The first comprehensive year-round investigation of Mountain Lake, Virginia since 1970-71 was begun in March 1985 and continued through November 1987. Monthly studies suggested that this unique natural lake is undergoing change. Whereas inorganic nitrogen, orthophosphate, Secchi disc transparency, and primary productivity continue to suggest an oligotrophic condition, important limnological changes are indicated by the greater seasonal hypolimnetic oxygen depletion and extractable chlorophyll a which at times approach mesotrophic levels. In addition, the decrease in alkalinity, the increase in sulfate levels, and the increase in pH fluctuations compared to the past, suggest that Mountain Lake is susceptible to damage or change by acid rain and perhaps other perturbations that effect pH alkalinity, or hardness. Changes were also noted in phytoplankton composition. One hundred sixty-three taxa were identified which included 56.4% Chlorophyta, 17.8% Chrysophyta, 13.5% Cyanophyta, 8% Pyrrophyta, 3.7% Cryptophyta, and 0.6% Euglenophyta. Sixty percent of these taxa were new reports for Mountain Lake. Dominant pyrrophytes included Gymnodinium sp. and Peridinium wisconsinense. Dominant chlorophytes included Scenedesmus bijuga, Quadrigula chodatii, and Oocystis pusilla. Important cryptophytes were Cryptomonas erosa var. reflexa, C. pusilla, and C. pyrenoidifera. The most abundant cyanophyte was Aphanocapsa elachista var. conferta. The only diatom (chrysophyte) that ever dominated was Cyclotella meneghiniana. Studies of ammonia uptake by the phytoplankton, using the ammonia analog [¹⁴C]methylamine (MeA), revealed that during thermal stratification, phytoplankton succession was related to rapid ammonia uptake. Each successive phytoplankton community had significantly higher Vmax values for ammonia (methylamine) until midsummer when ammonia-nitrogen levels were at a seasonal low. At that point, the Vmax values dramatically declined and the community became dominated by blue-green algae. When allochthonous inputs of inorganic nitrogen renewed the levels of ammonia-nitrogen, Vmax values increased and the community changed, replacing the blue-green algae. Communities dominated by green algae (Chlorophyta) had higher MeA (and thus ammonia) uptake rates than those dominated by cryptophytes or blue-green algae (Cyanophyta). The effect of various treatments and inhibitors on MeA uptake by the phytoplankton support the conclusion that ammonia uptake is a chemical, light-independent, energy-dependent process. / Ph. D.

The East River Mountain district. located in Tazewell and Bland counties. Virginia. is an area of approximately 80 square miles much of which is underlain by ferruginous sandstones of Clinton age. The extensive areas of outcrop of the ferruginous sandstone make large tonnages of the rock readily available for open-pit quarrying. Investigations show that within the area studied over 60 million tons of hematite were contained in the ferruginous sandstones present in the East River Mountain district. Thus these sandstones constitute a large potential for commercial iron ore if extraction is possible. In September of 1956 9 laboratory study of the ironbearing sandstones was inaugurated primarily to discover a commercially feasible method of beneficiating and concentrating the hematite contained in the sandstones. High-tension electrostatic, wet and dry magnetic. and ultrasonic methods of extraction were studied. Of these methods ultrasonic insonation of the ferruginous sandstone appears to hold the most promise for obtaining satisfactory concentrates of hematite from the sandstone. A marked upgrading of the hematite content was noted after the crushed iron-bearing sandstones were subjected to ultrasonic insonation at a frequency of 22 kilocycles. The ultrasonic treatment used to concentrate the hematite appears to be both adaptable and economical on a commercial scale. / Master of Science

