ABSTRACT

A study of the variation in distribution of heavy minerals in stream bed sands of some tributaries of the South River, Augusta County, Virginia, was planned according to a nested sampling design so that the results of grain counts could be examined by the analysis of variance. The sampling design provided data for comparing heavy-mineral content on the two sides of the main stream, in five tributaries on each side, in four sampling localities in each tributary, and in three counts on each heavy-mineral slide. The study showed that both ilmenite and zircon differed significantly percentage-wise between the tributaries within a side, and when the data were expressed as weight in grams, these also differed significantly between the sides.

The heavy minerals were derived from sedimentary rocks of Early Cambrian to Early Ordovician age, with one tributary obtaining minerals from Precambrian(?) rocks. The mineral assemblages have few species, as is common in sandstones and limestones. Opaques (largely ilmenite), zircon, tourmaline, rutile, and epidote are the most abundant minerals. The study was restricted to the grains in the 0.12-to 0.06-mm grade (-120 +230 mesh U. S. Standard Sieves).