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Soil genesis studies of upland soils formed in transported materials overlying the Virginia Piedmont using trend-surface analysesSaxton, H. Thomas 10 January 2009 (has links)
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
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