I studied aspects of the population ecology of table mountain pine, <i>Pinus pungens</i>, in pine-oak forests on Brush Mountain, Montgomery County, Virginia. The objective of this study was to examine the age structure and recruitment dynamics of <i>P. pungens</i>, a fire-adapted conifer, and to determine whether <i>P. pungens</i> populations would persist in the absence of fire. The age distributions of <i>P. pungens</i> on the Brush Mountain study sites were bimodal, with peaks in seedling and canopy age classes and a major trough in the sapling and understory age classes. Age and diameter of <i>P. pungens</i> understory and canopy trees were positively related, but diameter was a poor predictor of age. The sparse representation of <i>P. pungens</i> in the seedling, sapling, and understory strata of the Brush Mountain sites strongly indicates that under current disturbance regimes, maintenance of <i>P. pungens</i> populations is unlikely. The prevalence of oak advance regeneration ard other gap-exploiting woody species such as ard <i>Sassafras albidum</i> and <i>Nyssa sylvatica</i> suggests that gap replacement processes would favor these species and not <i>P. pungens</i> Recruitment of <i>P. pungens</i> was not limited by seedfall from serotinous cones or from seed predation by animals. Seedfall occurred throughout the year at low levels and was concentrated in the spring and summer months. The unavailability of seedling habitat strongly limited recruitment of <i>P. pungens</i> seedlings. Litter depth and type were important determinants of <i>P. pungens</i> seedling habitat; seedlings occurred almost exclusively in shallow pine litter. There was little overlap between the distributions of habitat variables for seedlings and random points in the forest, indicating that suitable seedling habitat was rare. Summer drought and substrate were important factors influencing the establishment and survivorship of seedlings. Greenhouse studies were conducted to determine the influence of leaf litter and water regime on early establishment of <i>P. Pungens</i>. Emergence of seedlings was consistently highest in pine litter and lowest in hardwood litter at all water regimes and in litter-free treatments at low watering intervals. Survival of seedlings was enhanced by litter at low water regimes. Significant litter/water interactions indicated that the effects of litter and water regime were not independent; litter significantly decreased the loss of soil moisture from experimental treatments. Evidence suggests that depression of <i>P. pungens</i> seedling emergence in hardwood litter was due to physical-mechanical effects. / Ph. D.

No description available.

The Ellensburg Formation, preserved in the Nile basin 50 km northwest of Yakima, Washington, consists of a series of middle to late Miocene epiclastic and pyroclastic rock assemblages rich in porphyritic hornblende-biotite dacite. Geochemical, petrographic, and stratigraphic correlations indicate that Old Scab Mountain, a dacite porphyry intrusion, located at the western margin of the basin (lat. 46°53'30", long. 121°13'00"), is the probable source for much of the upper Ellensburg volcaniclastic material in the basin. The dacite intrusion exposed at Old Scab Mountain was emplaced at depths of 1 to 3 km and underlaid a now eroded volcanic edifice. This volcanic center is interpreted to have been active during the time of deposition of the upper Ellensburg Formation. AK-Ar age of 8.75 ± 0.20 Ma for an adjacent sill of similar dacite suggests an age for Old Scab Mountain between 9 to 7 Ma (Smith, 1988a). This age corresponds with the upper Ellensburg Formation which stratigraphically overlies Grande Ronde Basalt lava flows of the Columbia River Basalt Group, within the basin. Stratigraphic reconstruction of the Nile basin deposits indicates a dome collapse eruptive style. Progressive dome growth was punctuated by short-lived eruptions resulting in dome collapse and deposition of debris-avalanche and lahar deposits. These deposits were remobilized by fluvial processes which generated thick conglomerates and interstratified volcanic sandstones. Upper Ellensburg deposits and dacite of Old Scab Mountain are calc-alkaline and medium-K in composition. Silica content ranges from 53 to 67 weight percent Si02 for upper Ellensburg deposits and 66 to 67 weight percent Si02 for dacite of Old Scab Mountain. Older deposits composing the lower Ellensburg Formation are interbedded with and underlie the Grande Ronde Basalt. The lower Ellensburg deposits are typically more tholeiitic, range from 56 to 74 weight percent Si02 , and show slightly higher trace element concentrations than the upper Ellensburg deposits. These deposits were possibly derived from other dacite centers located near the headwaters of the adjacent Naches basin.

