Nine basement blocks were sampled from locations spanning from Pennsylvania to Georgia in the eastern United States. These basement blocks are similar in that they have radiometric ages of approximately 1.0 billion years (with one exception), they are all at upper amphibolite to granulite grades, and are compositionally similar. Whole rock lead isotopic studies were performed on these samples in order to distinguish any possible differences in source regions that could be used to discriminate potential terranes within this 2700 km long region of the Appalachians. The lead isotopic system was used to decipher differences between these basement blocks. Traditional display of the data, in the form of ²⁰⁷Pb/²⁰⁴Pb-²⁰⁶Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb-²⁰⁶Pb/²⁰⁴Pb diagrams did not adequately bring out the similarities or differences in the data. Therefore, another method of displaying the data (e.g. Hart, 1984) was used in which the data from the Blue Ridge of Virginia was used as the reference against which all other data were compared. This method proved successful and trends were recognized. There are at least three different isotopic reservoirs within the central and southern Appalachians. There is the reservoir represented by the Blue Ridge of Virginia and six of the basement blocks that are isotopically similar (Honeybrook Upland, State Farm Gneiss, Sauratown Mountain, Tallulah Falls, Corbin Gneiss, and Pine Mountain), a second reservoir represented by the Baltimore Gneiss, and the third represented by the 1.8 billion year Carvers Gap Gneiss. The terrane that is represented by the Blue Ridge of Virginia and the six isotopically similar basement blocks is defined by ²⁰⁶Pb/²⁰⁴Pb ratios of 16.5-17.5, ²⁰⁷Pb/²⁰⁴Pb ratios of 15.4-15.5, and ²⁰⁸Pb/²⁰⁴Pb ratios of 36.0-37.0. The Baltimore Gneiss has ²⁰⁷Pb/²⁰⁴Ph ratios ranging from 15.2-15.6 and ²⁰⁸Pb/²⁰⁴Pb ratios ranging from 33.1- 38.1. These ratios although they show a broader range in values are elevated and suggest that the Baltimore Gneiss is isotopically different from the reference Blue Ridge. Carvers Gap Gneiss has ²⁰⁸Pb/²⁰⁴Pb ratios of 36.3-40.3 and ²⁰⁶Pb/²⁰⁴Pb ratios of 15.9-18.2. These ratios show that Carvers Gap Gneiss is isotopically dissimilar from the reference also. / Master of Science

The Striped Rock pluton of the late-Proterozoic Crossnore Plutonic-Volcanic suite is located beneath the Fries Thrust zone in the Blue Ridge province of southwest Virginia. The multiphase granite pluton has been affected by episodes of brittle and crystal plastic deformation at both the microscopic and mesoscopic scales. Brittle deformation preceded and postdated crystal plastic deformation. The pluton is cut by pervasive centimeter-scale cataclasite zones and ductile shear zones that vary in width from a few millimeters to several hundred meters. The majority of mylonite zones in the pluton strike east and northeast and are inclined moderately southeast. Cataclasite zones strike northeast and northwest. Deformation is most intense along the southern contact with the Cranberry gneiss where both pluton and country rock are deformed into a northeast-striking zone of mylonitic augen gneiss. The intensity of deformation decreases northwestward. Southeastdirected normal fault displacement is common to east and northeast-trending shear zones. A minor group of northwest-oriented shear zones dip moderately southwest and northeast and show sinistral, strike-slip displacement. Quartz-, chlorite- and stilpnomelane-filled cracks and veins with northeast and northwest trend uniformly overprint mylonite and cataclasite zones of all scales. Microstructure changes progressively with increasing strain. Feldspar grains are cut by at least two generations of mineralized, dilatant microcracks. Minerals precipitated in the early set of microcracks have undergone extensive crystal plastic deformation. Late-stage microcracks are filled with completely undeformed minerals. The spatial distribution of normal fault mylonite zones is geometrically consistent with generation during 1) late-Proterozoic extension, 2) Mesozoic extension, 3) rigid-body rotation during Paleozoic thrusting, or 4) "gravitational collapse" during Paleozoic thrusting. Field and microstructural evidence favor (4). The exact timing of deformation is not, however, well-constrained. / Master of Science

