Genesis and Morphology of the Red Soils in the Southeastern United States

The region of red soils in the southeastern United States is confined very largely to the southern Piedmont belt with adjoining areas of limestone valleys and uplands, and coastal plains. According to Marbut (11) lt extends from Virginia through the Carolinas, Georgia, Alabama and part of Mississippi, with part of South Georgia and Florida comprising the zone of semi-lateritic soils. The soils in this belt have developed through the weathering of a variety of rocks under a mixed forest condition and a warm temperate climate with an annual precipitation of 50 to 60 inches, and a mean annual temperature of about 60 degrees F. Under such conditions the soil processes are active and the environment is unfavorable for the accumulation of very much organic matter in the soil. The climatic forces favor active leaching during the greater part of the year by reason of the fact that the soils are frozen only a short period, if any. This downward movement of soil water has removed the carbonates and other soluble salts, as well as soil particles, from the A horizon. Some of these are deposited in the B horizon. The soils in this region as a group represent an Intermediate stage of development between the gray forest soils to the north and the lateritic soils to the south. Due to the irregular topography, the soils in this region are subject to e o ionerosion espec al-