Understanding the stratigraphic architecture of geologically complex reservoirs, such as the heavy oil deposits of Western Canada, is essential to achieve an efficient hydrocarbon recovery. Borehole and 3-D seismic data were integrated to define the stratigraphic architecture and generate 3-dimensional geological models of the Mannville Group in Saskatchewan. The Mannville is a stratigraphically complex unit formed of fluvial to marine deposits. Two areas in west-central and southern Saskatchewan were examined in this study. In west-central Saskatchewan, the area corresponds to a stratigraphically controlled heavy oil reservoir with production from the undifferentiated Dina-Cummings Members of the Lower Cretaceous Mannville Group. The southern area, although non-prospective for hydrocarbons, shares many similarities with time-equivalent strata in areas of heavy oil production. Seismic sequence stratigraphic principles together with log signatures permitted the subdivision of the Mannville into different packages. An initial geological model was generated integrating seismic and well-log data Multiattribute analysis and neural networks were used to generate a pseudo-lithology or gamma-ray volume. The incorporation of borehole core data to the model and the subsequent integration with the lithological prediction were crucial to capture the distribution of reservoir and non-reservoir deposits in the study area. The ability to visualize the 3-D seismic data in a variety of ways, including arbitrary lines and stratal or horizon slicing techniques helped the definition of stratigraphic features such as channels and scroll bars that affect fluid flow in hydrocarbon producing areas. Small-scale heterogeneities in the reservoir were not resolved due to the resolution of the seismic data. Although not undertaken in this study, the resulting stratigraphic framework could be used to help construct a static reservoir model. Because of the small size of the 3-D seismic surveys, horizontal slices through the data volume generally imaged only small portions of the paleogeomorphologic features thought to be present in this area. As such, it was only through the integration of datasets that the geological models were established.

The use of Dynamic Global Vegetation Models (DGVMs) in paleo-vegetation studies is a practical new approach in paleo-ecology as it allows for process-based investigations within a flexible framework. The goal of this study is to evaluate the applicability of Lund Potsdam Jena (LPJ) – DGVM in a paleo-study of Cretaceous angiosperm spread, while testing several pre-existing theories regarding the spread through model experimentation. I assessed the independent and interactive role of climate variables (temperature, precipitation, atmospheric CO2 concentration, and seasonality), latitudinal light regime, soil structure, and plant characteristics (tree versus grass, and deciduousness) in influencing angiosperm expansion by simulating the response of Cretaceous land cover to changes in each factor. I found that temperature and light were the most influential variables in determining angiosperm success, while plant structure and deciduousness may carry implications for early angiosperm establishment and community competition dynamics. LPJ showed great potential for refinement and effective future use in paleo-applications.

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No description available.

No description available.

The use of Dynamic Global Vegetation Models (DGVMs) in paleo-vegetation studies is a practical new approach in paleo-ecology as it allows for process-based investigations within a flexible framework. The goal of this study is to evaluate the applicability of Lund Potsdam Jena (LPJ) – DGVM in a paleo-study of Cretaceous angiosperm spread, while testing several pre-existing theories regarding the spread through model experimentation. I assessed the independent and interactive role of climate variables (temperature, precipitation, atmospheric CO2 concentration, and seasonality), latitudinal light regime, soil structure, and plant characteristics (tree versus grass, and deciduousness) in influencing angiosperm expansion by simulating the response of Cretaceous land cover to changes in each factor. I found that temperature and light were the most influential variables in determining angiosperm success, while plant structure and deciduousness may carry implications for early angiosperm establishment and community competition dynamics. LPJ showed great potential for refinement and effective future use in paleo-applications.