The Early Ordovician, Upper Knox Group consists of meter-scale shallowing-upward cycles that were deposited on a low-sloping ramp. Cycles formed in response to short term (<100 k.y.) eustatic sea-level fluctuations and typically have well developed tidal flat caps. Cycles are bundled into five transgressive-regressive sequences which correspond to third order (1-10 m.y.) sea-level fluctuations defined by Fischer plots. The Upper Knox Group is 90% dolomite of which greater than 75% predates Middle Ordovician, Knox Unconformity development. Early dolomitization occurred penecontemporaneously with tidal flat progradation during fifth-order (up to 100 k.y.) sea-level falls as indicated by: abundant dolomite in cycles with well-developed tidal flat caps and scarce dolomite in cycles with no or thin laminite caps; decrease in dolomite abundance with distance below tidal flat caps; dolomitized cycles decrease basinward; and dolomite clasts veneer cycle tops and the Knox Unconformity surface. Third-order sea-level fluctuations also strongly controlled early dolomitization as indicated by Fischer plots; limestone, subtidal-dominated cycles correspond to third-order sea level rises and completely dolomitized, peritidal-dominated cycles correspond to third-order sea level falls. "Early" dolomite was metastable and its geochemical composition was modified during initial stabilization by marine brines during progradation of each cycle, and by mixed fresh/marine waters of the Knox aquifer associated with unconformity development. Much "early" dolomite however, remained metastable into the deep burial environment where it was replaced and overgrown by burial fluids as suggested by: covariant trends between crystal size, mole % CaCO₃, Sr²⁺, Mn²⁺ and δ¹⁸O; similar regional trends defined by stable isotope values of "early" dolomites and burial dolomites; and water-rock modeling of trace element and stable isotopic trends. Trace element and stable isotope compositions of least-altered "early" dolomite however, record a memory of a precursor evaporative dolomite. Cathodoluminescent dolomite stratigraphy defines five generations of burial dolomite that can be correlated over 100,000 km². Burial dolomites postdate a regional dissolution event attributed to migration of organic acid-rich fluids through the Knox carbonates. Regional dolomitization occurred coeval with Late Paleozoic deformation and was closely associated with MVT mineralization and hydrocarbon migration. The δ¹⁸O values and trace element contents of burial dolomites in conjunction with fluid inclusions, suggest that burial fluids were warm (135 to 200°C), saline (13 to 22 wt. % NaCl equiv.), ¹⁸O-enriched (+2 to +9 % SMOW) fluids with geochemical compositions similar to present day basinal brines. Mn²⁺ and Fe²⁺ contents of the dolomites suggest a redox control over Mn and Fe fluid chemistry, and in conjunction with regional δ¹³C trends, likely record precipitation from organic acid-rich fluids. Regional trace element and δ¹⁸O trends record a basinal fluid source and regional northwestward flow. Stable isotope values of burial dolomites and fluid inclusions from dolomites and associated minerals, define a prograderetrograde sequence that formed during basinwide, gravity-driven fluid flow which developed in response to Late Paleozoic thrusting and uplift. / Ph. D.

Book Summary: World at War: Understanding Conflict and Society is an essential source of reference material on the military conflicts that have defined global history from antiquity to today. Through absorbing investigations of how the World War I peace settlement led to World War II, or insightful comparisons of U.S. past involvement in Southeast Asia with the Afghanistan War, this database encourages study and research that goes beyond isolated events to identify causal relationships, chart historical developments, and analyze the role conflict itself plays in society. Content quality is maintained by an expert advisory board, comprised of educators and historians including Dr. Spencer Tucker (the award-winning author of titles such as The Encyclopedia of Middle East Wars and American Civil War: The Definitive Encyclopedia and Document Collection).This advisory board also serves to vet the database's original journal articles, which expose researchers to scholarly argumentation on controversial topics in global military history.

Book Summary: Wars create important turning points in human history, defining our leaders and changing the lives of ordinary families and citizens. Whether fighting for independence, forging alliances, making a play for dominance, or battling a global threat, nations shape history—and the world—when they go to war. World at War: Understanding Conflict and Society presents overviews of 50 wars, rebellions, and revolutions, both those commonly taught and those less so, and provides additional analysis of causes and consequences and portraits of opponents. The effect is to elucidate the global impact of these military conflicts that have defined our world from antiquity to today such that students and researchers may develop a deeper, critical appreciation of both the history of the world and the human costs of war.

