Diagenesis and sequence stratigraphy have been formally treated as two separate disciplines in sedimentary petrology. This thesis demonstrates that synergy between these two subjects can be used to constrain evolution of reservoir quality in sandstones. Such integrated approach is possible because sequence stratigraphy provides useful information on parameters such as pore water chemistry, residence time of sediments under certain geochemistry conditions, and detrital composition, which ultimately control diagenesis of sandstones. Evidence from five case studies and from literature, enabled the development of a conceptual model for the spatial and temporal distribution of diagenetic alterations and related evolution of reservoir quality in sandstones deposited in paralic environments. Diagenetic alterations that have been constrained within the context of sequence stratigraphy include: (i) formation of kaolinite and intragranular porosity, and mechanical infiltration of clay minerals in sandstones lying at variable depths below sequence boundaries, (ii) formation of pseudomatrix and cementation by calcite, dolomite, and siderite in lag deposits at parasequence boundaries, (iii) cementation by kaolinite, pyrite, and calcite in sandstones lying in the vicinity of parasequence boundaries with coal deposits, (iv) formation of glaucony in condensed interval at parasequence boundaries, transgressive and maximum flooding surfaces, (v) formation of berthierine in fluvial-dominated deltaic deposits of the highstand systems tract, (vi) cementation by calcite in bioclastic sandstones of the transgressive systems tract, and (vii) formation of kaolinite in fluvial deposits of the lowstand systems tract. The distribution of such alterations put important constrains for the pattern of burial diagenesis (e.g., formation of chlorite, illite, quartz), related evolution of reservoir quality in sandstones, and distribution of baffles and barriers for fluid flow in the context of sequence stratigraphy.

Field studies encounter several complicating factors not studied in the models. Examples are oblique convergence, heterogeneous materials and thermal softening by intruding magmas. Within the deeply eroded Svecokarelian orogeny, studies in eastern Bergslagen indicate strain accommodation of the N-S orogenic shortening by regional E-W folding and shear along the conjugate Singö Shear Zone and Ornö Banded Series. Rising temperature resulted in migmatites affecting the strain accommodation resulting in decoupling and rotation of folds along one of the deformation zones. Deformation zones developed in convergent orogens have been studied in both analogue models and in nature. These studies have focused on a number of important factors controlling strain accommodation during orogenesis. The models show that the shape of the leading edge of the indenting continent controls whether the initial suture remains active or if an effective indenter develops, the spacing and number of faults, the width of the orogen and the height of the mountains. All these characteristics depend on the rate and spatial distribution of erosion and sedimentation. Erosion decreases the importance of effective indenters and favors shearing on existing faults leading to steeper, longer lived shears bounding narrow orogens. If sediments load the margin (e.g. foreland), the thrusts propagate further outboard widening the orogen. The strain that is accommodated by compaction and shearing along deep décollement and conjugate imbricate shears is episodic in time. This work links episodes of increased rates of erosion and sedimentation to episodes of high uplift rates, i.e. the development of new imbricate thrusts or pop-up wedges.

