Physical Sciences and Mathematics Commons^™

Agricultural Irrigation Induced Evaporation In A Temperate Study Area: A Stable Isotope Approach, Lincoln Grevengoed

Masters Theses

In regions where groundwater is used for irrigation, significant water losses take place due to evaporation. Previous studies demonstrated the utility of stable oxygen and hydrogen isotopes in estimating evaporative water loss experienced during return flow back to an aquifer. Unlike arid regions where the other studies took place, this study examined the region around Kalamazoo, Michigan, the United States, which experiences a more temperate climate. Irrigation in the Kalamazoo area primarily uses center-pivot systems supplied by wells, unlike flood irrigation in previous study areas. Water samples were taken periodically from wells close to center-pivot irrigation systems. Water losses due …

Monitoring Salt Diapir Related Land Deformation And Distribution: A Geophysical And Remote Sensing Approach Jazan Province, Saudi Arabia, Hannah G. Pankratz

Dissertations

Salt diapirs are rarely preserved on the surface and seldom considered as environmental hazards. The Jazan city diapir (JZD) is located in southwest Saudi Arabia along the Red Sea coastal plain and outcrops in the middle of a rapidly growing port city. The intrusion of the diapir (~ 2 km²) into the overburden sediments continues to cause uneven surfaces, compromises building foundations and infrastructure, caused dissolution sinkholes, and limits the expansion of the city along the coastline. This research aims to better understand the distribution and deformation associated with salt diapirs in arid environments.

Using integrated Interferometric Synthetic …

Statistical Downscaling Techniques To Enhance The Spatial Resolution Of The Grace Satellite Data And To Fill Temporal Gaps, Hossein Sahour

Dissertations

The Gravity Recovery and Climate Experiment (GRACE) has been successfully used to monitor variations in terrestrial water storage (GRACE_TWS ) and groundwater storage (GRACE_GWS) across the globe, yet such applications are hindered on local scales by the limited spatial resolution of GRACE data. Using the Lower Peninsula of Michigan as a test site, I developed optimum procedures to downscale GRACE Release-06 monthly mascon solutions. A four-fold exercise is conducted. Cluster analysis is performed to identify the optimum number and distribution of clusters (areas) of contiguous pixels of similar geophysical signals (GRACE_TWS time series); three clusters are …

Integrating Detailed Petrography, Geochemistry, And Mineralogy To Elucidate Extensive Early Diagenesis In The Eocene Carbonates Of Qatar, Brooks H. Ryan

Dissertations

Eocene carbonates comprising the Umm er Radhuma (UER), Rus, and Dammam Formations, cover 80% of the surface and extend >300 m into the subsurface of Qatar. These rocks record marine sedimentation in shallow sub-tidal to restricted settings. Despite undergoing only shallow burial (<1000 m), extensive diagenetic alteration has occurred. Given that little work on this topic has been published previously, the objectives of this work are to document diagenesis in the Eocene, and to integrate petrography, mineralogy, and geochemistry to delineate the timing and environments of diagenesis of these Eocene carbonates. Detailed petrographic data show that dolomitization occurred early in the UER, before the formation of diagenetic chert, palygorskite, pyrite, calcite, and gypsum cements. Bulk dolomite δ¹⁸O values, coupled with clumped isotope-derived (Δ47) temperatures and dolomitizing fluid δ¹⁸O values, suggest dolomitization took place in near-normal marine fluids, perhaps during shallow burial. These data challenge the current paradigm of large-scale, top-down hypersaline reflux dolomitization in the UER. Associated depth trends of increasing crystal size and with increasing stoichiometry and cation ordering …

Field And Numerical Evaluation Of Nitrogen Transport From Septic Systems In Surfical Aquifer Systems To Charlotte Harbor, Florida, Tanten T. Buszka

Masters Theses

Shallow water tables in coastal surficial aquifers limit effective treatment of septic effluent which can result in excess nutrient loading into nearby surface water bodies. Approximately 45,000 septic systems in Charlotte County, Florida transmit effluent into an under studied surficial aquifer and contribute to harmful algal blooms and outbreaks of E. coli. An undeveloped field site was characterized using standard hydrogeologic methods, including a one-year duration natural gradient tracer test, to obtain representative lithology of the sandy surficial aquifer and estimates of groundwater velocity, flow directions, effective porosity and dispersion. These data were used to support the development of a …

Distribution And Variability In Sulfur Isotopes Within Paleoproterozoic Metasedimentary Strata Of The Michigamme Formation, Upper Peninsula, Michigan, Beau J. Haag

Masters Theses

In the Upper Peninsula of Michigan, the Paleoproterozoic Michigamme Formation is composed of a thick package of metasedimentary rocks derived from foreland basin sediments which were deposited during the 1.8Ga Penokean Orogeny. These rocks contain significant, but variable amounts of texturally distinct sulfide minerals such as pyrrhotite and pyrite. We report a systematic relationship between δ³⁴S values from sulfide mineral occurrences, and their stratigraphic locations regardless of texture and mineral composition. We suggest the sulfide minerals within the Michigamme Formation have inherited δ³⁴S values from early sedimentarydiagenetic sulfides, therefore preserving primary isotopic signatures. The observed stratigraphic …