The role of fire in determining the structure and composition of many forested ecosystems is well documented (e.g. North American boreal forests; piñon-juniper woodlands of the western US). Fire is also believed to be important in temperate forests of eastern North America, but the processes acting here are less clear, particularly in xerophytic forests dominated by yellow pine (Pinus, subgenus Diploxylon Koehne) and oak (Quercus L.). In this study, I use dendroecological techniques to investigate fire history and vegetation dynamics of mixed pine-oak forests in the central Appalachian Mountains of Virginia. The study addresses three objectives: (1) develop a lengthy fire chronology to document fire history beginning in the late presettlement era and extending throughout the period of European settlement, industrialization and modern fire exclusion; (2) explore fire-climate relationships; and (3) investigate vegetation dynamics in relation to fire occurrence. The study was conducted on three study sites within the George Washington National Forest. I used fire-scarred cross-sections from yellow pine trees to document fire history. Fire-climate relationships were investigated for each study site individually and all sites combined using superposed epoch analysis (SEA). Fire-history information was coupled with dendroecological data on age structure to explore stand development in relation to fire occurrence. Results of fire history analysis reveal a long history of frequent fire with little temporal variation despite changes in land use history. Mean fire intervals (MFI) ranged from 3.7–17.4 years. The most important change in the fire regime was the initiation of fire suppression in the early twentieth century. Results of SEA show that periodic droughts may be important drivers of fire activity. Drought the year of fire was important at two of the three study sites and when all sites were combined. Results of age structure indicate that vegetation development was clearly influenced by fire. Frequent burning maintained populations of yellow pine throughout the period of study until fire suppression allowed fire-sensitive hardwood trees and shrubs to establish. It is clear from this study that continued fire suppression will likely result in fire-tolerant pines and oaks being replaced by more mesophytic trees and shrubs.

Thesis (D. Min.)--Liberty Baptist Theological Seminary, 1999. / Includes bibliographical references.

The purpose of this study is to provide a habitat analysis of the Yellow-bellied Sapsucker, Sphyrapicus varius, in the Southern Appalachians. This population of S. varius is unique because it breeds in the high elevations of the Southern Appalachians, while the northern population breeds from Pennsylvania to Alberta Canada. Albert Ganier described this population in 1954 (Ganier 1954). Using the Relevee method of habitat analysis I have described the territories of several breeding pairs in the Southern Appalachians. This analysis suggests that these birds require an open canopy of northern hardwood forest with some type of open area as a part of their territory. I have measured several other factors of the habitat as well. The information obtained in this study will be used to guide management practices to maintain and increase the population size of S. varius ssp. appalachiensis.

National Forest timber management in the southern Appalachians is changing from traditional even-aged management and clearcutting to uneven-aged management and group selection silviculture. Group selection, with its small 1/2-to-2-acre patch cuts widely dispersed throughout a timber stand, has the potential to substantially increase timber harvesting costs over traditional clearcutting. This could exacerbate the below-cost timber sale issue. The objective of this study was to assess the impact of groups election silviculture on timber harvest productivity and cost in hardwood stands of the southern Appalachians. This was accomplished by collecting and analyzing field production and cost data from typical Appalachian loggers operating on group-selection timber sales. Three logging systems were chosen for the study: (1) cable yarder ,(skyline) system; (2) feller-buncher/cable skidder system; and (3) motor-manual chainsaw felling/cable skidding system. At least one full week of time-study production data was collected at each location. cost information was obtained from the cooperating loggers' records, as well as historic production and cost data from previous clearcut sales for comparison purposes. study results show that production was reduced and unit cost increased for all three logging systems when operating on group-selection timber sales as compared to clearcutting. unit cost per ton for the cable yarder system was $40.18, a 29 percent increase over their previous average clearcutting cost. The fellerbuncher/cable skidder system unit cost per ton was $14.79, a 19 percent increase over this system's average clearcutting cost. The chainsaw felling/cable skidder system cost of $16.15 per ton was 33 percent above their normal clearcutting cost. A large increase in delays and unproductive time as a result of specific group-selection timber sale characteristics appears to be the major cause of reduced logging productivity and increased costs. / Master of Science

No description available.