Tuesday, November 6, 2007
199-4

Morphological and Hydrological Correlations of Mafic Landscapes in the Piedmont of Georgia.

Kelli Coleman, Larry West, and J. Frank Newsome. 3111 Miller Plant Sciences Bldg, University of Georgia, University of Georgia, Dept. of Crop & Soil Sciences, Athens, GA 30605-7272

While most soils in the Piedmont of Georgia have formed from saprolite from felsic gneiss or schist, approximately 10% of the soils have formed from saprolite of mafic and ultramafic rocks. Soils developed from these two contrasting parent materials have differing physical and chemical characteristics, thus making their spatial distribution of these soil types a critical factor when examining the interaction between soil and water. This study was conducted on a 40 ha pasture near Eatonton, GA where variable thickness of loamy felsic material caps underlying soil horizons developed from underlying chlorite schist. The objectives were to evaluate depth and distribution of loamy-textured parent material cap over the site, and to evaluate the effect of the lithologic discontinuity on seasonal water tables. Undisturbed core samples were taken to determine the depth to the lithologic discontinuity and evaluate the abundance and type of redoximorphic features. A digital elevation model was created for the site with a CR344 Leica GPS unit, and seasonal water tables were evaluated by weekly piezometer readings. Collectively, hillslope position was highly related to thickness of the loamy parent material capping. Perched water was also observed on the residual parent material, although the depth to perched water may not be related to the current ground surface.