The Middle and Upper Devonian (Givetian-Frasnian) shallow-water carbonate facies of western Europe were deposited as a large-scale transgressive succession over continental facies of the Old Red Continent. The transgression was in a northerly direction, reaching the southern Ardennes by the lower Eifelian and the Aachen area of Germany by the middle Givetian. Carbonate sedimentation continued through to the middle Frasnian, when a major pulse m relative sea-level rise drowned the platform. The carbonate platform had a complex internal structure, with three major palaeosettings. During the Eifelian, a storm-influenced homoclinal ramp existed over much of the Ardennes. Sedimentation was mostly open-marine in nature, with a protected back-ramp and tidal-Oats. The Givetian saw a transition from a ramp to shelf setting, with stromatoporoid reefs at the shelf edge providing protection for abroad shelf lagoon. The shelf had an ESE-WNW trend and extended from Boulogne (northern France) in the west to Aachen (western Germany) in the east. East of the river Rhine in the Rheinisches Schiefergebirge area of Germany, and in Southwest England, isolated carbonate complexes developed. These were positioned either on the shelf-edge, within the shelf or upon topographic highs within the basin. Synsedimentary tectonism and volcanism strongly influenced their development. As a result of their areal extent, lagoonal environments were studied extensively in shelf and isolated complexes. Palaeontology and sedimentology were used to identify 14 major microfacies within the lagoonal successions, which could be broadly categorised into four major groups. The semi-restricted subtidal microfacies group has a rich faunal assemblage which, although diverse, did not represent fully open-marine deposition. Sedimentation was entirely subtidal in nature. The restricted subtidal microfacies group is either characterised by monospecific fossil assemblages (chiefly molluscs or amphiporoids), or by macrofossil-poor facies. These facies represent poorly-circulated, subtidal environments which may have been subjected to flucmating salinities The intertidal microfacies group is characterised by fenestral limestones, which are commonly poorly-fossiliferous. Finally the supratidal microfacies group is typified by dolomudstones, microbial laminites and calcretes. A metre-scale cyclicity is prevelant in these lagoonal facies and two major types of cycle have been identified. Subtidal cycles show a decrease in circulation, decrease in diversity of organisms and increase in fluctuation of salinity upwards through the cycle. Peritidal cycles shallow upwards from a subtidal base through to an intertidal or supratidal cap. Subtidal cycles seem particularly common within the isolated carbonate complexes, yet both peritidal and subtidal cycles are identified in the shelf lagoon. The distribution of facies and cycles was controlled by a complex interaction of eustasy and differential subsidence. The setting (i.e., whether it was the shelf lagoon, or isolated carbonate complex) also influenced this distribution. Fischer plots were used successfully to correlate successions across the carbonate platform, and to identify areas of condensed or expanded sedimentation. Cycles were calculated to have a duration of approximately 42,000 years for the Upper Givetian. The magnitude of relative sea- level change was in the order of l-3m. The development of the metre-scale cyclicity is best explained by orbital forcing, yet this signature has been overprinted by autocyclic and tectonic noise. Third-order eustatic sea-level fluctuations were delineated by major marine transgressions, and a eustatic sea-level curve was established for the study area.

