All real property in Virginia, including mineral land, improvements thereon, and minerals, is reserved for localities as a source of tax revenue. The ad valorem taxation of mineral property has traditionally been a responsibility of county commissioners of the revenue. Because of the technical nature of mineral property assessment and the lack of expert assistance available to commissioners of the revenue, there arises a question as to the equity with which mineral property is taxed. Since coal is Virginia's most extensive mineral resource, the study was confined to the ad valorem taxation of coal property. It was found that often economic factors such as thickness of the seem, quality of the coal, and location of the deposit are not considered by commissioners of the revenue in evaluating coal property. Investigations made in the large coal-producing counties revealed wide variations in assessment procedures, involving heavy reliance on information obtained from the owners of coal deposits. This indicates the probable existence of inequalities in the assessment of mineral property. A comparison of assessed valuation and the taxes levied thereon with the value of mineral production further indicates the existence of inequalities. It was found that the taxes levied on all mineral property, and the taxes levied on mineral property under development only, amounted to 0.L and 0.1 percent, respectively, of the value of mineral production. Also indicated, but not conclusively, was a lower ratio of assessed to actual value for coal property than for ordinary real property. A majority of the commissioners of the revenue interviewed felt that improvements needed to be made in assessment procedures in order to bring about a more equitable ad valorem taxation of mineral property. Assistance similar to that provided counties in the assessment of ordinary real property by the State Department of Taxation would seem a logical solution to the problem of attaining accurate mineral property assessment data. Such assistance might be properly provided by the Virginia Geological Survey. The provision of assistance in determining the extent and value of mineral property would overcome the basic difficulty associated with the ad valorem taxation of such property. / Master of Science

X-ray diffraction studies of 29 Virginia Blue Ridge and Piedmont soil profiles and petrographic examinations of the parent rocks reveal that even after prolonged chemical weathering, physical and mineralogical differences exist between soil types which are due largely to changes in the parent rock, and to a lesser extent changes in the topography. Soils developed from different source rocks can be distinguished on the basis of color, texture, degree of contrast between horizons, and depth to fresh rock. The clay minerals of such soils differ in their distribution, amount and kind. The role of parent material in soil and clay mineral formation is a complex function of several variables: (1) chemical composition (2) mineralogical composition (3) rock texture and (4) rock structure. Soils developed from calcium-aluminum rich rocks or from basic rocks which have structures or textures not conducive to good drainage are characterized by kaolin and montmorillonite clay minerals and by dense plastic, poorly drained, clayey subsoils. In all other soils and in the surface horizon of these soils, the major clay minerals are kaolin and vermiculite. Topography affects the degree of profile development, color, and soil texture and controls the rate of clay mineral accumulation and weathering. The climates of the Blue Ridge and Piedmont are most favorable to the formation of kaolin minerals. However, greater amounts of kaolinite appear to be formed in the warmer Piedmont climate and more vermiculite in the cooler Blue Ridge climate. The most important mechanism for clay mineral formation is probably by direct alteration of the primarily silicate minerals. The distribution of these clays in the profile is determined by the weathering stability of the primary silicate. All ferromagnesium silicates weather to 14 A clay minerals. An intermediate 14 A chlorite phase was not observed. The most common product is vermiculite. The formation of montmorillonite is controlled by the four parent material factors listed above. Hornblende and augite are the chief source materials of montmorillonite. Biotite possibly weathers to montmorillonite if the internal drainage is strongly retarded. Montmorillonite weathers to vermiculite in the surface horizons. Kaolinite forms early in the profile during the weathering of feldspar. Medium- to coarse-grained muscovite is also a source of kaolinite. There was no evidence found to indicate that kaolinite is a weathering product of the 12 A clay minerals. Illite occurs in minor amounts in a few micaceous profiles but appears to be the result of mechanical break-down of larger mica particles. / Master of Science

A heavy mineral mining company (RGC Inc.) faces challenging mining and reclamation practices for its proposed operation in the Upper Coastal Plain of Virginia due to the high clay content of the deposit. The original intent of this study was to identify the mineralogy present in the proposed mining area and to determine similarities and differences among sampled pedons. Twenty-eight typical pedons were sampled throughout the profile and these samples were prepared for mineralogical analysis. The pedon comparisons were performed to determine differences due to location and geomorphic surface, and due to drainage. Statistical results were then used to relate mineralogy, together with data on pH, CEC, and particle size distribution to pedogenesis in the area. Coastal Plain soils had sandier subsurface horizons than Piedmont soils. The above-scarp soils (> 75 meters) were the most mature Coastal Plain soils and approached the kaolinitic Piedmont soils reasonably well in mineralogy and particle size distribution. Coastal Plain soils were dominated by kaolinite, HIV, and gibbsite. Wet soils were less mature in mineralogy due to the lack of weathering activity. All but the Piedmont soils contained a surface mica enrichment, believed to be eolian additions. Well-drained and moderately well-drained soils had a more mature mineralogy than somewhat poorly and poorly drained soils. Kaolinite contents increased with depth whereas HIV contents tended to be concentrated in the A horizon. Despite the large clay content, the low charge nature of all soils should limit problems associated with clay dispersion practices during the mining. The low charge nature of the soils is reinforced by low ECEC data. / Master of Science