Local concentrations of gold have been identified in surface sediments on the continental shelf off southern Oregon between Cape Arago and Cape Sebastian, a
distance of about 40 miles. Concentrations of gold range from the lower limit of detection, 5 parts per billion, to almost 150 parts per billion. The largest gold
anomaly is an area of 15 to 20 square miles off Cape Blanco. Gold is associated with black sands believed to be relict beach placers formed during a previous low
stand of the sea. Although the gold content is low, it may indicate higher grade material at depth; drilling will be necessary to determine the economic potential of the placers.