<p> Soil CO₂ concentrations and soil temperature data were collected at the main field site, Rock Chapel Sanctuary, over a period of six months (July-December, 1981). Measurements were made under three vegetation types and at depths of 10, 25, and 50 cm beneath each vegetation type. Analysis of variance testing of the data set shows that at Rock Chapel soil temperature is not a significant source of variation in CO₂ concentrations. Furthermore depth beneath the soil, but not vegetation type, was found to be a significant source of variance in CO₂. </p> <p> As a secondary part of the project the Dräger and vacutainer methods of soil air sampling were tested and compared. Both methods were found to be approximately equal in accuracy. The vacutainer method suffers from storage and internal pressure problems however it is a useful method when collecting large numbers of samples from permanent sites. The Dräger method is invaluable in remote locations and works best with small sample volumes. </p> <p> The collection of soil CO₂ data should be done according to a well constructed sampling design otherwise much information regarding the effects of depth, vegetation type and other factors on CO₂ concentrations will be lost. </p> / Thesis / Master of Science (MSc)

<p> Gypsum karst areas in British Columbia and Wood Buffalo National Park, Alta.-N.W.T. are described. Investigation of the geo-hydrology of these areas, particularly specifically the saturation states of rising waters, is demonstrated to be a valuable tool in defining the major geomorphic processes acting. The combination of thermo-dynamic equilibrium studies of the gypsum and limestone processes serves to define zones within which the dominant controls of rock solution can be inferred.</p> <p> The commonly accepted parameters of limestone solution equilibria (Picknett's curves) are examined and shown to be incorrect. Use of the parameters and indices presented in this thesis gives much better accordance with observed characteristics of karst waters. </p> / Thesis / Master of Science (MSc)

Karst waters serve as important water sources in rural Appalachia and are well-connected to surface waters, making them susceptible to anthropogenic contamination, including by fecal indicator bacteria which represent a public health risk. This work designed and implemented a watershed-scale monitoring program for a 26 km2 sinking stream system in southwest Virginia to determine the fate and transport of E. coli in the system. This hydrologically complex watershed is predominantly agricultural and includes multiple key surface water sinks that enter Smokehole Cave and emerge at Smokehole Spring. Field campaigns at surface sites and within Smokehole Cave included bacteriological sampling, hydrologic measurement, and dye tracing. Field data was synthesized to: 1) examine variations in E. coli concentrations in the watershed during varying flows/seasonal conditions; and 2) calculate E. coli growth/decay coefficients for the karst system during different flow/antecedent conditions. E. coli concentrations at Smokehole Spring consistently peaked days after peak hydrologic stage. Flow conditions and storm event response were the largest drivers of E. coli transport through the system. Dye trace results revealed that water from sinks can be stored or move slowly through the karst system, resurging during storm events. E. coli was calculated to decay within the karst system, with a half-life of about 5-120 days which is longer than the travel time of water through the cave of approximately 0.5-2 days. Findings indicate that E. coli transport in Appalachian karst systems is hydrologically driven, roadside spring water collection is not recommended, and bacterial treatment is encouraged if performed. Targeted land-management practices should be explored to decrease E. coli loadings in karst waters. / Master of Science / Karst (cave) waters serve as important water sources in rural Appalachia and are well-connected to surface waters, making them susceptible to contamination from human or animal waste – a public health risk. A field monitoring program was conducted in an agriculturally impacted stream and cave system in southwest Virginia to determine how E. coli, a bacteria found in the waste of humans and other animals, moves through the system. There are several places where surface water sinks into the cave system, eventually entering Smokehole Cave and emerging at Smokehole Spring. Field data collection was performed at surface sites and within Smokehole Cave including sampling for E. coli, water flow measurements, and dye tracing. Field data was combined to 1) examine variations in E. coli concentrations during varying flows/seasonal conditions and 2) calculate E. coli growth/decay coefficients for the cave system during different flow and soil moisture conditions. It was found that E. coli concentrations at Smokehole Spring consistently peaked days after the water depth. Flow conditions and storm events were the largest drivers in E. coli movement through the system. Dye trace results revealed that water from sinks can be stored or moves slowly through the cave system and resurges during storm events. E. coli was found to decay within the cave system. Findings indicate that E. coli movement in Appalachian cave systems is driven by storm events, roadside spring water collection is not recommended, and bacteria treatment is recommended if performed. Cave-specific land-management practices are recommended to keep E. coli from entering cave waters.

