No abstract

Soils on two stream terrace levels along the Tennessee River, south of Knoxville, TN, were studied to evaluate genesis of stream terrace soils representative of the Southern Appalachian Ridge and Valley major land resource area. The soils on the lower terrace were described and sampled to a depth of about 12 ft, and on the upper one to about 17 ft. Iron oxides, Mn oxides and particle size variation with depth indicate that these soils formed during several periods of deposition. The older (upper) terrace soil had a well‐developed argillic horizon, moderate structure, up to 50% clay and appreciable free Fe oxide content. The soil on the lower terrace did not have well‐developed morphology, indicating it to be considerably younger than the upper terrace soil. Physical and chemical properties of the paleosol horizons showed that varying periods of weathering and soil development occurred following each episode of deposition. Clay illuviation and accumulation of Fe were good indicators of soil development in the paleosols. Sand distribution was a useful indicator of the depositional stratigraphy.

Organic soils have been observed occasionally by soil surveyors in the Tennessee Blue Ridge, but most were not large enough to delineate as separate map units. An area of dysic, Lithic Borofolists was mapped in the Cherokee National Forest in Greene County, at elevations around 4,400 ft. The mapping unit was named Borofolist‐rock outcrop complex, 20 to 50% slopes, windswept, and occurred in a frigid area along the crest of the Bald Mountains. These soils ranged from less than 10 to about 30 in. deep, and consisted of extremely acid fibric, hemic, and sapric materials overlying massive quartzite bedrock. Mineral soil horizons occurred in the lower parts of some profiles. The parent material was litter from rhododendron, mountain laurel, various ferns, mosses, and under‐story plants. Although of small extent, this is an interesting ecosystem composed of fragile soils that could be destroyed if disturbed significantly.

No abstract

A simple and rapid method for determining the mineralogical classification of soils with loamy and sandy particle‐size families is proposed. The procedure involves the use of differential staining techniques to separate potassium and plagioclase feldspars from quartz and other minerals. The use of a micro video zoom optics system reduced the tedium commonly associated with petrographic microscope analyses. Compositional information collected by grain count analysis can be augmented with x‐ray powder diffraction data. The procedure outlined was developed to provide the data necessary to classify the mineralogy of the soils investigated.