Abstract Dissimilatory microbial sulfate reduction (MSR) The specific objectives of the study were to provide the first measurements of sulfur isotope fractionation associated with acidophilic sulfate reducing-microorganisms, and to examine whether pH influences sulfur fractionation during MSR. The fractionation associated with the strains investigated was comparable to that of neutrophilic strains with similar metabolisms (4-12‰), but varied with pH. Two fractionation regimes were identified: one regime is consistent with fractionation during exponential growth, while the other – not identified previously - is not linked to active sulfate reduction and may result from internal sulfate accumulation. This would represent the first measurement of sulfur fractionation during sulfate uptake, the first step of MSR. Geological processes at the Cretaceous-Paleogene (KPg) boundary The KPg boundary is associated with one of the largest biological extinctions in the history of our planet. Two major geologic events - the Chicxulub bolide impact with evaporite terrane and the eruption of the Deccan continental flood basalts - coincide with the KPg boundary and have been identified as possible triggers for the extinctions, but their relative timing remains unresolved. The objectives of this study were to identify the contribution of these processes to the sulfur burden in the sedimentary environment of two freshwater KPg sections, and to determine their relative timing. The results demonstrate that the peak of Deccan volcanism post-dates the Chicxulub impact and the associated abrupt KPg mass extinction, thus precluding a direct volcanic causal mechanism, but shedding light on the underlying causes for the delayed recovery of ecosystems in the early Paleogene.

Abstract: This palynostratigraphic study of Mesozoic successions in hydrocarbon-prospective Tanzanian coastal basins utilizes cores, ditch cuttings, and outcrop samples. These contain rich and diverse dinoflagellate suites ranging in age from Middle Jurassic (Bajocian) to earliest late Cretaceous (Cenomanian). Spores and pollen grains are also recorded, but these are, with some exceptions, subordinate to the dinoflagellate components.In the systematic section, one new dinoflagellate cyst genus, Kipatimudinium, is formally described and nine new species are established: Amphorulla ruvuense, Dichadogonyaulax mandawaense, Egmontodinium annaiae, Hystrichodinium playfordii, Kipatimudinium foliatum (type species), Limbodinium patulum, Pseudoceratium redactum, Sentusidinium tanzaniensis, and Yalkalpodinium africanum. Six, informal, stratigraphically successive dinoflagellate assemblages are distinguished:Assemblage I (Bajocian-Bathonian); Assemblage II (Callovian); Assemblage III (Oxfordian); Assemblage IV (Kimmeridgian-Tithonian); Assemblage V (Berriasian-Barremian); and Assemblage VI (Aptian-Cenomanian).Coastal Tanzania appears referable to the Austral dinoflagellate realm due to the presence of, inter alia, Broomea ramosa, Komewuia glabra, Wanaea clathrata, and Wanaea digitata. Some minor biostratigraphic anomalies are noted, including the introduction of Glossodinium dimorphum; this is datable as early Oxfordian in Tanzania whereas in Australasia the species appears earlier (in the Callovian). A few noteworthy quantitative phenomena are evident; for instance, the abundance of Lithodinia jurassica in the vicinity of the Callovian-Oxfordian boundary and the marked increase of Wanaea spp. in the Oxfordian, specifically in the Ruvu Basin of the northern coastal belt. These events are of chronostratigraphic significance and could be applicable to regional correlation. Middle-Late Jurassic assemblages show a conspicuous degree of cosmopolitanism, and include some species previously considered to be restricted to certain regions in the low and high latitudes.The Early Cretaceous (Berriasian-Barremian) assemblages show close affinity to the Tethyan Realm. The latest Early Cretaceous (Albian) to earliest Late Cretaceous (Cenomanian) strata are allied to the Albian-Cenomanian Elaterates province. The presence of elater-bearing pollen in offshore and onshore sections of Tanzania indicates that the elaterates had a wider geographic distribution than previously reported: i.e., extending beyond the northern part of the African and South American continents.The lower part of the Kipatimu Formation, which contains Assemblage IV, yielded Komewuia glabra, Broomea ramosa, and Rigaudella aemula and their presence precludes the Early Cretaceous age previously ascribed to this part of the formation. Likewise the Makonde and Mkindani Beds have yielded typically Early Cretaceous pollen grains including Classopollis braziliensis, Retitricolpites vulgaris, and Elaterocolpites castelainii.The Jurassic/Cretaceous boundary is coincident with the upper limit of Assemblage IV based on the last appearances of, in particular, Komewuia glabra and Rigaudella aemula. Within the Kipatimu Formation (as represented in wells SS-5 and SS-7), the systemic boundary appears conformable. But elsewhere in the coastal belt, the boundary is clearly unconformable.On the basis of palynostratigraphic data, significant biostratigraphic events, such as introductions and exits of certain dinoflagellate species often match sequence boundaries.From palynofacies analyses and palynostratigraphic data the Kipatimu Formation is dominated by phytoclasts indicating high terrestrial inputs during its deposition. Abundance of black wood (of high buoyancy) in the majority of samples implies high energy settings and abundance of brown wood (less buoyant) is an indication of a sudden terrestrial input into the marine system. The organic composition of sedimentary rocks is an important means of which the depositional history of the enclosing sediments can be understood. Different environmental settings clearly influence the character of palynofacies. For example, abundant chorate cysts (e.g., Systematophora spp.) in samples from the upper sections of SS-5 suggest open marine settings. Therefore, palynofacies analyses can be viewed as providing useful pointers to interpreting the environmental circumstances in which the rocks, in this case the Kipatimu Formation, were deposited.