Tinian and Aguijan, Commonwealth of the Northern Mariana Islands (CNMI), are volcanic, back arc islands in the western Pacific formed by Pacific Plate subduction under the Philippine Plate. The islands are composed of Eocene volcanic cores mantled by Plio-Pleistocene carbonate facies and raised Holocene beach and reef deposits. The entire sequence has been tectonically uplifted and contains high-angle normal faults, while isostatic subsidence and scarp failures overprint tectonic brittle failure features. A cave and karst inventory on Tinian and Aguijan surveyed 114 features and is believed to adequately represent the megaporosity (cave) development. Two distinct cave classes were identified: mixing zone caves (flank margin caves and banana holes) and fissure caves. Most mixing zone caves were located in or near scarps and coastlines, often at similar elevations to nearby caves. Fissure caves were located in regions of brittle failure, forming linear features with narrow widths. Three previous sea-level positions were identified based on horizons of mixing zone caves. Seventeen freshwater discharge sites and four allogenic recharge sites were identified on Tinian. Kolmogorov-Smirnov statistical analyses and rose diagram comparisons of orientation trends found significant similarities between megaporosity and geologic structure (brittle failure) on Tinian. Analyses of small regions showed distinct relations between brittle deformation and megaporosity, while at larger scales similarities became less obvious due to the complex geologic history and physiography of the island. Based on similarities in populations of orientation trends, fissure cave development is primarily controlled by brittle failure deformation with development along faults, fractures, and joints, while mixing zone cave development is primarily controlled by fresh-water lens position but significantly influenced by brittle failure deformation. Tinian and Aguijan do not fit neatly into one classification of the Carbonate Island Karst Model. Regions of Tinian best fit the Simple, Carbonate-Cover and Composite Island Karst Models, but none easily fit the entire island. Aguijan must be classified as a Simple Carbonate Island because no geologic data has proved the presence of non-carbonate rocks interfering with the fresh-water lens, however it is probable that Aguijan does contain basement rocks that extend above sea-level as on other carbonate islands in the Marianas.

Flank margin caves are karst features that develop in the freshwater/saline mixing zone within the carbonate islands of the Bahamas. The flank margin caves that are currently exposed developed during the last interglacial sea level highstand (+6 m; ~125 ka). Initially small ovid chambers, the caves increase in size to about 100 m2, then interconnect with adjacent chambers to form medium-sized caves. At about 1000 m2, these medium-size caves interlink forming large caves that are laterally extensive, vertically restricted, do not penetrate the fresh-water lens a significant amount, and run parallel to the axis of the ridge in which they formed. Small caves have a much smaller area to perimeter ratio than do large caves. As cave chambers grow and interconnect, perimeters become much more complex, and the number of bedrock columns in the cave increases. These results have implications for water resource management, and porosity modeling.

The Oakohay Creek watershed in Smith County, Mississippi, had been proposed as a site for the development of a reservoir. The site has been assessed for hydrogeologic suitability. There were three components to the site assessment. The first component involved examining the hydrologic characteristics of the drainage basin. Discharge and stage were monitored at eight sites, providing data for the development of hydrographs. The second component of the study was based on studying the site?s geology. The geology was studied through field reconnaissance, surface mapping, interpretation of geophysical well log data, and development of cross sections. The third component of the study involved the assessment of water quality within the basin. Samples were taken for analysis by the Mississippi State Chemical Laboratory. The results of the site assessment indicate that the proposed site is not suitable based on the hydrology, geology, and water quality of the study area.

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This work focuses on the operational and safety issues associated with karst voids in large opening underground mines. Issues include water inrush, structural instability, and engineering uncertainty in these environments. Coupled with the fracturing prevalent in folded sedimentary rocks, karsts are complex and challenging ground control risks. Traditional methods of predicting karst void locations such as probe-drilling are impeded by the inconsistent spatial distribution and variable sizes of the features. Ground penetrating radar (GPR) is a geophysical technique that transmits radio waves into a medium and subsequently detects reflected waves via a receiver. The travel time and energy of received signals are then processed and interpreted. The difference in material properties between limestone and open karst voids causes strong reflections. This work summarizes a series of 2D and 3D GPR surveys for karst void mapping within a mine pillar and within sill pillars between mine levels in a large opening underground limestone mine. In this case study mine, karst voids are hazardous ground control risks that interact with geologic discontinuities, creating free blocks within the rock mass. As tunnels are advanced via blasting, unknown karst voids may be exposed and pose risks to mining personnel. The karst voids also form a hydrogeological network of water reservoirs with spatial locations throughout the rock mass that are difficult to predict with traditional methods such as drilling. While GPR has been utilized throughout several industries for anomaly detection, mapping, and validating other geophysical data sets, this technique has not seen the same proliferation within the mining industry. Regarding published literature, there is a lack of works that detail the applicability of GPR in underground mining scenarios. The aim of this work is to expand on previous methodologies establishing GPR as a useful tool in underground mining applications, and to discuss the benefits and limitations GPR data in such scenarios. / Master of Science / This work focuses on the operational and safety issues associated with karst voids in large opening underground mines. Typical issues include water flooding into the tunnels and rocks falling out from the roof and walls, among other things. Sedimentary rock structures sometimes are geologically complex, and karst voids only add to that complexity. Engineers usually predict karst void locations with drilling or statistics, but this is often challenging as karst voids have various shapes and orientations. Ground penetrating radar (GPR) is a geophysical technique that sends electric signals into the rock; these signals can reflect off of karst voids and other anomalies. The travel time and energy of signals that come back to the antennas are then processed and interpreted. The difference in material properties between limestone and open karst voids causes strong reflections. This work shows a series of 2D and 3D GPR surveys for karst void mapping within a pillar in a stone mine and also below the floor of mine tunnels. In this mine, karst voids are very dangerous and the miners spend significant time and resources to ensure the tunnels walls are stable. As tunnels are blasted, hidden karst voids may be exposed and pose unpredicted risks to miners. The karst voids are also connected by cracks and discontinuities, providing a path for water to travel along. While GPR has been used in various ways among the construction, civil engineering, and tunneling industries, there is not enough literature pertaining to its benefits for mines. The goal of this work is to grow the available literature on GPR in mining and to talk about the best practices for GPR use as a means of improving health and safety for miners underground.