Browsing by Subject "Limestone"
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Item Item Biological growth on the Alamo(2009-05) Gallagher, Casey Amber; Gale, Frances R.The limestone façade of the Alamo shows several areas of biological growth with black and gray streaks and blotches discoloring the stone. This thesis investigates the identity of the microorganisms on the stone, using two: DNA identification, and lab cultures grown from samples of the biofilm. By using both approaches, a better understanding was gained of the range of organisms present. Through these tests, it was found that the dominant organism on the limestone is cyanobacteria, of the genus Chrooccocus. Lab cultures revealed other organisms, including possibly fungi photobionts and algae. Through analysis and comparison of historic and contemporary photographs, patterns of recolonization are investigated. To further understand the effects of the biocide treatments, cultured samples were treated, and their reactions monitored. To better understand the possible relationship between the Alamo stone and its colonizing organisms, physical properties of the stone were investigated. SEM images, Edax minerology and water absorption were used to characterize the stone. This study is the first of its kind to investigate Native Texas quarried architectural limestone. Although studies have been conducted on historic monuments around the world to identify biological growth, none have focused on Texas limestone. By using both DNA and lab culture identification, this study adds to a wealth of investigations of other conservation professionals, applying it to a subject that has not been studied in this way before. By understanding the colonizing organisms, a sustainable conservation regimen can be determined.Item A conditions assessment and treatment recommendations for the main building at the Austin State Hospital(2011-12) Russell, Mary Kelley; Holleran, Michael; Gale, Frances R.This report addresses building envelope conditions of the Main Building of the Austin State Hospital (ASH), formerly the Texas Lunatic Asylum. Designed in 1857 to be constructed in phases and follow the nationally recognized Kirkbride plan, this four-story, solid limestone wall building remained a patient dormitory for almost a century. At present, the Main Building serves as the administration building for the ASH campus but has experienced deterioration due to inappropriate repairs and neglect as a result of inadequate funding. This report provides a historical record of the Main Building, documents existing exterior conditions, discusses mechanisms of deterioration for conditions and provides selected treatment recommendations. Observed conditions include biological growth, iron staining, limestone erosion, and inappropriate repairs with portland cement.Item Fold-related brittle structures and associated strain in a limestone bed of the Carmel Formation, San Rafael Swell, Utah(2015-12) Laciano, Peter Joseph; Marrett, Randall; Cloos, Mark; Ukar, EstibalitzThe San Rafael Swell (SRS) is a basement-cored Laramide uplift located in central-eastern Utah. The SRS is bounded on the east by a 70 km long monocline, a fault-propagation fold, with excellent exposure of sedimentary strata including the Carmel Formation. This monocline is an ideal natural laboratory for studying brittle deformation associated with folding. Qualitative and quantitative observations for brittle structures in a limestone bed near the base of the Carmel Fm. were made in a wide range of bedding dip, curvature, and fold domains. Kinematic data was collected for 2942 structures (1865 veins, 746 stylolites, 314 faults) in 30 locations in order to calculate principal directions of strain. Additionally, data was collected along 71 scanlines at 19 of those locations in order to estimate structure intensities and strain magnitudes. Dekameter-displacement thrust faults, acting as ramps between inferred layer-parallel faults, accommodate orders of magnitude more strain than all other observed brittle structures. These faults are only found in segments of the monocline where bedding dip is high, but curvature is low, which provides strong evidence that limb rotation more strongly controls strain magnitudes than layer bending in the SRS. The trishear model effectively predicts SRS monocline geometry, specifically observed limb thickening, broad, curved hinges, and progressively rotating limb. This is likely due to the dominance of thick, homogeneous rock packages, such as the Navajo Sandstone, in the SRS monocline. In contrast, strain localization within the Carmel Fm. is poorly predicted by trishear: there is strong evidence of flexural slip, and folding induced structure orientations and calculated principal strain directions remain consistent relative to bedding. These strain directions are inconsistent with trishear forward models produced by workers such as Zuluaga et al. (2014) that do not stay consistent relative to bedding. These divergences are likely due to the fact that trishear is a kinematic model that assumes rock homogeneity, while the Carmel Fm. is stratigraphically and mechanically heterogeneous. Because this heterogeneity appears to have a strong effect on strain localization, kink band models likely better estimate strain localization in the Carmel limestone bed as well as other layers in folded heterogeneous strata. The monocline’s interpreted transition from layer-parallel shortening to extension at the steepest locations in the monocline, and thus at most advanced stage of folding, enabled estimation of the dip of the basement fault beneath the SRS as ~30°. This shallow dip contrasts with the steep dip (~60°) assumed for the SRS by Zuluaga