Amino acid compositions, bulk organic carbon, total nitrogen, and total organic matter were measured for eight sediment samples from the Hauraki Gulf, New Zealand, in order to assess the source and fate of organic matter in a shallow marine environment. Samples were collected from near-shore and off-shore shore sites, as well as from a site receiving freshwater input from multiple rivers. A comparison of carbon, nitrogen, and amino acid compositions of samples between 1 cm depth (Uhle 2004) and 5 cm depth was used to assess changes in organic matter composition through time. Amino acid analyses in particular should be effective in deciphering organic decomposition through both the presence and abundance of amino acids. C:N values, which range from 6.5-9.3, are typical for marine sediments and indicate that the primary source for organic matter is marine despite potential terrigenous input from the surrounding environment. This interpretation is supported by carbon isotopes (-20‰ and -22‰ for most sites) which is typical for marine-derived organic materials. C:N ratios do not appreciably vary from 1-5 cm depth, suggesting that there has not been significant depletion of organic matter in these young deposits. Furthermore, both D- and L-amino acids are present at 5 cm depth, supporting minimal organic matter decomposition. However, concentrations of amino acid decreases with depth, and the presence of D-alanine, D-aspartic acid, D-glutamic acid, glycine, and non-protein amino acids, at 5 cm depth, suggests at least a small contribution to the organic carbon source from bacteria. A decrease in δ15N with depth further suggests the possibility of bacterial reworking under anoxic conditions. Combined, these results support hypotheses of microbial reworking of organic matter through time, but are not clearly diagnostic of this process.

Fecal contamination leads to increased risk of exposure to enteric pathogens in aquatic environments used for drinking water, recreation, and commercial shellfishing. Current indicators of fecal contamination recommended by the EPA such as E. coli and enterococcus can fall short of meeting ideal indicator criteria by having widely-varying persistence in the environment, reproducing in the environment, occurring in the gut in low and variable concentrations, and requiring time-consuming assays. Furthermore, both these indicators lack the degree of host specificity needed for use in identifying sources of fecal contamination, which is an important tool for identifying and reducing fecal inputs to the aquatic environment. Preliminary studies have suggested bacteria belonging to the genus Bacteroides can be an alternative to current fecal indicators. This thesis assessed the utility of Bacteroides as a fecal indicator first through a review of the literature investigating the use of Bacteroides and highlighting current research needs. Next, a series of microcosm experiments investigating the effects of varying environmental parameters on the persistence of the Bacteroides 16S rRNA marker in stream water were performed. These studies used real-time PCR detection to develop decay curves for Bacteroides concentrations under different conditions of water filtration, initial fecal aggregate size, initial fecal concentration, temperature, and fecal source organism. Statistical models were used to determine the significance of the decay curves and identify those variables having the greatest significance to the rate of decline of Bacteroides. The results of this study indicated that filtration, temperature, and the initial fecal aggregate size had significant effects on the rate of removal of the Bacteroides genetic marker from stream water. The decline was significantly less in filtered (0.25 log removal/day) versus unfiltered stream water (0.67 log removal/day), 5 °C (0.32 log removal/day) versus 25 °C (1.62 log removal/day), and coarse (0.62 log removal/day) versus fine aggregate size (1.41 log removal/day). The initial concentration of fecal matter and the host organism did not have significant affects on removal. This suggests that the primary mechanism behind decline of the Bacteroides marker in stream water is biologic removal, such as grazing by protozoa or infection by bacteriophage. Finally, this thesis presents the development of the EqBac assay, a new quantitative PCR assay using the Bacteroides 16S rRNA gene from horses to detect equine fecal contamination.

Seasat, an orbital synthetic aperature radar launched in 1978, has produced high-resolution imagery enhancing over 1186 observed linear topographic indentations or lineaments in the Wartburg Basin area of east-central Tennessee. The main objectives of this thesis are to verify these lineaments in the field, to compare them with aerial photographic lineaments in the same area, to statistically analyze lineament trends, and to compare lineaments with oil and gas trends in the Wartburg Basin area.Lineaments from Seasat imagery were located in the field with a high degree of accuracy. Three distinct lineament systems were derived from lineament orientations, their grouping and continuity. There are two basic types of lineaments on the imagery, long lineaments that extend for distances over 40 km and shorter subparallel lineaments usually no longer than 4 km. 40% of the longer lineaments are parallel to drainage. Of the total 1186 lineaments, 40% are terminated by crosscutting lineaments. 57% of the total lineaments are related to aeromagnetic and gravity contours indicating a possible basement relationship. The longer lineaments possibly represent major bedrock penetrating fracture zones along which hydrocarbons disperse. Oil and gas wells farther from the lineament zones had a slight increase in initial hydrocarbon production, wellhead pressure and subsurface fracturing. This could indicate that future wellsites should be chosen away from major lineament zones.