Os teleósteos são o grupo mais diversificado entre os vertebrados e seu registro mais antigo data do Jurássico. Sua atual classificação inclui quatro clados, dentre os quais Euteleostei é o mais avançado e variado. Apesar de todos os trabalhos a respeito do grupo, ele ainda não possui diagnose, definição e composição precisas. A discordância entre autores é ilustrada pelas nove diferentes propostas filogenéticas elaboradas nos últimos 30 anos. Muitos fósseis do Cretáceo são classificados como euteleósteos basais por falta de conhecimento morfológico, enquanto outros fósseis possuem classificação sistemática controversa ou compartilham aspectos estruturais com euteleósteos basais. Nesse contexto, os objetivos da presente dissertação são avaliar o monofiletismo de euteleósteos basais e recuperar relações filogenéticas de táxons do Nordeste do Brasil, África, Europa, Ásia e América do Norte atribuídos aos euteleósteos basais. Sete táxons brasileiros (i.e., Beurlenichthys ouricuriensis, Britoichthys marizalensis, Clupavus brasiliensis, Santanasalmo elegans, Santanichthys diasii, Scombroclupeoides scutata e novo euteleósteo da Bacia de Pelotas) e 14 táxons de localidades estrangeiras (i.e., Avitosmerus canadensis, Barcarenichthys joneti, Chanoides macropoma, Clupavus maroccanus, Gaudryella gaudryi, Humbertia operta, Kermichthys daguini, Leptolepides spratiiformis, Lusitanichthys characiformis, Nybelinoides brevis, Orthogonikleithrus leichi, Pattersonella formosa, Wenzichthys congolensis e Tchernovichthys exspectatum) foram analisados através de observação direta, fotografias, desenhos e descrições e submetidos a uma análise de Sistemática Filogenética utilizando o princípio da parcimônia. Três espécies recentes (i.e., Elops saurus, Hoplias malabaricus e Salmo trutta) foram usadas como grupo externo. Sessenta e dois caracteres foram selecionados e, como resultado, seis árvores igualmente parcimoniosas foram obtidas com 325 passos, índice de consistência (CI) de 0,2523 e índice de retenção (RI) de 0,4309. O consenso estrito é representado pela seguinte topologia: ((C. marocanus), (C. brasiliensis, (H. malabaricus + S. diasii))) ((G. gaudryi, (C. macropoma + L. characiformis)), (K. daguini), ((A. canadensis, (novo euteleósteo, (S. elegans + W. congolensis), (B. ouricuriensis + B. marizalensis)), (L. spratiiformis, (S. scutata, (N. brevis + P. formosa))), (B. joneti), (O. leichi), (H. operta + T. exspectatum), indicando que euteleósteos basais não formam um grupo monofilético e que as atuais sinapomorfias propostas são insuficientes para suportar o grupo. / Teleostei is the most diversified group among vertebrates and its oldest record dates from the Jurassic. It is currently divided into four clades, from which Euteleostei is the most derived and varied one. Despite all the studies on this group, precise diagnosis, definition, and composition are still lacking. The nine different phylogenetic hypotheses proposed in the last 30 years demonstrate the disagreement among authors. Several Cretaceous fossil fishes are assigned to basal euteleosteans due to the lack of morphological data, whereas some others possess a controversial taxonomic classification, and/or share anatomical features with basal euteleosteans. In this context, the goals of the present dissertation are to verify the monophyly of basal euteleosteans and to recover phylogenetic relationships within the taxa from Northeastern Brazil, Africa, Europe, Asia, and North America assigned to basal euteleosteans. Seven Brazilian taxa (i.e., Beurlenichthys ouricuriensis, Britoichthys marizalensis, Clupavus brasiliensis, Santanasalmo elegans, Santanichthys diasii, Scombroclupeoides scutata, and new euteleostean from the Pelotas Basin) and 14 from foregoing localities (i.e., Avitosmerus canadensis, Barcarenichthys joneti, Chanoides macropoma, Clupavus maroccanus, Gaudryella gaudryi, Humbertia operta, Kermichthys daguini, Leptolepides spratiiformis, Lusitanichthys characiformis, Nybelinoides brevis, Orthogonikleithrus leichi, Pattersonella formosa, Wenzichthys congolensis, and Tchernovichthys exspectatum) were analyzed by direct observation, as well as by means of photographs, drawings, and descriptions. After that, these taxa were submitted to a cladistic analysis using the principle of parsimony. Three living species (i.e., Elops saurus, Hoplias malabaricus, and Salmo trutta) were chosen to the outgroup. Sixtytwo characters were selected and, as a result, six equally parsimonious trees were obtained, with a length of 325 steps, consistency index (CI) of 0.2523, and retention index (RI) of 0.4309. The strict consensus tree is represented by the following topology: ((C. marocanus), (C. brasiliensis, (H. malabaricus + S. diasii))) ((G. gaudryi, (C. macropoma + L. characiformis)), (K. daguini), ((A. canadensis, (new euteleostean, (S. elegans + W. congolensis), (B. ouricuriensis + B. marizalensis)), (L. spratiiformis, (S. scutata, (N. brevis + P. formosa))), (B. joneti), (O. leichi), (H. operta + T. exspectatum), indicating that basal euteleosteans are not a monophyletic group and that the current synapomorphies are insufficient to support it.