et al. (2014) and observed in the Kaibab uplift (Huntoon and Sears, 1975; Tindall, 2000), but is consistent with a recent estimation of 20-40° for the SRS by Davis and Bump (2009) using trishear modeling.Item The geology of the building stone of Cedar Park and vicinity(1922-06) Barrow, Leonidas Theodore; Bybee, Halbert Pleasant, 1888-1957Item Microbial community structure and nitrogen cycling in limestone biofilms(2015-08) Hancock, Tinisha; Brand, Jerry J. (Jerry Jay), 1941-; La Claire, John W; Leibold, Mathew A; Mehdy, Mona; Nobles, David RBiofilms inhabiting rock surfaces were of particular interest for this study, due to their ubiquity in central Texas and possible role in nitrogen cycling. Biofilm samples from an ornamental pond in Austin, Texas were collected over the course of two and a half years. Microscopic analysis indicated that the general physical structure of the biofilm remained constant, but the organisms inhabiting the biofilm varied. Metagenomic analysis confirmed that taxonomic diversity in biofilm communities is dynamic and variable, but the predicted functional capacities appear to be relatively stable throughout the sampling time. Less than one quarter of the variation in the taxonomic community data is explained by climate variables, indicating that a combination of stochastic and deterministic factors may drive community assembly. Limestone biofilm communities may be colonized from guilds of organisms that assemble based on the functional requirements prescribed by environmental conditions and resource availability. Natural biofilm samples were collected from other distinct patches of limestone in green spaces near Austin. Natural biofilms were thicker and more complex than the ornamental pond biofilms, yet they were not significantly different from each other in terms of their taxonomic community composition. The functional diversity of the natural biofilms was nearly identical to that seen in the ornamental pond biofilms. Taxonomic and functional diversity in natural biofilms were strongly correlated and significantly dissimilar. A strong negative correlation between actinobacteria abundance and bacteroidetes abundance was found, indicating that these organisms might be competitors. Cyanobacteria abundance was positively correlated with both humidity and precipitation, indicating that cyanobacteria might require more water than other organisms in the biofilm community. Organisms within limestone biofilm communities were capable of fixing atmospheric nitrogen, but the rate of nitrogenase activity was highly variable throughout the sampling period. Nostoc was the most abundant and active nitrogen-fixing organism. The abundance of cyanobacteria capable of fixing nitrogen was prone to fluctuation, whereas the abundance of non-photosynthetic nitrogen fixers remained relatively constant. Nitrogenase activity in the light reflects a combined effort between cyanobacterial and other nitrogen fixers and a consortium of other nitrogen fixers may be solely responsible for nitrogenase activity in the dark.Item Surfactant/polymer flood design for a hard brine limestone reservoir(2013-08) Pollock, Trevor Storm; Sharma, Mukul M.A limited number of laboratory studies and pilot programs have been reported in chemical Enhanced Oil Recovery (EOR) flooding of carbonate reservoirs (Adams & Schievelbein, 1987). Fewer still have involved surfactants in limestone reservoirs. No surfactant/polymer flood on a field wide basis of a carbonate reservoir has ever been documented in the literature (Manrique, Muci, & Gurfinkel, 2010). This void represents a colossal opportunity given that nearly a third of the 32 billion barrels of oil consumed in the world each year come from carbonate reservoirs (Sheng, 2011, pp. 1, 254). This thesis is based on experiments with a high hardness (~5,000 ppm divalent ions) carbonate field. Phase behavior, aqueous stability, and core flood experiments were performed using polymer and various surfactants and co-solvents. Both commercially available and laboratory synthesized surfactants were tested. The objective was to optimize the chemical injection design in order to lower interfacial tension between water and oil in the reservoir. Research was also done with alkali intended for use with hard brines. The main challenges when working with hard brine were poor solubilization and low aqueous stability limits. However, highly propoxylated and ethoxylated surfactants mixed with internal olefin sulfonates, hydrophilic sulfates, and sec-butanol were observed to have very high solubilization ratios, fast phase behavior equilibration times, negligible viscous macroemulsion effects, and excellent aqueous stability. Spinning drop interfacial tensiometer tests confirmed low IFT values were obtained for a range of acceptable salinities with hard brine. Three core floods were performed using one of the surfactant formulations developed. One flood was done with field core, brine, and crude oil and failed to meet expectations because of high levels of heterogeneity (vugs) within the core that lead to an elongated oil bank and low and slow oil recovery. The other floods were done with Estillades Limestone. The first Estillades flood used hard synthetic field brine and had better mobility but poor oil recovery. The last core flood had good mobility and recovered 90% of the residual oil to water flooding, but only after a total of 1.1 pore volumes of 1.0 wt% surfactant solution were injected. The results provided in this thesis constitute proof of concept that S/P flooding can be done in high salinity and hardness reservoirs.Item The sediments of the Madera Limestone, New Mexico(Texas Tech University, 1950-05) Hasson, Richard C.NOT AVAILABLE