The mineralogic associations of arsenic (As) and antimony (Sb) were investigated for the Avon Park Formation (APF) in central Florida to determine its viability for aquifer storage and recovery (ASR). Rock samples were taken from fourteen different cores and samples were taken according to core length, interval samples, and based on areas suspected to contain high levels of arsenic and antimony, such as molds, dissolution fractures, pyrite, clays, and organic matter, targeted samples. Permeable samples were also taken from high permeability zones. In total 373 samples were described in hand specimen and analyzed for bulk rock chemistry. Inductively coupled plasma optical emission spectrometry and hydride generation atomic fluorescence spectrometry were used to determine Fe, Al, Si, Mg, Ca, S, P, Mn, Sr, Mo, As, and Sb in bulk samples, while electron-probe microanalysis was used to analyze Sb, As, Fe, S, Zn, Ca, Mo in discrete minerals. The mineralogic and geochemical investigation showed: (1) bulk As and Sb concentrations within the APF are low; (2) As values range from < 0 .1 to 30.8 mg/kg and Sb from < 0.1 to 6.76 mg/kg; (3) average values are 2.24 mg/kg As and 0.28 mg/kg Sb; (4) pyrite is present as framboids, hollow framboid rings, "honeycomb" pseudo-framboids, small irregularly shaped pieces with topography, and euhedral crystals; it is typically associated with oxidized organic laminations, fractures, and molds; (5) the framboid rings may have been precipitated by a bacteria making them biogenic; (6) euhedral pyrites contain significantly less As than other morphologies while irregular pyrites have the most; (7) individual pyrites range from < 0.1 to 5820 mg/kg As while Sb ranges from < 0.1 to 2470 mg/kg; (8) the samples from zones of high permeability have lower As and Sb averages than those of the other samples: 1.02 mg/kg As and 0.15 mg/kg Sb versus 1.32 mg/kg As and 0.19 mg/kg Sb for interval and 3.16 mg/kg As and 0.37 mg/kg Sb for targeted samples; (9) As is found mainly in pyrite but is possibly from organic matter and clay; (10) overall As concentrations and correlations may be low but individual cores and zones have high values; (11) the APF has appropriately permeable zones for ASR; (12) the success of ASR in the APF formation depends on the degree of geochemical alterations, presence of competing anions and simple organic ligands, and the amount of trace metals sorbed to surfaces versus coprecipitated.

This work presents new method for determination of geological provenance based on the statistical analysis of cathodoluminescence spectra of marbles and carbonate rocks from various localities in the Bohemian Massif. Analysis is based on the combination of data from seven different measures of spectral similarity and provides results that are more robust than those obtained by approach based only on a single measure of similarity. These results may be further improved by employing meta-analysis that evaluates behaviour of spectra during the individual steps of analysis. Analysis was performed on the original cathodoluminescence spectra, as well as on the residual spectra in which relative variability was amplified by the subtraction of Gaussian trend present in all spectra of carbonates. By combining results from analysis and meta-analysis of both original and residual spectra it was possible to almost unambiguously determine provenance of samples from all studied localities. Agglomerative hierarchical clustering was employed as a supplementary method for classification of spectra. Out of 72 different methods for clustering, one was selected for both original and residual data based on the number of correctly classified spectra. Second part of this work presents analysis of cathodoluminescence...

The presented work is focused on research of distribution of trace elements in carbonate sediments and fossils in the Bohemian Cretaceous Basin. To obtain maximum information about the composition of the primary carbonate and its crystallization environment, the trace elements were analyzed mainly in fractions soluble in diluted acid. Another objective is the comparison of trace-element abundance in the soluble fraction and in the residue (or in the total mass of the samples). The results show that there are no systematic differences in the chemical composition of the original carbonate between various regions and stratigraphic positions (Cenomanian - upper Turonian). Elements like Sr, Mg and Mn in carbonate were affected by diagenesis, but contents and mutual ratios of the rare earth elements in all carbonates are similar and are characterized by negative cerium anomaly. The Ce-anomaly could be attenuated by elevated content of clastic matter, and in the soluble portions ocassionally via contamination by secondary phosphate. On the other hand, soluble fractions of limonite-rich and calcite-poor sandstones have positive cerium anomaly, which is the effect of Ce-sorbtion on limonite.

