data. Additional work should be done to more clearly define the potential for anomalous mineralization in the Precambrian rocks of the two regions.