Growth and dissolution of the mineral calcite is important for prediction and control of surface and subsurface water quality, calculation of past sea-surface temperatures using paleoenvironmental proxies, and sequestration of contaminants through engineered calcite precipitation. At high concentrations of strontium, calcite growth is known to be inhibited, but the mechanism by which strontium inhibits growth is not well understood. Seeking to better understand this mechanism, atomic force microscopy is used with a flow-through fluid cell to measure real time growth rates of the obtuse and acute monomolecular step orientations on the calcite surface. Growth was measured at two saturation indices as a function of the ratio of the concentrations of aqueous calcium-to-carbonate and varying aqueous strontium concentration. It was found that the amount of strontium required to inhibit growth correlated with the aqueous calcium concentration, but did not correlate with carbonate concentration. This suggests that strontium inhibits attachment of calcium, but not carbonate, during growth. Analytical models of nucleation and propagation of steps are expanded from previous studies to capture multiple saturation indices.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (p. 166-172).

The Big Clifty is a Chesterian-age Mississippian sandstone member of the Golconda Formation that extends from south-central Kentucky into adjacent Illinois and Indiana. Asphaltic deposits and conventional petroleum plays are distributed along the Pennyrile Fault System and Plateau in the southeastern portion of the Illinois basin. In south-central Kentucky anomalous oil-saturation geometries are observed in cored sections of the Big Clifty from wells in Warren and Butler counties along the margin of the Pennyrile Plateau. Petrographic study of the cores has revealed several diagenetic processes that have contributed to, or are directly responsible for, the anomalous oil saturation geometries and resultant reservoir partitioning. This study utilizes standard transmitted and reflected light microscopy, UVepifluorescence, optical cold-cathode cathodoluminescence microscopy, scanning electron microscopy, and alizarin red S and potassium ferricyanide staining in petrographic examination. Raman microscopy, energy-dispersive X-ray spectroscopy, transmitted electron microscopy, and X-ray diffraction assisted in identification and compositional analysis of minerals. Quantification of framework grains and cement compositions, porosity, and grain-size distributions was also conducted. This study’s data classified the Big Clifty as a fine to very-fine grained, quartz arenite with predominantly silicious and phyllosilicate cements and a mean of porosity of 7%. Oil-saturation geometries concordant to rock fabric are due to compaction, weathering of labile grains, and precipitation of authigenic cements (mainly quartz, kaolinite, and pyrite). A paragenetic sequence, established from textural evidence, places quartz, kaolinite, and pyrite phases early in paragenesis with labile grain dissolution, compaction, and precipitation of ferroan carbonate cement, with development of vugular porosity occuring later during burial. These phases and processes enhanced preexisting porosity and permeability heterogeneities within the rock. Nodular pyrite, oil emplacement, and precipitation of poikilotopic calcite are the latest diagenetic events. Nodular pyrite and poikilotopic calcite are responsible for oil-saturation geometries distinctly discordant with rock fabric. Poikilotopic calcite forms interstratal seals, occluding porosity, replacing framework grains and cements, and overprinting primary rock fabric. This study’s preliminary research into the poikiloptopic calcite suggests its occurrence is possibly associated with the cored wells’ shallow depths less than 500 feet (150 meters), and proximity to near-vertical faults and waters from drainage systems of karstified carbonate aquifers updip.

Thesis (Ph. D.)--University of Michigan, 1938. / Cover title. "Reprinted from the Physical review, vol. 54, no. 12, December 15, 1938."

No description available.

Thesis (Ph. D.)--University of Michigan, 1938. / Cover title. "Reprinted from the Physical review, vol. 54, no. 12, December 15, 1938."