Karst and fractured rock aquifers are primary sources of drinking water in the Appalachian region, even though most are inherently susceptible to surface-derived contamination. Many of the obstacles to water supply protection in such systems could be alleviated through the use of tracer testing to delineate recharge areas and surface-to-groundwater connections. Tracer testing is currently under-utilized, however, due to public safety concerns and ambivalence on the part of regulatory agencies. This study aimed to address this issue through a characterization of the fluorescent properties of typical carbonate aquifers for the purpose of refining the timing and design of low-concentration dye tracer tests. The subjects of this study were community water supply wells and springs in the Valley and Ridge Province of East Tennessee. Although each source exhibited a different degree of contamination potential, background fluorescence could primarily be attributed to natural dissolved organic matter (DOM) rather than manmade fluorophores. Seasonal data were collected for 23 groundwater sources during a multi-year drought (2006-2007). Untreated water samples were analyzed via fluorescence spectroscopy to identify spatial and temporal variations in the fluorescent properties of high-risk and low-risk water supply sources. Fluorescence exhibited seasonal patterns and fluctuations in DOM quality relative to rain events. Fulvic acid-like spectra were detected most consistently in all sources and exhibited maximum fluorescent intensity in the winter months. Humic acid-type fluorescence appeared in springs and high-risk wells only after major rainfall. For all sources, DOM spectra gradually shifted towards lower molecular weight fluorophores, which was interpreted as a reflection of diminishing humification and increasing generation of proteins with warmer weather and drier conditions. Variations in fluorophore composition and concentration were generally more pronounced in springs and moderate- to high-risk wells than in low-risk wells, although all sources exhibited some unique characteristics. The results indicate that extended background fluorescence characterization could enhance the design of tracer tests and sampling strategies for waterborne contaminants such as cyanotoxins, VOCs, and microbial pathogens. This study also highlights the potential benefits of monitoring DOM fluorescence as a natural tracer for source water and wellhead protection.

New field and laboratory data collected for the northeastern Inner Piedmont (IP) reveal the structure and composition of a portion of the southern Appalachian crystalline core, delimited the timing of orogenesis, and provide new insight into the nature of deep crustal processes during orogenesis. Previously recognized lithologies are continuous throughout the study area and comprise two distinct crystalline thrust sheets: the Marion and Brindle Creek thrust sheets, or eastern Tugaloo and western Cat Square terranes, respectively. Western IP Precambrian- Cambrian(?) metasedimentary lithologies and Ordovician metaigneous lithologies make up the Marion thrust sheet northwest of a Neoacadian suture, the Brindle Creek fault zone (BCFZ). To the southeast, the Brindle Creek thrust sheet contains Siluro-Devonian metasedimentary lithologies, which were intruded by Devonian anatectic metaigneous units. Rocks in the study area preserve a polyphase thermal, metamorphic, and deformational history. Textural evidence suggests that two high-temperature events, followed by a retrograde event affected these lithologies. Peak metamorphic conditions of 745°C and 7.1 kbar are estimated for eastern IP assemblages using garnet core compositional data. Garnet rim compositional data indicate a clockwise P-T path for eastern IP lithologies. This is supported by textural observations of sillimanite replacing kyanite, further suggesting prograde conditions during metamorphism. Northeastern IP lithologies retain evidence of six deformation events. The Mill Spring fault zone is recognized as a late dextral strike-slip fault that splayed from the Alleghanian Brevard fault zone. Map and outcrop-scale truncations of structures and lithologies of known ages provide relative and absolute timing constraints for IP orogenic pulses. Western IP D1 structures were produced by a pre-Neoacadian event, likely related to the 480-460 Ma Taconic orogeny. Eastern IP D1 structures are the product of initial subduction of Cat Square terrane lithologies beneath the Carolina terrane before BCFZ emplacement. D2 and D3 are responsible for regional structural trends, developed during the Neoacadian orogeny. SWvergent D4 dextral shear fabrics are related to dextral movement along the Alleghanian Brevard fault zone. Subsequent deformation features are brittle and result from Alleghanian uplift, and Mesozoic and Cenozoic extensional and rifting events. The presence of two ductile fault zones in the study area, the Tumblebug Creek fault zone (TCFZ) and the BCFZ, provides a unique opportunity to study the development of two crustal-scale structures in an orogenic core. Here, the relationships between mineral reactions, deformation mechanisms, fluid flow, volume loss, and mylonitization are investigated for two granitic mylonites. Fluid flow paths are interpreted from SW-trending regional linear fabrics. Shear zone formation is characterized by the breakdown of quartz and feldspar, coeval with the formation of myrmekite and biotite. Crystal-plastic mechanisms operating at temperatures >400°C were responsible for the deformation during shear-zone development. Silica and alkalis were lost during deformation, while immobile major and trace element concentrations remained constant. Volume losses of 41 and 48% occurred for the TCFZ and BCFZ, respectively. Zircon geochronologic data for northeastern IP lithologies provide new limits on the timing of orogenesis in the IP, and have produced a new developmental model for the Paleozoic development of the southern Appalachian crystalline core. Western IP Ordovician granitoids record the development of a volcanic arc system off of the Laurentian margin ~490 Ma. Taconic (480-460 Ma) arc accretion affected western IP lithologies, causing deformation, metamorphism, and magmatism. Eastern IP detrital zircon data indicate that the Cat Square terrane was being deposited after 430 Ma. Initial subduction of Cat Square sediments by the Carolina superterrane began by ~415 Ma. The Cat Square and Carolina terranes were accreted to the Laurentian margin together during the 360-340 Ma Neoacadian orogeny, causing the first shared thermal events between eastern and western IP terranes. Penetrative structures and dominant IP fabrics were developed during this event. Subsequent deformation occurred during dextral strike-slip motion along the Alleghanian Brevard fault zone.

