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[Truncated abstract] The Tintina Gold Province (TGP) comprises numerous (<15) gold belts and districts throughout interior Alaska and Yukon that are associated with Cretaceous plutonic rocks. With a gold endowment of ∼70Moz, most districts are defined by their placer gold contributions, which comprise greater than 30 Moz, but four districts have experience significant increases in gold exploration with notable discoveries at Fort Knox (5.4 Moz), Donlin Creek (12.3 Moz), Pogo (5.8 Moz), True North (0.79 Moz), and Brewery Creek (0.85 Moz). All significant TGP gold deposits are spatially and temporally related to reduced (ilmenite-series) and radiogenic Cretaceous intrusive rocks that intrude (meta-) sedimentary strata. The similar characteristics that these deposits share are the foundation for the development of a reduced intrusion-related gold deposit model. Associated gold deposits have a wide variety of geological and geochemical features and are categorized as intrusion-centered (includes intrusion-hosted, skarns and replacements), shear-related, and epizonal. The TGP is characterized by vast, remote under-explored areas, unglaciated regions with variable oxidation depths and discontinuous permafrost, which, in combination with a still-evolving geological model, create significant exploration challenges. Twenty-five Early and mid-Cretaceous (145-90 Ma) plutonic suites and belts are defined across Alaska and Yukon on the basis of lithological, geochemical, isotopic, and geochronometric similarities. These features, when combined with aeromagnetic characteristics, magnetic susceptibility measurements, and whole-rock ferric:ferrous ratios define the distribution of magnetite- and ilmenite-series plutonic belts. Magnetite-series plutonic belts are dominantly associated with the older parts of the plutonic episode and comprise subduction-generated metaluminous plutons that are distributed preferentially in the more seaward localities dominated by primitive tectonic elements. Ilmenite-series plutonic belts comprise slightly-younger, slightly-peraluminous plutons in more landward localities in pericratonic to continental margin settings. They were likely initiated in response to crustal thickening following terrane collision. The youngest plutonic belt forms a small, but significant, magnetite-series belt in the farthest inboard position, associated with alkalic plutons that were emplaced during weak extension. Intrusion-related metallogenic provinces with distinctive metal associations are distributed, largely in accord with classical redox-sensitive granite-series. Copper, Au and Fe mineralisation are associated with magnetite-series plutons and tungsten mineralisation associated with ilmenite-series plutons. However, there are some notable deviations from expected associations, as intrusion-related Ag-Pb-Zn deposits are few, and significant tin mineralisation is rare. Most significantly, many gold deposits and occurrences are associated with ilmenite-series plutons which form the basis for the reduced intrusion-related gold deposit model

The Aptian-Santonian(?) Bisbee Group in the Whetstone Mountains comprises 2375 m of clastic sedimentary rocks and limestones. The basal Glance Conglomerate unconformably overlies the Pennsylvanian-Permian Naco Group. It consists of limestone conglomerates which were deposited in proximal alluvial fan environments. The superadjacent Willow Canyon Formation contains finer grained rocks which were deposited in the distal portions of alluvial fans. The lacustrine limestones in the Apache Canyon Formation interfinger with and overlie these alluvial fan facies. The overlying Shellenberger Canyon Formation is composed mostly of terrigenous rocks derived from westerly terranes. This formation contains thick sequences of fluvio-deltaic facies as well as a thin interval of estuarine deposits which mark a northwestern extension of the marine transgression in the Bisbee -Chihuahua Embayment. The youngest formation (Upper Cretaceous?) in the Bisbee Group, the Turney Ranch Formation, consists of interbedded sandstones and marls which were deposited by fluvial and marine(?) processes.

Mgr. Petr Schnabl - Dissertation Paleomagnetism and magnetomineralogy of rocks from the Bohemian Massif and Tethyan Realm Abstract The thesis deals with paleomagnetic and rock magnetic properties of Silurian/Devonian and Jurassic/Cretaceous limestones, Paleogene/Neogene basaltic rocks and altered Silurian basalts. The main goal is to determine the history of the Earths' magnetic field from the Silurian to the present. Two lithostratigraphic formations are defined in the Jičín volcanic field on the basis of volcanology, paleomagnetism and radiometric dating. The Trosky Formation (24.6?/18.3 - 15.7 Ma) is composed of several Strombolian-type volcanoes, while the Kozákov Formation (5.2 - 4.6 Ma) is represented by effusive products with a crater vent of a single giant volcano. One Pliocene (4.3-3.3 Ma) and two Pleistocene phases (2.6 -2.1 Ma and 1.8 - 1.1 Ma) of volcanic activity Magnetostratigraphy is a very important tool for the definition of the J/K boundary. The boundary between the Crassicolaria and Calpionella zones is present within geopolarity zone M19n. The boundary between the ammonite zones Jacobi and Durangites also lies close to this point. Paleomagnetic directions of Silurian and Devonian rocks in the Bohemian Massif are very difficult to interpret and have been studied as a challenging problem...

