Soils, geomorphology, landscape evolution, and land use in the Virginia Piedmont and Blue Ridge

Abstract

The object of this fi eld trip is to examine the geology, landforms, soils, and land use in the eastern Blue Ridge and western Piedmont geologic provinces in Orange County in central Virginia. A complex mix of igneous, sedimentary, and metamorphic bedrocks, ranging in age from Mesoproterozoic to Triassic (possibly some Jurassic) underlie the area. Soils are equally varied with a total of 62 series mapped in Orange County alone. The area being relatively stable tectonically, landforms generally refl ect the resistance to weathering of the bedrock. Area landforms range from a low ridge over Catoctin greenstone to a gently rolling Triassic basin. Soils examined on the trip represent three orders: Ultisols, Alfi sols, and Inceptisols. Residual soils clearly refl ect the compositions of the parent rocks and saprolites are common. Map patterns of forested versus nonforested lands bear a striking resemblance to the distribution patterns of the different soil and bedrock types. Our work has shown that the vast majority of the land in central Virginia, even that forested today, shows evidence of past clearing and cultivation. However, the harsh demands of growing tobacco wore out the less fertile and more erodible soils by the mid-nineteenth century resulting in their abandonment and the subsequent regeneration of the vast tracts of hardwood forests we see today. Only the most productive soils remain in agriculture.

Modeling the Spatial Dynamics of Soil Organic Carbon Using Remotely-Sensed Predictors in Fuzhou City, China

“…In general, landform variations may contribute to changes in soil properties (clay content), human activities (i.e., land use), vegetation quality and quantity, and alteration of climatic variables (temperature and precipitations), which may affect the SOC distribution. Similarly, a previous study reported that landform elements play a significant role in the variability of SOC [77]. Even though the variability of SOC depends on geologic, climatic, topographic, vegetation, and land-use variables, landform plays a crucial role in modifying all these factors.…”

Modeling Soil Organic Carbon Using Remotely-Sensed Predictors: A Case Study from Fuzhou City, China

“…In general, the landform variations may contribute to changes in soil properties (clay content), human activities (i.e., land-use), and vegetation quality and quantity, alteration of climatic variables (temperature and precipitations) that may affect the SOC distribution. Similarly, previous studies reported that landform elements play a significant role in the variability of SOC [69,70]. Even though the variability of SOC depends on geologic and climatic, topographic, vegetation [32], and land-use variables [71], landform plays a crucial role in modifying all these factors [72].…”

Low Vp/Vs Values as an Indicator for Fractures in the Critical Zone

“…We investigated two sites on crystalline bedrock (Figure 1). The South Carolina Piedmont (SCP) site (436432E 3829851N Z17N) is in the Appalachian Piedmont and is underlain by igneous and metamorphic rocks (Pavich, 1989; Secor et al., 1986; Sherwood et al., 2010). The Blair Wallis (BW) site (327659E 3847004N Z13N) is on granitic rocks of the Sherman batholith, which has little to no foliation (Edwards & Frost, 2000; Eggler et al., 1969; Frost et al., 1999).…”