The influence of parent materials upon the formation and morphology of some soils of the Highland Rim and Brotherton Bench in Putnam County, Tennessee

On the Highland Rim and at a higher elevation on the Brotherton Bench in Putnam County, Tennessee are certain soils which have sola that. are very similar, even though their substrata are variable. Each has a discontinuity in its profile at a depth of about 24 to 30 inches. The mantle thickness is greatest on smooth topography and diminishes rapidly with increased steepness. These observations make the soils appear to have formed, at least in part, from a deposit of transported parent material. The relationship of mantle thickness to topography at site 2 is shown in Figure 1. All of the sites have topography similar to this.

The physiography of the Highland Rim and Brotherton Bench along with the rest of the County is shown in Figure 2. The soils investigated in this study have tentatively been correlated Holston silt loam on the Brotherton Bench and Mountview silt loam on the Highland Rim.

The remarkable similarity and uncertain genesis of the upper parts of the profiles need explanation before the soils can be thoroughly understood and accurately classified. The objectives of this investigation were to determine the nature and origin of the parent material from which the upper horizons of these soils were formed and to compare properties of Mountview silt loam and Holston silt loam.