The Latest Cretaceous period was characterised by global cooling, superimposed on this pattern of climate change were perturbations in global climate. In high palaeolatitude settings in the Southern Hemisphere short term glacial episodes may have occurred through the latest Cretaceous. The extensive sedimentary succession within the James Ross Basin, Antarctica, provided an opportunity to test the possibility of late Cretaceous glaciation in particular through the succession exposed on Seymour Island. A high resolution oxygen and carbon stable isotope record through the Late Maastrichtian – Early Danian was generated by analysing diagenetically unaltered aragonite nacre shell material from a molluscan fauna collected from the López de Bertodano Fm., part of the Marambio Group present on Seymour Island, Antarctica. The Marambio Group forms an extensive 1100 m thick Late Maastrichtian section that crops out over ~70 km2 of the southernmost part of the island. Coverage of stable isotope data for the measured stratigraphy was good with 213 screened analyses that included data from within 1 m of the K-Pg boundary located at 1029 m above datum, determined from the first occurrence of the dinoflagellate cyst Senegalinium obscurum. Stable isotope data (‰ VPDB) for primary aragonite from bivalves, cephalopods and gastropods exhibited screened stable isotope data ranges of -0.06 to +2.05‰ for δ18O and -7.54 to +3.7‰ for δ13C. Data showed that at individual stratigraphic levels the range in measured δ18O exhibited significant variability. Benthic specimens provided the majority of the stable isotope data, bivalves exhibited the widest range of δ18O and δ13C values. Data show that individual specimens from the same genus can exhibit significant variability for δ18O and δ13C and that analysis of single samples at discrete stratigraphic levels may provide an erroneous interpretation of climate change. Higher oxygen isotope values were seen mid-section and complement previous records of periods of cooler climate identified from palynology, clumped isotopes and sea level. Palaeotemperatures were calculated for δ18O values for a seawater composition of SMOW = -1.0‰, representing an ice free ocean, 6 to 14°C for bivalves, 9 to 12°C for gastropods and 9 to 15°C for cephalopods. Temperatures indicated relatively stable benthic temperatures (~10°C) with a cooling phase that commenced at ~450 m (~69.5 Ma) with the coolest temperatures developed at ~630 m (~69 Ma). Cooling trends showed a good correlation with the position of seawater lowstands. Thereafter temperatures recovered towards the K-Pg boundary before a cooling trend developed that closely correlated with the PaDa1 lowstand. Acceptance of Deccan Traps volcanism as a causal mechanism for the limited degree of observed warming close to the K-Pg event was limited by a lack of suitable specimens.