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Full-Text Articles in Physical Sciences and Mathematics

In Situ Studies Of Limestone Dissolution In A Coastal Submarine Spring, Rachel Marie Schweers Nov 2015

In Situ Studies Of Limestone Dissolution In A Coastal Submarine Spring, Rachel Marie Schweers

USF Tampa Graduate Theses and Dissertations

Limestone dissolution in karst environments is likely due to geochemistry of the water, the actions of microbial communities, and the effect of water flow. We explored the rate of limestone dissolution and will examine here the microbial communities associated with the limestone. A conduit within the brackish cave, Double Keyhole Spring, on the coast of central west Florida was the site of the experiment. PVC pipes (5cm x 16cm) were filled with crushed limestone that was screened to a 1.9cm – 2.54cm size range. There were three treatments (5 replicates each): Control - sealed autoclaved controls with limestone and conduit …


Stable Isotopes As A Tool To Characterize Carbon Cycling And Develop Hydrologic Budgets In Mantled Karst Settings, Katherine Knierim May 2015

Stable Isotopes As A Tool To Characterize Carbon Cycling And Develop Hydrologic Budgets In Mantled Karst Settings, Katherine Knierim

Graduate Theses and Dissertations

Isotopes of water (δ2H/δ18O), carbon dioxide (δ13C-CO2), and dissolved inorganic carbon (δ13C-DIC) were used to explore water quality, trace carbon cycling, and quantify recharge sources through mantled karst and into Blowing Spring Cave (BSC). Of the possible sources of contamination in the BSC recharge area, septic-tank effluent was hypothesized to degrade water quality at the spring outlet of BSC because of the dominance of septic tanks for waste treatment, unsuitable topography and soil for septic-tank absorption fields, increased nitrate and chloride concentrations concomitant with increased urbanization, and increased Escherichia coli with discharge. Carbon cycling between the soil and BSC was …


Controls On Dissolution Rate Variation At A Pair Of Underflow-Overflow Springs At The Savoy Experimental Watershed, Kiefer Allen Vaughn May 2015

Controls On Dissolution Rate Variation At A Pair Of Underflow-Overflow Springs At The Savoy Experimental Watershed, Kiefer Allen Vaughn

Graduate Theses and Dissertations

Physical dissolution experiments and numerical modeling have been used in the past to study limestone dissolution rates. Numerical models have typically used constant dissolution rates, whereas rates in nature vary in time. Limestone tablets allow natural estimation of rates over month time scales, but these rates cannot necessarily be extrapolated to geologic timescales and also do not aid our understanding of short term variability. This study characterizes natural variability in these rates and examines potential causes of that variability from first principles. This may enable more accurate projections of dissolution rates within models. This study combines measurement of physical and …


Carbon Isotope Variations Associated With A Middle Ordovician Karstic Unconformity, Patricia Suzanne Williams May 2015

Carbon Isotope Variations Associated With A Middle Ordovician Karstic Unconformity, Patricia Suzanne Williams

UNLV Theses, Dissertations, Professional Papers, and Capstones

Large negative carbon isotope (δ13C) excursions have been documented from late Neoproterozoic-Paleozoic successions. These δ13C excursions have been widely used for regional and global stratigraphic correlation, particularly in strata with limited paleontological and radiometric age controls. Recent studies, however, argued that some negative δ13C excursions from stratigraphic record may have been resulted from meteoric/burial diagenesis, which commonly shifts both carbon and oxygen isotopes toward lower values. Testing the diagenetic origin of δ13C excursions in stratigraphic successions without independent stratigraphic framework has been difficult because it evolves into circular arguments about stratigraphic completeness …


Impact Of Antecedent Groundwater Heads And Transient Aquifer Storage On Flood Peak Attenuation In An Unconfined Karst Aquifer: Study Of The Upper Suwannee River, Florida, Usa., Jeremy Loucks Jan 2015

Impact Of Antecedent Groundwater Heads And Transient Aquifer Storage On Flood Peak Attenuation In An Unconfined Karst Aquifer: Study Of The Upper Suwannee River, Florida, Usa., Jeremy Loucks

Dissertations, Master's Theses and Master's Reports

Flood peak attenuation is an important aspect of understanding flooding and its effects. Few studies exist that look at the effects of ground-surface water interactions in regards to peak attenuation, and fewer still focus on karst environments. In the karstic, variably confined Suwannee River Basin, discharge, river stage, and water table data that were collected over a ten-year period were analyzed to determine the relationship between antecedent groundwater head and flood peak attenuation. Flooding causes high hydraulic heads in the river, which rise faster than corresponding groundwater heads. Springs which normally feed groundwater into the river reverse flow, and conduits …


Tracing Sediment In The Subsurface Using Beryllium-7: Green River Basin, Ky, Caroline Adams Broderick Jan 2015

Tracing Sediment In The Subsurface Using Beryllium-7: Green River Basin, Ky, Caroline Adams Broderick

LSU Master's Theses

As water flows through areas of limestone, karst inevitably develops, creating sinking streams and sinkholes that transport alumino-silicate particles from the surface into the subsurface. Sediment budget studies on short term scales through karst are rare. Thus, a feasibility study using beryllium-7 (7Be), which attaches to soil particles and can be used as a short-term (2-3 month) tracer of the movement of fine-grained sediment in karst was investigated. Sediment samples were collected from a karstic catchment within Green River basin, Kentucky, both on the surface and in the subsurface along a cave stream. Samples were collected prior to and immediately …


A Composite Spatial Model Incorporating Groundwater Vulnerability And Environmental Disturbance To Guide Land Management, Johanna L. Kovarik Jan 2015

A Composite Spatial Model Incorporating Groundwater Vulnerability And Environmental Disturbance To Guide Land Management, Johanna L. Kovarik

USF Tampa Graduate Theses and Dissertations

Research has long recognized and studied the dynamics of groundwater processes. More recently, groundwater dependent ecosystems (GDEs) are being recognized for their diversity and vulnerability to anthropogenic impact. Groundwater in karst landscapes presents a distinctive situation where flow through the subsurface often moves rapidly on the scale of days and weeks as opposed to years or millennia in other systems. This distinctive situation of karst systems and their vulnerability to human impacts necessitate an integrated and multifaceted approach for the management of these important resources. However, development of such an approach is complicated by the difficulty of obtaining detailed data …