The Dooley Rhyolite Breccia in northeast Oregon was erupted between 12 and 16 million years ago, from central vents and linear feeder dikes within the Dooley Mountain quadrangle. The peraluminous, high-silica rhyolites of the formation were erupted over an irregular highland of eroded pre-Tertiary metamorphic rocks locally overlain by intracanyon, Eocene Clarno-type basalt flow(s) . The Dooley Rhyolite Braccia is exposed in a tectonically disrupted, north-south trending graben across the Elkhorn Range. The formation is variable in thickness with maximum thickness exceeding 660 meters in the south and 600 meters in the north half of the quadrangle. Volumetrically the formation is dominated by block lava flows with lessor associated volcaniclastic and pyroclastic rocks. Although initial and waning phases of eruption of the formation produced ash-flow tuffs which extend well beyond the quadrangle boundaries, volcanism within the quadrangle appears to have been primarily effusive. At least nine geochemically distinct rhyolite subunits belonging to four related chemical groups have been identified in the formation stratigraphy which appear to represent unique eruptive episodes. Chronologic geochemical patterns within the formation are consistent with a petrogenetic model of repeated partial melting and eruption from multiple silicic magma chambers in an attenuated continental crust. Basalts correlative with the Powder River Basalt and the Strawberry Volcanics overlie the Dooley Rhyolite Braccia on the north flank of Dooley Mountain. Cale-alkaline basalts correlative with the Strawberry Volcanics are overlain by thoeliitic basalts of uncertain affinity on the south flank of the mountain. These basalt flows on respective flanks of the mountain were not continuous across the quadrangle. Rhyolitic volcanism in the Dooley Mountain quadrangle is contemporary with the strawberry Volcanics and the Picture Gorge Basalt of the Columbia River Basalt Group.

Four 286m2 plots on alternate sides of the spur ridges on Brush Mt. were established and their plant communities characterized. Agaric and Bolete basidiomycetes were sampled for two years. Fifty species were recorded on the plots. Phenologically, decomposer species were highly dependent upon rainfall events, whereas mycorrhizal species were more seasonal. Two species emerged as dominant litter decomposers. Marasmiellus praeacutus (Ellis) Halling is dominant on southwest facing slopes and occurs on a wide variety of coniferous and hardwood detritus. Collybia subnuda (Ellis ex. Peck) Gilliam is dominant on northeast facing slopes, and occurs on hardwood leaves and small woody detritus. The population structure of both of these species was investigated using tests of somatic incompatibility. Genets of both species are able to persist for more than one year. The observed minimum population density is 0.071 - 0.121 genets/m² for M. praeacutus and 0.039 - 0.093 genets/m² for g. subnuda. Mating tests indicate that M. praeacutus is heterothallic and tetrapolar, and that C. subnuda is heterothallic and bipolar. Preliminary crosses between monokaryotic tester sets indicate a surprisingly low number of mating alleles in both species. Decomposition studies suggest that while the restricted distribution of ~. subnuda to the northeast slopes may be affected by substrate specificity, the restriction of M. praeacutus to the southwest slopes is due to other factors. / Master of Science

The attributes of alewife and gizzard shad as coexistent forage fishes for striped bass (Morone saxatilis), walleye (Stizostedion vitreum vitreum) and largemouth bass (Micropterus salmoides) were evaluated in Smith Mountain Lake, an 8,337 ha hydroelectric impoundment in south-central Virginia. Alewife and gizzard shad larvae exhibited strong spatial segregation which minimized the potential for direct trophic competition and increased feeding opportunities for piscivores. Gizzard shad spawning peaked in June while alewife spawning peaked in July. Daily growth rate of age-0 gizzard shad was 37% greater than for age-0 alewives. Later spawning and slower growth enhanced temporal and morphological availability of alewives to piscivores and reduced the potential for exploitative competition between the clupeids. Distributional analysis indicated that gizzard shad were primarily uplake and littoral while alewives were mostly downlake and pelagic. Alewives co-occurred with striped bass and walleye during the growing season and were crucial in providing forage for these piscivores. Largemouth bass shared a common distribution with gizzard shad and were more trophically dependent than other piscivores on them. Prey supply and predator demand were one year out of phase; gizzard shad and alewife production peaked in the first year of life while their predators' cohort production peaked in the second year. Cohort production analysis indicated that over their lifespan, striped bass prey demand (per 1000 fish) would exceed that of walleye and largemouth bass by 17% and 166%, respectively. Lifespan cohort production patterns and ingestibility limitations on prey assured that most predation pressure in Smith Mountain Lake came from piscivores ages 0-2 and was constrained to alewives ages 0 and 1 and young-of-the-year gizzard shad. Prediction of patterns of consumption of alewife and gizzard shad by piscivores was derived from analyses of morphological and distributional availabilities; these agreed closely with actual diets for most predator-prey location, season and age combinations. The alewife appears to be both compatible with, and complementary to, the gizzard shad as a forage species in Smith Mountain Lake. Suitability of alewives for introductions into other reservoirs will vary with the morphometry and management objectives for those waters. / Ph. D.