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Most of the remaining oil reserves are stored in carbonate reservoirs. Improving recovery from these reserves is paramount to uninterrupted energy supply and any future energy transition, should it happen. One of the aspects of recovery improvement is crude oil-brine-carbonate rock interface chemistry. The study of these interactions must be supported by: 1) a correct reactive transport model that describes the advective-dispersive forces in porous media; and 2) convincing experimental evidence consonant with the reactive transport model. As a part of such a larger study, this work addresses some modeling and experimental aspects of dispersive tracer transport through porous media. At both field and laboratory scales, tracer data allows estimation of brine-accessible pore volume and hydrodynamic dispersion. In addition to tracer transport during laboratory-scale coreflood experiments, one typically observes adsorption, dissolution/precipitation, ion-exchange, or all. Without proper tracer data interpretation, these phenomena cannot be distinguished. Therefore, tracer experiments are vital for a meaningful interpretation of any coreflood experiment. The modeling part of the work first discusses choice of boundary conditions that capture the peculiarities of laboratory-scale experiments. We find that Robin or third-kind boundary condition in both inlet and outlet is appropriate for description of the experimental results. Next, the modeling part presents a validated numerical approach to simulate dispersive tracer transport through the experimental system with high hydrodynamic dispersion. Tracer coreflood experiments are performed on $1.5''$ by $3''$ Indiana limestone core plugs with high hydrodynamic dispersion due to extreme rock heterogeneity. Chloride ion is used as the tracer in these experiments. Effluent from the cores is collected each 0.1 pore volume, and the concentration history data are recorded for at least 3 pore volumes. Finally, in the last part of this work, we present how the recorded concentration history data were scaled to the dimensionless model output and assess fit quality. The scaling parameters yield porosity and Péclet number that allow estimation of fluid accessible pore volume and hydrodynamic dispersion. The porosity of the core samples estimated from tracer data is close to those measured using helium pycnometer and/or brine imbibition. Very high hydrodynamic dispersion coefficients obtained from the tracer points correlate well with the scarcely published data on Indiana limestone.

Στα πλαίσια αυτής της μεταπτυχιακής διατριβής γίνεται μελέτη των ασβεστολίθων του Νομού Αχαΐας ως αδρανή για κατασκευαστικές και περιβαλλοντικές εφαρμογές. Πραγματοποιήθηκε συλλογή δειγμάτων, μικροσκοπική και μακροσκοπική μελέτη τους, πλήθος εργαστηριακών φυσικομηχανικών και χημικών δοκιμών με σκοπό τον προσδιορισμό της καταλληλότητάς τους ως αδρανή, παρασκευή και πετρογραφική μελέτη σκυροδεμάτων από τα υπό μελέτη αδρανή καθώς και προσομοίωση όξινου υδατικού διαλύματος και εξουδετέρωσή του με τη χρήση των ασβεστολίθων. / -

Research on dolomitic limestones and dolomites from selected localities of the Barrandian, stratigraphically related to the Scyphocrinites Horizon near the Silurian-Devonian boundary, showed the occurrence of two distinct types of dolomite - diagenetic and epigenetic - differing in petrography and genesis. The diagenetic dolomite is quantitatively predominant. It is finely to moderately coarsely grained with crystal size from 20 μm to 450 μm. Crystals of this dolomite form mostly xenotopic and hypidiotopic textures (occasionally even idiotopic). This type of dolomite formed at low temperature and depth by recrystallization of a carbonate mud during early diagenesis, or during subsequent deeper burial. It is also possible that it originated from recrystallization of previously formed syngenetic dolomite. Fine texture of the diagenetic dolomite is a proof of fast dolomitization and of formation of numerous crystallization centers. Very fine-grained variant of dolomite was also detected (forming aphanotopic texture, size of crystals below 0,002 mm). The epigenetic dolomite, also known as baroque or saddle dolomite, is less common than the former one. It forms white, milky-turbid or clear crystals of large dimensions (0.8 - 3.1 mm). The shapes of these crystals are conspicuous, variously twisted,...

The Swedish mining company LKAB is using limestone as additives for the production of its iron ore pellets. The company is considering five new proposals of limestones since the Nordkalk Company is soon no longer able to provide limestone from the Storugns quarry which is the one that is used today. The first purpose in this study was to characterize and compare these five new limestones in respect to their texture and their disintegration during the transport from the quarry to the final destination in Malmberget, considering the Storugns limestone as a reference material. The second aim was to focus on finding any link between texture and disintegration properties of the limestones. Another intention is that the methodology which is used in this study will help the company to consider new proposals of limestones in the future. Six limestones from the Orsa, Storugns, Stucks, Vasalemma, Verdal and Võhmuta quarries were analyzed by an optical microscopy analysis of the textures. Two types of physical tests were also included in the study: a tumbler test and a breakage test. Six different textures were identified by a qualitative thin section analysis which shows similarities between the limestones from different origins but also a high variability of texture within a same quarry. A more quantitative optical microscopy analysis led to the assumption of both the degree of lithification and the amount of initial micro-cracks for each sample. According to the physical test results, the limestones disintegrate as follows, from the less to the more disintegrated: Stucks (7,6%), Storugns (9,4%), Verdal (10,3%), Võhmuta (11,1%), Vasalemma (11,8%) and Orsa (17,6%). There is no evident textural parameter which is controlling directly the disintegration of limestone. However the samples with a rather high lithification and a rather low fracturing disintegrate less than samples with a rather low lithification and a rather high fracturing. It is assumed that the combination of degree of lithification together with the amount of initial micro-cracks is somehow controlling the disintegration of limestone. / Validerat; 20101217 (root)