Aus Patagonien lagen bisher wenige Daten zu paläoökologischen Veränderungen und zur Paläobiodiversität an der Kreide-Paläogen (K/Pg)-Grenze vor. Um diese Lücke zu schließen, wurden in den argentinischen Provinzen Neuquén und Chubut zahlreiche Profile im Bereich der K/Pg-Grenze detailliert beprobt. Während einer Planktonkrise, wie sie für die K/Pg-Grenze angenommen wird, werden für benthische Mollusken folgende Entwicklungen erwartet: 1. eine Abnahme der Individuenzahlen der Benthosorganismen, 2. eine Abnahme der vom Plankton als Nahrungsquelle direkt abhängigen Organismen, 3. eine Abnahme der Benthonten mit planktotrophen Larvalstadien, 4. eine Abnahme der mittleren Körpergröße der Individuen benthischer Faunengemeinschaften und 5. eine Abnahme der Organismen mit hoher Stoffwechselrate bzw. aktiver, mobiler Lebensweise. Tatsächlich waren die hungerresistenten Gruppen der Nuculoida (flach-infaunale Depositfresser) und der Lucinidae (Chemosymbionten) im Danium signifikant häufiger als im Maastrichtium, während der Faunenanteil der Suspensionsfresser im Danium im Vergleich zum Maastrichtium signifikant niedriger ist. In den Faunengemeinschaften des Daniums von Bajo de Añelo konnten Abnahmen der Individuenzahlen, der mittleren Mobilität und der mittleren Größe festgestellt werden. Die beobachteten paläoökologischen Veränderungen zeigen somit eine Selektivität, die sich auch in der Paläobiodiversitätsdynamik widerspiegelt. Auch hier sind Suspensionsfresser, die direkt vom Planktonangebot abhängig sind, stärker betroffen als Chemosymbionten und flach-infaunale Depositfresser. Die Aussterberaten für Bivalven sind mit 28% moderat. Insgesamt sind die festgestellten Selektivitätsmuster konsistent mit den zu erwartenden Folgen einer Planktonkrise. Trotz einiger regionaler Unterschiede handelte es sich um ein globales Ereignis an der K/Pg-Grenze, das Nord- und Südhalbkugel gleichermaßen betroffen hat. / From Patagonia only a few data on palaeoecological changes and on palaeobiodiversity at the Cretaceous/Paleogene (K/Pg)-boundary are available so far. Therefore detailed samples in different K/Pg-sections in the Argentinian provinces of Neuquén and Chubut were taken to increase the data set for this region. The following trends are expected from a crisis of primary productivity in the aftermath of the K/Pg-boundary: 1. a reduction in the number of individuals of benthic organisms, 2. a decrease in the relative abundance of organisms which rely directly on photosynthesis, 3. a lower proportion of individuals with planktotrophic larval stages, 4. a reduction in the average body size of individuals within palaeocommunities and 5. an increased abundance of organisms with low metabolic rates or inactive lifestyles. In fact the proportion of the starvation-resistant groups of the Nuculoida (shallow-infaunal deposit feeders) and Lucinidae (chemosymbionts) were significantly higher in the Danian compared to the Maastrichtian. In contrast to this, the proportion of suspension feeders in the palaeocommunities was significantly lower in the Danian in comparison with the Maastrichtian. In the Danian benthic assemblages of the Bajo de Añelo area, a decrease in number of individuals, mean mobility and mean size was recognised after the K/Pg-boundary. Thus the palaeoecological changes display a selectivity, which is also reflected in the palaeobiodiversity. Suspension feeders, which depend directly on plankton particles from the water column, show higher extinction rates than chemosymbionts and shallow-infaunal deposit feeders. The extinction rates of Patagonian bivalves are moderate (28%). Overall, the recognized selectivity patterns are consistent with the expected aftermath of a crisis in primary productivity. Despite some local differences, the results argue for a global event at the K/Pg-boundary during which the northern and southern hemispheres were similarly affected.

The Late Cretaceous–early Paleogene is the most recent period of Earth history with a dynamic carbon cycle that experienced sustained global greenhouse warmth and can offer a valuable insight into our anthropogenically-warmer future world. Yet, knowledge of ambient climate conditions and evolution of the carbon cycle at this time, along with their relation to forcing mechanisms, are still poorly constrained. In this thesis, I examine marine sediments recovered from the South Atlantic Walvis Ridge (ODP Site 1262) and Indian Ocean Ninetyeast Ridge (IODP Site U1443 and ODP Site 758), to shed new light on the evolution of the climate and carbon cycle from the Late Maastrichtian through to the Early Eocene (~67.10–52.35 Ma). The overarching aims of this thesis are: 1) to identify the long-term trends and principle forcing mechanisms driving the climate and carbon cycle during this time period, through construction of 14.75 million-year-long, orbital-resolution (~1.5–4 kyr), stratigraphically complete, benthic stable carbon (δ13Cbenthic) and oxygen (δ18Obenthic) isotope records; 2) to investigate in more detail the climatic and carbon-cycle perturbations of the Early–Middle Paleocene (e.g., the Dan-C2 event, Latest Danian Event and the Danian/Selandian Transition Event) and place these in their proper (orbital) temporal context; 3) to investigate the Late Maastrichtian warming event and its relationship to the eruption of the Deccan Traps Large Igneous Province, as well as its role (if any) in the subsequent Cretaceous/Paleogene (K/Pg) mass extinction; 4) to provide the first orbital-resolution estimates of temperature and carbonate chemistry variability from the low latitude Indian Ocean spanning the Late Paleocene–Early Eocene, through analysis of trace element and stable isotope data from multiple foraminiferal species. Taken together, the results presented in this thesis provide a critical new insight into the dynamic evolution of the climate and carbon cycle during the greenhouse world of the early Paleogene, and shed light on the potential forcing mechanisms driving the climate and carbon cycle during this time.