The theory of the Raman Effect in crystals has been re-examined by O. Theimer (Can. J. Phys. 1956, 34 312) in an attempt to overcome some discrepancies between experimental results and predictions of the theory. New selection rules have been derived by investigating the validity of the assumptions made in the earlier theory. The new theory, applied to the symmetric Raman line of Calcite, predicts that, for the crystal orientated with its optic axis parallel to the illuminated surface, the "forbidden" component will be truly forbidden for forward or backward scattering, while appearing as previously reported for scattering at 90°. The present investigation is concerned with measuring the relative intensities of the polarized components of this line for backward scattering, the measurements being made with the crystal orientated with its optic axis either parallel or perpendicular to the illuminated surface. A method for increasing the scattering volume by joining several crystals along cleavage faces has been developed and a new mercury discharge lamp was designed which gave an appreciable increase of the illumination intensity. The relative intensities of the components of the symmetric Raman line obtained were evaluated by careful consideration of the characteristics of the photographic emulsion used to record them. The results tend to confirm the predictions of the new theory. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Clumped isotope paleothermometry defines carbonate formation temperature based upon the relative abundance of the 13C18O16O isotopologue within CO2 (Δ47) formed through phosphoric acid digestion of carbonates. When precipitated in equilibrium, resultant Δ47 values are inversely-proportional to growth temperature, where 13C18O16O is more abundant at lower temperatures. To precisely define Δ47 values, a rigorous analytical protocol is required to: (1) minimize CO2-H2O isotope exchange during acid digestion; (2) purify CO2 to remove contaminants; (3) quantify the raw Δ47 value using a mass spectrometer configured for m/z 44 – 49; and (4) normalize the raw Δ47 value to account for machine-specific isotopic scrambling and Δ47 vs. δ47 non-linearity. Amongst laboratories with well-established analytical protocols, substantial disagreement still exists between proposed clumped isotope calibrations at low temperatures. To investigate the source of this discrepancy, calcite was precipitated between 15 – 40 °C from a HCO3-(aq)-dominated solution using an upgraded constant addition technique. This technique is the first to provide simultaneous control of δ18OH2O and δ13CDIC values of parent solution. Observed oxygen isotope fractionation between calcite and water is in agreement with Kim and O’Neil (1997), providing robust evidence of calcite precipitation in oxygen isotope equilibrium. Δ47 values were determined using McMaster’s clumped isotope facility, yielding the following calibration: Δ47-RF = 0.0351 (± 0.0021) × 106/T2 + 0.2982 (± 0.0233) This calibration observes a similar temperature dependency to theoretical models as well as ‘shallow’ slope experimental studies. To provide context to experimental calibrations with ‘steep’ slopes, we consider the non-equilibrium isotope effects of CO2 hydration/hydroxylation and HCO3- dehydration/dehydroxylation reactions on precipitating calcite. We propose that low temperature calcites primarily responsible for the ‘steep’ slopes of certain calibrations have partially inherited the disequilibrium isotope composition of DIC due to significant non-equilibrium isotope effects associated with the aforementioned CO2 hydration/hydroxylation and HCO3- dehydration/dehydroxylation reactions. / Thesis / Master of Science (MSc)

Thesis (M.S.) -- Mississippi State University. Department of Geosciences. / Title from title screen. Includes bibliographical references.

The St. Lawrence Platform is located along the northern shoreline of Lake Ontario, currently in an intra-cratonic setting exposing relatively flat-lying middle Ordovician sedimentary strata. The purpose of this study is to gain insight on recent brittle deformation events that have deformed the bedrock. Based on structural field observations, broadly trending E-W extensional joints are the youngest stress recorded in the bedrock. These joints are partially filled and sealed with calcite mineralization and were strategically sampled to gain insight on the source and timing of fluid flow. Trace element geochemistry and stable isotope (δ18O and δ13C) analysis on calcite mineralization indicate that their compositions are analogous to the host rock, thus, fluids originate from connate fluids that were released from pore space during deformation. In addition, U-Pb geochronology via LA-ICP-MS methods yield a model age of 101 ± 6 Ma (MSWD: 2.3). The date of calcite crystallization is contemporaneous with the establishment of North America’s modern compressive stress field, and is linked to a Cretaceous tectonic plate reorganization event that was global in scale. This study demonstrates that calcite veins can serve as a tool to date brittle deformation in limestone, which could have direct applications in hydrocarbon exploration, paleohydrology, and the consideration for locating sites to host deep geological repositories.