The Forsmark Nuclear Plant is one of the largest in Sweden and produces around one sixth of the total electrical energy in the country. It is situated on the east coast of Sweden in the Uppland region. Nuclear waste has to be properly handled every year and Forsmark is one site proposed for long-term storage of all spent fuel from Swedish nuclear power reactors. This potential high-level repository (a low-level one already exists in the area) will be based on the KBS-3 design process, which consists of 6000 iron-copper capsules where the waste will be stored for 30 years and finally buried 500 m down, isolated from the environment for100.000 years. Before using the disposal site, numerous investigations must be done in the area so the risks are reduced as much as possible. These investigations include drilling of cored boreholes down to 1000 m depth. In this study the KFM01A borehole (figure 1.1) was used with different shot points to analyze possible anisotropy in the subsurface. The anisotropy in rocks can be due to different mechanisms as crystal and mineral grain alignment, crack and pore space alignment and thin layer anisotropy (Rowlands J. et al., 1993). For this purpose a shear wave splitting analysis was done in an attempt to determine both orientation and density of fractures. Shear wave splitting has shown to be a very effective method detecting fractures, providing an unique ability to measure anisotropic seismic attributes that are sensitive to fractures (James E. Gaiser, 2004). This can be useful in many domains as in oil companies to improve reservoir management (James E. Gaiser, 2004) or as an imaging tool in fracture-controlled geothermal reservoirs, to monitor fluid pressure in the cracks and changes in crack density (Tang Chuanhai, 2005). Shear wave splitting studies have also been done in seismology for crustal studies (Rowlands J. et al., 1993). When shear waves enter anisotropic medias they split in two approximately orthogonal components, where the faster and slower components will travel parallel and perpendicular to the fracture planes respectively. The time delay will depend of the amount of anisotropy and the path length. Different methods can be used to evaluate the anisotropy; polarization diagrams (Crampin et al., 1986), linear moveout plots of the horizontal components (Li et al.,1988).The procedure described by Li et al. (1988) are the techniques that are used in the present study. The fractures orientation is also analyzed and compared with the general stress components in the area using well bore information from previous studies, as well as the general tectonic characteristics of the zone.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 117-130). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 117-130). Also available on the Internet.

<p>The Grenville Province is alGa orogenic belt, composed of much older terranes whose age and extent require mapping in order to gain a better understanding of its geological evolution. Manicouagan, Quebec, in the Grenville Province, has experienced several orogenic events, as well as being the site of a 214 Ma hypervelocity impact event, which has further complicated its geological structure. By analyzing surface samples from this area, as well as driB core of the country rocks involved in the impact, the original age of crustal formation for the various terranes can be calculated, thus revealing the evolutionary history of the Manicouagan area.</p> <p>Nd isotopes are resistant to metamorphic disturbances, therefore permitting accurate calculations of original crustal formation ages. Nd-isotopic analysis of granitoid orthogneisses, has identified three major crustal formation age groups in the area. These are: Mesoproterozoic (1.58 Ga), Paleoproterozoic (1.86 Ga), and Archean (2.8 Ga). These average depleted mantle model ages (TOM) correspond well with isochron reference lines, supporting their validity as actual geologic events.</p> <p>The spatial distribution of age data results indicate that the Archean basement extends farther south on the western side of the Manicouagan reservoir than previously thought, whereas the eastern side is dominated by Paleoproterozoic crust. In contrast, the Manicouagan Imbricate Zone (MIZ), located between the Archean and Paleoproterozoic crustal terranes, as a wider scatter of Nd data attributed to mixing between Archean and Proterozoic sources. This crustal terrane has been limited to within the interior of the reservoir in the south, and extends just north of the reservoir. The location of the boundary between the Archean and Paleoproterozoic terranes, the Allochthon Boundary Thrust (ABT), was largely agreed upon to the east and west of the impact, but its position was highly ambiguous near the impact itself. New Nd analysis shows that this boundary crosses onto the island on the NW side of the reservoir, and exits to the west of the previously established Cryptic Shear Zone (CSZ) at the southern end of the impact. The boundaries of these distinctive crustal terranes are further supported through aeromagnetic evidence.</p> <p>The 214 Ma hypervelocity event resulted in the instantaneous melting of target rocks located beneath the impact. Isotopic and elemental geochemistry was employed to characterize the composition of the meltsheet. These data show that the melt sheet was largely derived from the MIZ, but cannot rule out a small component of underlying Archean crust. Further isotopic, trace element and major elemental analyses are needed in order to fully decipher the target rock composition.</p> / Master of Science (MS)