The Frontier Formation in the Green River Basin of southwestern Wyoming consists of Late Cretaceous (Cenomanian-Turonian) marine and non-marine sandstones, siltstones, mudstones and coals deposited on the western margin of the Cretaceous Interior Seaway. Tight gas reservoirs exist in subsurface fluviodeltaic sandstones in the upper Frontier Formation (Dry Hollow Member) on the north-south trending Moxa Arch within the basin. These strata crop out in hogback ridges of the Utah-Idaho-Wyoming Thrust Belt approximately 40 km west of the crest of the Moxa Arch. Detailed, quantitative outcrop descriptions were constructed using emerging photogrammetric techniques along with field observations and measured sections at five key outcrop localities along the thrust belt. Understanding the architectural style of this low net-to-gross fluvial system allows for improved reservoir prediction in this and other comparable basins. The architectural style of the Dry Hollow Member fluvial deposits varies vertically as the result of a relative shoreline transgression during Dry Hollow deposition. Amalgamated conglomerates and associated fine to coarse sandstones near the base of the section and much thinner, isolated sandstones near the top of the Dry Hollow occur in laterally extensive units that can be identified over tens of kilometers. These units also provide means to relate outcrop and subsurface stratigraphic architecture. Combined with available subsurface data, fully-realized 3D static reservoir models for use as analogs in subsurface reservoir characterization may be constructed. Grain size, reservoir thickness and connectivity of fluvial sandstones is generally greatest near the base of this member and decreases upward overall. Despite relative isolation of some channel bodies, geocellular facies modeling indicates good lateral and vertical connectivity of most channel sandstones. The Kemmerer Coal Zone, with little sandstone, divides lower and upper well-connected sandy units.

ABSTRACT In the first part of this study, a determinist mathematical approach is used to describe any kind of pollutant migration in groundwater. This theoretical background is focused on the miscible displacement and the particularities of the multiporous media are discussed. Subsequently, an objective numerical tool is developed to solve the convection-dispersion equations including immobile water effect, degradation, and adsoption. Among all the available techniques, two finite element methods in fixed meshing grids have been programmed: -the F.U.P.G. method (Full Upwind Petrov Galerkin), using a space-time upwinded weighting function with optimized coefficients, -the H.E.L.M. method (Hybrid Eulerian Lagrangian Method), using the eulerian lagrangian approach with reverse node tracking. Those two schemes are tested on a large number of reference problems. The model have been applied to study the behaviour of solutes (nitrates mainly) in the cretaceous chalk of the Hesbaye area (Belgium). Experimentations have been performed on domains of increasing size (laboratory tests, in situ tracer tests). For each interpretation, the particularities of the context have been taken into account, and miscible transport coefficients have been objectively determined. Hence, the medium is well characterized and the scale effect is quantified. This leads to previsional applications. RESUME Ce travail débute par le développement dun formalisme mathématique déterministe pour décrire, en toute généralité, la propagation de polluants dans les eaux souterraines. Cette étude théorique permet de situer le problème posé (pollution miscible diluée) dans un cadre plus large, et de souligner les particularités dun milieu à porosité multiple. Dans un second temps, un outil numérique objectif est mis au point pour résoudre les équations de convection-dispersion avec effet deau immobile, dégradation, et adsorption. Parmi le grand nombre des procédés existants, deux méthodes par éléments finis en maillage fixe ont été programmées : -la méthode F.U.P.G. (Full Upwind Petrov Galerkin) basée sur un décentrage des fonctions de pondération, optimum dans le temps et lespace, -la méthode H.E.L.M. (Hybrid Eulerian Lagrangian Method) utilisant un processus eulerien lagrangian avec traçage inverse des positions nodales. Les deux schémas sont testés sur de nombreux problèmes de référence. Ensuite, ce modèle est appliqué à des situations pratiques pour étudier le comportement de solutés (nitrates notamment) dans laquifère crayeux du Crétacé de Hesbaye (Belgique). Des domaines de taille croissante sont étudiés (essais de laboratoire, traçage in situ). A chaque étape, les coefficients de transport miscible sont déterminés de façon objective, en tenant compte de la spécificité des tests. Ainsi, leffet déchelle peut être quantifié et il est possible denvisager des scénarios prévisionnels.