The Virginia Division of Mineral Resources and the Virginia Institute of Marine Science jointly made three cruises over the Virginia continental shelf in April and July of 1985 to sample known heavy-mineral sites for minerals of potential economic and/or strategic value. In addition to sampling, side-scan sonar and sub-bottom profiling surveys were performed at a site off Smith Island. At the Smith Island site, as many as four acoustic horizons were detected within the upper 6 meters of sediment. The uppermost seismostratigraphic layer consists of fine and very fine sand and contains the higher concentrations of heavy minerals. There are also higher concentrations of heavy minerals on the flanks of topographic ridges. The average content of heavy minerals for all samples collected is 8 percent by weight
