Aragon soils have Bt horizons that are mottled in the upper part. Aragon and Nectar soils formed in weathered limestone, sandstone, shale, or siltstone. Chestatee soils have more than 15 percent by volume of coarse fragments throughout. Darley soils contain layers of fractured ironstone in the B horizon. Herndon soils have Bt horizons with hue of 5YR or yellower.
Spotsylvania soils have a lithologic discontinuity.
Mahan soils formed in coastal plain sediments and have coarse fragments of ironstone. Georgeville soils are on gently sloping to moderately steep Piedmont uplands. Slopes are generally 6 to 12 percent and range from 2 to 30 percent. The soil formed in residuum weathered from fine-grained metavolcanic rocks. Mean annual precipitation ranges from 37 to 60 inches, mean annual temperature ranges from 59 to 66 degrees F, and the frost-free season ranges from 190 to 240 days.