<p>Geochronological study of the Grenville Province has been an ongoing project at McMaster for the past 20 years. Over 1,500 orthogenesis samples have been collected from a 700,000 square kilometer region, and geochemically analyzed for Neodymium model ages. This vast area has been subjected to multiple accretion and ductile deformation episodes, creating great geological complexity.</p> <p>The two mam belts of the Grenville Province are the Allochthonous Belt, consisting of terranes which were laterally transported by the Grenville orogeny, and the underlying Parautochthonous Belt. The boundary separating these two major belts is termed the Allochthon Boundary Thrust (ABT) and represents the northwesterly limit of major crustal movement during the Grenville orogeny. Due to the high degree of exhumation of mid to lower crustal levels, identification of the ABT is difficult within Southwestern Ontario. As a result, lithological maps, such as the Geological Survey of Canada (GSC) map of the Grenville Province created by Davidson (1998), do not correctly identify sections of the ABT. In addition, impOliant geological features such as structural outliers (klippen) of the Allochthonous belt are not correctly identified. Along much of its length the ABT defines the boundary between Archean- Paleoproterozoic (> 1.8 Ga) and the Paleo- Mesoproterozoic «1.8 Ga) crust. Therefore, by measuring the isotopic composition of either side of the ABT the boundary can be clearly defined.</p> <p>Previously collected Nd isotope data were plotted on ESRI's Geographical Information System (GIS) and digitally represented. Interpolation based on sample age distribution was conducted to assess completeness of the data set. Interpolation techniques included triangulated irregular networks, inverse distance weighting, and kriging, which were used to obtain global and localized trends. This approach highlighted discrepancies between geological and geospatial interpretation, therefore highlighting areas which needed additional sampling.</p> <p>Nd-model analysis of olihogneiss from four areas collected within Northeastern Ontario and Southwestern Quebec have provided additional information to this interpolation process. Through the addition of these samples the boundaries of the ABT and klippen have become much more precise. Digital mapping of the terranes of the Grenville Province through integration of the aforementioned techniques has provided an improved understanding to the geological history of the Grenville Orogeny.</p> / Master of Science (MS)

<p>By studying signatures of life within extreme environments on Earth we better understand signatures of life that may be found within the geologic record on Earth as well as elsewhere in the universe. This thesis research utilized phospholipid fatty acid analysis (PLFA) in combination with carbon isotopic analysis (δ¹³C) to understand microbial carbon cycling and biosignatures within two Mars analogue environments.</p> <p>The Golden Deposit was an acid sulfate environment that was an analogue to the acid-sulfate conditions present on early Mars. Mixing of inflowing surface water and upwelling acidic groundwater on the deposit caused variations in water chemistry. Such variations resulted in differences in the microbial communities and carbon isotopic compositions within the Golden Deposit. The most acidic groundwater seep on the deposit had a distinct geochemistry, which selected for a unique microbial community and distinct carbon isotopic signatures. Variations detected within the small spatial area of the Golden Deposit indicated that biosignatures preserved on Mars might be highly variable making the unambiguous identification of past life on the planet more difficult.</p> <p>Three saline lakes of the Cariboo Plateau were used for this study and were analogues to environmental conditions present on early Earth as well as the alkaline, evaporitic conditions present on early Mars. All three lakes contained benthic microbial mat communities dominated by cyanobacteria. Photosynthetic influences by cyanobacteria resulted in an isotopic enrichment of the DIC pool. Enriched lake DIC values were preserved in precipitated carbonates (δ¹³C_carb) and the ∆¹³C_DIC-TOC(avg) was similarly preserved in ∆¹³C_carb-TOCvalues and were biosignatures of photosynthetic activity. The preservation of these biosignatures suggested that concentrations of CO₂ on early Earth did not necessarily exceed modern levels and that measuring the carbon isotopic compositions of carbon pools within saline, carbonate-rich deposits on Mars could lead to the identification of past life on the planet.</p> / Master of Science (MS)

