The Delassus series consists of deep and very deep, moderately well drained soils with fragipans formed in loess mixed with slope alluvium and the underlying slope alluvium or residuum from granite and similar rocks of igneous origin.
Permeability is moderate in the upper part and very slow in the fragipan.
These soils are on wide gently and moderately sloping uplands with slopes ranging from 2 to 15 percent. Mean annual temperature is 56 degrees F, and mean annual precipitation is 42 inches. Delassus silt loam - on a north facing convex slope of 3 percent under mixed hardwoods at 975 feet elevation. 37 degrees 40 minutes 57 seconds N. and long. These are the Annandale , Beltsville , Califon , Hanover , Meckesville , Monongahela , Tonti , Trego , and Watson series.