Master of Science / Department of Geology / Charles G. Oviatt / The Dyer Mountain quadrangle, located in Utah approximately 200 km east of Salt Lake City and 20 km north of Vernal, lies on the south flank of the east-west trending Uinta anticline. The topography of the area varies from mountain peaks to deep canyons, with rolling hills of uplands in between. The elevation in the quadrangle ranges from 3124 m (10248 ft) at the top of Dyer Mountain to 1835 m (6020 ft) at the lowest point of Big Brush Creek. Most of the northern portion of the quadrangle is vegetated by aspens and pines, whereas the southern part of the quadrangle is covered with sagebrush and grasses. Due to its location on the anticline, the quadrangle contains bedrock that dips gently to the south and southeast. The ages of the rocks within the quadrangle range from the Precambrian Uinta Mountain Group to the Quaternary and Tertiary gravels. Also present are the following formations: Cambrian Lodore; Mississippian Madison, Doughnut, and Humbug; Pennsylvanian Round Valley and Morgan; Pennsylvanian to Permian Weber; Permian Meade Peak Member of the Phosphoria and Franson Member of the Park City; and various Quaternary sediments. The Lodore Formation and the Madison Limestone rest on major unconformities, and the Quaternary and Tertiary gravels overlie the Gilbert Peak erosion surface. The Uinta anticline and southerly dip of the Proterozoic and Paleozoic rocks are a result of Late Cretaceous uplift during the Laramide orogeny; Tertiary rocks within the area show little to no deformation. Limestone and various types of ores have been mined in the quadrangle, and phosphorous is currently being mined for fertilizer production. Several landslides, common at the juncture of the Quaternary and Tertiary gravels and Permian shales, were identified within the quadrangle. An anticline and syncline, trending northwest to southeast, lie in the southeast portion of the quadrangle and transect Big Brush Gorge. Geologic hazards of the area include landslides, erosion and failure of road grades, and cliffs near trails. The karst topography of the area presents dangers of sink holes, and evidence of ceiling collapse is present within Big Brush Cave, a popular destination for tourists and cavers.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Mary Catherine E. Kingery-Page / Currently, about 15-20 percent of the worldwide tourist industry, or 70-90 billion dollars can be accounted for annually by mountain tourism (Price et al. 1997). The base of mountain tourism lies within the profound natural features of the surrounding mountain landscape. Therefore, maintaining clean cool air, dramatic variations in topography, and scenic beauty of both the physical and cultural landscapes are imperative. The following project addresses the issue of designing a sustainable mixed use community within the broader context of a top rated mountain resort. Within the last decade as public awareness of green practices has increased, so has the public’s knowledge of terms such as LEED (Leadership in Energy and Environmental Design), sustainability, and mixed-use development. Starting in 1995 a sustainable visioning plan emerged for the future development of the Greater Wasatch in Utah. The project, titled Envision Utah Quality Growth Plan, has been widely recognized as one of the country’s most successful efforts to involve the public in regional visioning. The proposed addition to Park City Mountain Resort in the Wasatch Front has been fueled by a desire to create an ecologically, socially, and economically sustainable mixed-use development. The Envision Utah Quality Growth Plan and a precedent study in Whistler, combined with literature by Peter Calthorpe, Sherry Dorward, and Ian McHarg, provided the foundation for a sustainability assessment framework. The framework is applied to test the sustainable viability of existing resorts, as a guide for the design of resorts, and as a tool for comparative analysis between mountain resorts. The result is a conceptual master plan for Park City, Utah that employs the use of stormwater and architectural best management practices, recycled materials, mixed use design, alternative forms of energy, and an efficient public transportation system.