<p>This thesis examines psychosocial effects in a population living near the Halton Regional Landfill site in Milton, Ontario. The data described and analyzed in this research were collected between 1990 and 1995 and capture key events in the landfill site's history--site approval, construction and operation. This longitudinal study, which examines indicators of stress, reappraisal and coping at three different points in time from the same individuals, is designed to document and examine the process whereby these people have experienced and come to live with the landfill facility over time. The theoretical basis for understanding this process of appraisal, reappraisal and coping is derived from environmental stress and coping theory generally, and from the framework proposed by Lazarus and Folkman (1984) specifically. Three research objectives are addressed: (1) to document changes in psychosocial effects in Milton area residents between 1990 and 1995; (2) to explore the processes of reappraisal and coping among Milton area residents; and, (3) to evaluate the appropriateness and usefulness of the Lazarus and Folkman (1984) framework in the context of a population living proximate to a solid waste facility. These objectives are addressed through three administrations of a telephone survey instrument comprised of a combination of pre-validated scales and open- and closed-ended items to a random stratified (by distance) sample of households immediately after the landfill site was approved (1990), shortly after the site was constructed and began operation (1992-3), and two years after operation had begun (1995). Due to attrition, the baseline cohort (n = 187) was reduced to 108 by time 3, although no significant bias was introduced. Data from all three surveys were obtained for a sub-group of 87 respondents. Five constructs derived from environmental stress and coping theory guide the examination of individual responses to the landfill over time: psychological distress, perceptions of the landfill site, concerns about the landfill site, actions and neighbourhood satisfaction. A series of hypotheses, which capture expectations about how Milton area residents have experienced the introduction of the landfill site into their community over time, were generated from the constructs and guide the analysis. Overall, the results portray a community that has changed from one actively opposing plans to locate a landfill site in its midst to one that has, for the most part, resigned itself to and accepted the presence of the new facility. (Abstract shortened by UMI.)</p> / Doctor of Philosophy (PhD)

<p>This study is concerned with speciation and fractionation of the rare earth elements (REE) and calcium (Ca) in aqueous solutions. The aim is to investigate the chemical states and physical sizes in which these elements can be present. The REE (including neodymium) and Ca have contrasting geochemical behavior in aqueous solutions. Ca is a major dissolved element, while the REE are trace components and highly reactive with aquatic particles.</p><p>The major interests of the five papers included in this thesis are the following:</p><p>· Papers I and V deal with the behavior of neodymium (Nd) and its isotopes in the Kalix River and some marine waters.</p><p>· The diffusive gradients in thin-films (DGT) method is developed for measuring Ca and Mg in Paper II.</p><p>· Paper III presents a speciation and fractionation study of Ca in the Kalix and Amazonian rivers.</p><p>· The rare earth elements and their carrier phases are investigated in the Kalix river in Paper IV.</p><p>For most elements a detailed study of speciation and fractionation can not be performed using only one method. This is due to the overall heterogeneity of the material, considering both size and chemical composition, which is present in aquatic solutions. During this project the aquatic geochemistry of the REE and Ca has been studied using mainly three methods; cross-flow filtration (CFF), field-flow fractionation (FFF) and diffusive gradients in thin-films (DGT). Field work has to a large part been conducted in the Kalix River, in northern Sweden, which is one of the last pristine river systems in Europe. Some field work has also been conducted in the Baltic Sea and the Arctic Ocean. Results from Amazonian rivers are also presented.</p><p>These are the main conclusions from this work:</p><p>The DGT technique works equally well for measuring Ca and Mg in natural waters as previously reported for trace metal.</p><p>A significant colloidal phase for Ca could be detected in the Kalix River and in different Amazonian rivers. This was concluded independently using both CFF and FFF.</p><p>Variations in REE signatures in the Kalix River suggests two different pathways for the REE during weathering and release form soil profiles and transport in the river.</p><p>No significant variation in Nd-isotopic composition could be detected in the Kalix River although concentrations varied by a factor of ~10. This suggests that there is one major source for Nd in the river although different pathways for the REE may exist.</p><p>A study of Nd in the Kalix River, the Baltic Sea and the Arctic Ocean showed that the isotopic compositions in the diffusible fractions were similar to water samples. However, the relative amount of diffusible Nd increased with salinity, probably reflecting the lower concentration of colloidal and particulate material in marine waters.</p>