Molar-tooth (MT) microspar is a volumetrically significant, globally distributed carbonate fabric that occurs almost exclusively in Mesoproterozoic and early Neoproterozoic shallow marine successions. It occurs as uniform, equant crystals, averaging 9 –15 μm in diameter (Figure 1), that characteristically fill MT structures—interconnected networks of spheroidal, spindle, and ribbon-shaped voids that formed within unlithified sediment in shallow, subtidal environments. Cathodoluminescence (CL) analysis of MT microspar reveals two chemically distinct phases: a dully luminescent spheroidal core enclosed by a luminescent, polygonal rim. Crystal size distribution analysis of MT microspar indicates spontaneous nucleation, rapid growth and varying degrees of recrystallization by Ostwald ripening, followed by precipitation of overgrowth cements. Petrographic and isotopic characteristics suggest MT microspar is a primary precipitate and not a diagenetic or neomorphic phenomenon and that precipitation occurred in active communication with Proterozoic seawater. Therefore, constraining the genesis of MT microspar is critical to understanding the geochemical evolution of Proterozoic seawater. Morphological similarities have led to comparisons between MT microspar and experimentally precipitated vaterite, a metastable CaCO3 polymorph. Presented here are results of precipitation experiments designed to investigate the plausibility of vaterite as the precursor mineralogy to MT cores, and to explore the geochemical conditions under which MT microspar may have formed. Any hypothesis for the formation of MT microspar must account for the crystal size and morphologies observed in MT microspar cores, as well the volume of precipitate needed to fill and stabilize MT structures. These experiments show that (1) spheroidal morphologies are common in both vaterite and calcite, suggesting that MT microspar may have initiated as a polymineralic precipitate and (2) that even under greatly elevated saturations, insufficient precipitate is produced to account for observed volumes of MT microspar. Experiments performed at elevated pH with added Mg2+, however, produced a viscous colloid, suggesting that under conditions of high carbonate saturation an amorphous phase of significant volume may have filled, and thus stabilized, MT structures in the unlithified substrate.

Several theoretical equations that predict sub-wavelength ‘thin-layer’ reflection amplitudes are compared to the results of a series of controlled ground penetrating radar surveys using 1 GHz transducers over a physical model of a horizontal bedrock fracture. Two large plastic (UHMW-PE) blocks, separated by one or more stacked inserts (polyethylene; ~0.1 mm thick) for a total of 101 surveys, generate a modeled fracture with an aperture ranging from 0-300 mm. All existing theoretical reflection coefficient equations fail to predict observed reflection amplitude oscillations in the data when the fracture aperture is less than 1/48 of a wavelength. The only theoretical formulation to properly predict any significant aspect of the fracture EM reflectivity is the Widess equation; however, the best fit only occurs where aperture sizes are less than 1/16, not 1/8 of the wavelength as predicted. Thermal expansion and temperature fluctuations do not sufficiently account for the oscillations. The influence of salinity on a water-filled sub-wavelength constant aperture (5 mm) fracture using 1 GHz antennas is also investigated. Results indicate that at this frequency, the reflection amplitude has a slight negative correlation with changes in salinity from 0-5700 mS/m.

Thesis (M.S.)--Oregon State University, 1981. / Typescript (photocopy). Includes bibliographical references (leaves 304-317). Also available via the World Wide Web.

Thesis (M.S.)--Oregon State University, 1981. / Typescript (photocopy). Includes bibliographical references (leaves 272-289). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 1981. / Typescript (photocopy). Includes bibliographical references. Also available online.