Sediment on Cay Sal Bank (CSB) is characterized by its coarse-grain size, poor sorting, predominance of skeletal fragments, and relatively depleted d18O isotope values. CSB is an incipiently drowned platform in close proximity to the Great Bahama Bank (GBB), a carbonate platform which is not incipiently drowned and characterized by fine-grained, non-skeletal sediment. The GBB has locally well-developed oolitic grainstone facies and coral reef margins, which are both lacking on CSB. Platform-top water depths on the GBB are typically 10 m or less, but CSB depth ranges between 7 and 30 m. CSB is devoid of mud, whereas mud-supported depositional texture on GBB comprises 28% of the dataset. Dominant non-skeletal grains are grapestones and pelletoids, and the latter display evidence of micritization. Non-skeletal types on GBB are primarily grapestones and ooids. Surficial sediments from both platforms are primarily composed of aragonite, but high-magnesium calcite is slightly more prevalent on CSB. Similar to other incipiently drowned platforms in the Caribbean, CSB has been subject to rapid Holocene flooding. Common features between these three platforms are a thin sedimentary cover, a dominance of Halimeda plates, and micritized cryptocrystalline grains. Increased nutrient levels have been shown to be related to platform drowning as well as the reduction of coral and algal growth on Serranilla Bank, but rapid Holocene flooding has been more likely for CSB, and appears to be in the second of a three-stage drowning process, ultimately culminating in carbonate platform “turn off”, preventing further carbonate and reef development at the level of GBB.

No description available.

The exposed Tertiary carbonates of the Dammam Dome present an opportunity to study fractures in outcrops within the oil-producing region of Eastern Saudi Arabia. The study focuses on: 1) the characterization of fractures, 2) interpretation of their fracturing mechanism, and 3) the implications for the deep carbonate reservoirs of the Dammam Dome. The characterization of the outcrop fractures is integrated with structural analysis of the near-surface horizons mapped from reflection seismic and well data. Fractures are observed within all exposed carbonate units, but predominantly within the widely exposed Middle Rus unit. The fractures are opening-mode, bed-bound joints that form orthogonal sets (NW-SE and NE-SW trending joints). The trends of through-going, primary NW-SE trending joints do not correlate with the trends of remote regional stress associated with compression of Zagros uplift, suggesting they did not develop due to that orogenic event. The primary joints also seem to have developed independently of the observed karst features and interpreted near-surface faults. The analysis of joint pattern and their spacings generally seem to reflect the fold growth of the strata, position on fold and mechanical stratigraphy. The study results provide a first-order conceptual fracture model for the subsurface reservoirs to guide future development.

The Early Pennsylvanian (Bashkirian/Morrowan) Round Valley Limestone of northeastern Utah was deposited on the Wyoming shelf, a slowly subsiding depositional surface located between the Eagle and Oquirrh basins. The 311-foot-thick Round Valley Limestone displays a distinct cyclicity formed by stacked, meter-scale parasequences, comprised of a limited suite of open- to restricted-marine limestones with minor interbeds of siltstone and shale. Open-marine deposits are characterized by mudstone and heterozoan wackestone-packstone microfacies (MF1-4) and comprise the lower portions of parasequences. Rocks of these microfacies were deposited during maximum high-order transgression of the shelf. As sediment filled the limited accommodation, the shelf became restricted, leading to deposition of mollusk-peloid dominated wackestone microfacies (MF6). Grainstones (MF5) microfacies are volumetrically limited in the Round Valley and represent deposition on isolated sand shoals that populated the shallow shelf. The complete Round Valley section at Split Mountain in Dinosaur National Monument is comprised of 5 intermediate-order sequences and 48 higher-order parasquences. Twenty-one of the shallowing-upward cycles are bounded by exposure surfaces as indicated by the occurrence of rhizoliths, glaebules, autobreccia and alveolar structures. Four of these that also indicate a significant drop in sea level (abnormal subaerial exposure surfaces and surfaces with erosional relief) constitute candidate sequence boundaries. The high percentage of cycles capped by exposure surfaces indicates that deposition of the Round Valley took place intermittently and that the Wyoming shelf was exposed during a significant portion of the Bashkirian epoch. Intermittency of deposition is confirmed by comparing the thickness and sequence architecture of the Round Valley Limestone with coeval strata in the eastern Oquirrh basin (Bridal Veil Limestone). The Bridal Veil Limestone is four times thicker and contains 24 cycles not represented on the Wyoming shelf.

<p> The transition from the Whirlpool Sandstone to the Manitoulin Dolomite represents a marine transgression. Within the Manitoulin Formation, the proportion of siliclastics to carbonates shows a marked upward decrease. The Manitoulin Formation consists of four main facies. The lower two facies indicate an inner shelf environment, while the upper two represent a middle to outer shelf environment. </p> <p> These sediments have been almost totally dolomitized. Cathodoluminescent microscopy was employed to determine the diagenetic history of quartz, calcite, and dolomite cements. The petrographic characteristics of the dolomite using CL and normal light indicate a late stage (epigenetic) dolomitization. </p> <p> Dolomitization is thought to have been a late diagenetic process brought about by Mg-rich fluids expelled during compaction of adjacent shales and supplemented by brines circulating through fracture systems. </p> / Thesis / Bachelor of Arts (BA)

No description available.

No description available.