Hydrothermal veins in the Paleozoic of the Barrrandian testify for fluid migration during diagenesis and/or epigenesis. A more detailed mineralogical and geochemical research of these veins has started since the end of the 20th century. The subject of a research included in this thesis is determination of conditions of formation of syntectonic calcite and quartz-calcite veins in the lokality called Žák's quarry in Velká Chuchle. This thesis is based on field determination of succession of hydrothermal veins and laboratory study of fluid inclusions in minerals as a basic tool for determination of temperatures during formation of veins. In total, there were distinguished four types/generations of calcite and quartz-calcite veins in Žák's quarry (from oldest to youngest): 1) veins of ,,beef calcite", 2) veins with flat crystals of smoky quartz located in joints perpendicular to bedding, 3) shear veins with calcite located in the big fold, 4) a big calcite vein with tectonic striae spatially bound to significant local fault. Veins have thickness aproximatelly from 1 mm to about 15 cm. By the way, veins of ,,beef calcite" are characteristic by orientation of prolonged grains of calcite in the direction orthogonal towards to the plane of vein. The microscopic study of fluid inclusions revealed presence of...

<p> The Middle Devonian Dundee Limestones of Southwestern Ontario accumulated in the Michigan and Appalachian Basins, with deposition in part being controlled by the proximity to the Findlay and Algonquin arches. Six lithofacies were recognized in the Dundee Formation during detailed core and outcrop studies . Stratigraphic relations indicate that, prior to deposition of Dundee carbonates, a major regression exposed underlying Detroit River sediments adjacent to the arches. Subsequent transgression deposited reworked sands and shallow shelf, bioclastic limestones in most areas of the adjoining basins while in westernmost regions of the Appalachian Basin Columbus Formation sediments were accumulating adjacent to the Findlay Arch. </p> <p> Transgression became interrupted during middle Dundee time and a thick unit of lagoonal muds was deposited in the Appalachian Basin. A regionally well-developed firmground capping these mudstones indicates that a significant episode of non-deposition ensued. The equivalents of these muds in the Michigan Basin are pulses of coarse, reworked grainstones and rudstones indicating that substrates there were shallower and above wave base. Evidence of subsequent renewed transgression is preserved as middle to outer shelf moderately fossiliferous mudstones and wackestones overlying shallow shelf facies. </p> <p> Many friends, too many to mention here, made my stay at McMaster an enjoyable one. Mac wouldn't have been the same without the numerous challenges and imaginative adventures in which these people were always willing to participate. Francois Brissette, Bruce Willmer, Randy Meecham, Stu Miller, Steve Beneteau and other members of the Rockbusters Football and Aureoles Baseball teams provided continuous entertainment both on and off of the sports field. Their dedication and light-hearted approach allowed me to maintain a respectable degree of sanity throughout my studies. </p> <p> Finally, I would like to thank my family for their continual assistance, encouragement and support provided during the pursuit of my academic endeavours. </p> / Thesis / Master of Science (MSc)

<p> Limestones exposed in the intertidal zone display numerous pits and basins which form where bodies of water are isolated during tidal retreat. These harbour both macro- and microscopic organisms whose metabolites enhance aggressivity and cause solution; grazing and boring activities further aid rock removal.</p> <p> In this area the basins are similar in shape throughout the littoral zone but they vary in size, the maximum relief being at mid tide level. Unlike the exposed west coast of Ireland, zonation is not well defined: the clearly identifiable morphologies associated with the biological zones in Ireland are not displayed here. Instead it resembles the karren of the more sheltered Bristol channel area but with less mechanical erosion. In both of these areas variations in lithology affect the details of the geomorphology, some beds being significantly more fractured and less pitted than others.</p> / Thesis / Candidate in Philosophy

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