The London-Virginia Mine in Buckingham County is one of several abandoned gold mines that are scattered throughout the polydeformed metavolcanic and metasedimentary rocks of the Virginia Piedmont. Production began at the London-Virginia in 1853 and continued intermittantly through 1939. Gold mineralization (averaging 1.2 ppm but with localized concentrations of up to 14.1 ppm) occurs within a ferruginous quartzite lens and a muscovitic schist contained in the Cambrian Chopawamsic Formation. The deposit consists of a series of conformable stratigraphic units which include, from bottom to top: 1) a garnetiferous chlorite schist 2) a magnetite schist 3) a quartz-muscovite schist 4) a ferruginous quartzite and 5) a chlorite-biotite schist. These lithologies represent periods of submarine volcanism (units 1 and 5) and volcaniclastic sedimentation (unit 3) with intervening episodes of hydrothermal exhalative activity (units 2 and 4). The mineralogic assemblages characteristic of the exhalative units suggest that the premetamorphic sediments were rich in hydrothermal silica, goethite, amounts of barite, gold. The deposit limonite, and pyrite with minor calcite, base metal sulfides and is believed to have formed as a result of exhalative processes analogous to those currently active in the Atlantis II Deep of the Red Sea. Silica-rich, hypersaline brines discharging through fractures in the sea floor ponded in a local basin. The episodic influx of volcaniclastic debris and extensive deposition of hydrothermal silica diluted the concentration of sulfides and gold to produce a low-grade, siliceous mineralized zone. The local exhalative event was terminated when the basin was capped by a volcanic flow. / M.S.

Soils overlying residuum on upland divides and interfluves that formed from transported material are common in the Virginia Piedmont. They are thought to occur on the oldest landscapes in the region. A study was initiated in Appomattox County and a small portion of Buckingham County encompassing an area of 238 square miles. The origin, age and characterization of these soils is studied. Mapping units comprised of red subsoil components and mapping units with non-red subsoil components are compared. Trend-surface analysis of the elevations at which they occur and chemical and physical data from twenty-four pedons in Appomattox County are used. The mapping units contain a complex mixture of taxonomic classifications that encompass pedons with and without palic clay distributions. Wetness due to perched water tables at variable depths also affects classifications. The red subsoil mapping units tend to occupy the older landscapes. Age estimates are derived from a comparison of trend-surface elevations between the transported soils and the present-day surface. These comparisons result in age estimates of 0.8 million years to 6.25 million years BP. Therefore, the oldest geomorphic surfaces in the south central Piedmont of Virginia may be estimated as late Pliocene to Miocene age landscapes. These soil materials were deposited through a process of landscape inversion dominated by subsidence and colluviation. / Master of Science