O Triássico é um período de grande importância na história da vida na terra, durante o qual grandes eventos evolutivos são registrados dentre os vertebrados. Para melhor compreender a transição entre a fauna dominada por terápsidos no início do período para uma fauna dominada por dinossauros no final, tem se intensificado os estudos correlacionando sedimentos triássicos de forma global. Essencial para subsidiar tais correlações, é uma bioestratigrafia regional detalhada. No Brasil, tetrápodes triássicos são conhecidos apenas nos depósitos do Grupo Rosário do Sul, no Rio Grande do Sul. Com base nesses fósseis, muitas propostas bioestratigráficas foram elaboradas, ainda que de forma preliminar. Visto que a busca por novos sítios fossilíferos e descoberta de novos fósseis têm gerado grande acúmulo de dados sobre o Triássico brasileiro, mas poucos trabalhos de catalogação dessa informação foram desenvolvidos, acreditamos que parte das dificuldades no estabelecimento de um zoneamento bioestratigráfico de maior detalhe, neste caso, é decorrente de uma disponibilização ainda inadequada dos dados referentes ao conteúdo fossilífero de cada uma das localidades prospectadas na região. Visando sanar tal obstáculo, o presente trabalho teve como objetivo inicial a elaboração de um banco de dados acerca de tais tetrápodes triássicos, com o resgate das informações já publicadas sobre o tema, além de levantamento in loco de espécimes catalogados em determinadas coleções do Estado. Este banco de dados foi utilizado para testar as propostas bioestratigráficas vigentes através do estudo das similaridades faunísticas, com detalhamento em nível de localidades, através da aplicação de estatística multivariada (análises de cluster) em diferentes graus de abrangência taxonômica. Foram utilizados os índices de similaridade de Jaccard (qualitativo) e de Morisita-Horn (quantitativo) para a construção da matriz de distância, e o método de agrupamento de Ward para geração dos dendogramas. Os agrupamentos resultantes de análises qualitativas foram os que mais coincidiram com as propostas bioestratigráficas prévias. As demais análises, quantitativas, não resultaram em agrupamentos verossímeis, o que não se deve a problemas na utilização do método, mas da utilização de táxons que não são adequados a estudos bioestratigráficos. / The Triassic is a period of great importance in the history of life on Earth, where important evolutionary events occurred among the vertebrate lineages. To better understand the transition between a terapsid dominated fauna of the beginning of the period to one dominated by dinosaurs at its end, studies of the correlation of Triassic sediments at a global scale have been intensifying in recent years. Essential to subsidize such correlations is a detailed regional biostratigraphy. In Brazil, Triassic tetrapods are known only in the deposits of the Rosario do Sul Group, Rio Grande do Sul State. Based on these fossils, many biostratigraphical proposals have been elaborated, but are still considered as preliminary ones. As the search for new fossil sites and new discoveries generate an accumulation of data about the Brazilian Triassic, few works on the allocation of this information have been developed, however, and we believe that part of the difficulty in establishing a more detailed biostratigraphical zonings for this is due to the inadequate availability of data on the fossils of every prospected locality in the region. As a means to resolve this obstacle, the main objective of the present work was the construction of a Database of Triassic tetrapods, along with the information already published on the subject, added to an overview in loco of catalogued specimens of certain scientific collections of the State. This Database was used to test the established biostratigraphical proposals by means of a study on faunistic similarities, with detainment at location level, by use of multivariated statistics (cluster analysis) in different levels of taxonomic amplitude. We used Jaccard (qualitative) and Moristia-Hom (quantitative) similarity indexes to construct the distance matrix, and the Wards method of clustering to generate the dendograms. The resulting qualitive analysis produced clusteres that matched more closely with previous biostratigraphical proposals. The other quantative analysis did not result in stable clusters, but this is not due to methodological problems, however, but due to the use of taxa that are not sucitable for biostratigraphical studies.

Estudos relacionados à microestrutura óssea de elementos fósseis surgiram no século XVIII, porém começaram a desenvolver-se mais profundamente somente nas últimas décadas. Hoje, a Paleohistologia é uma das áreas mais promissoras dentro da Paleontologia, pois nos possibilita acessar uma série de características do espécime fóssil que complementam nosso conhecimento sobre o animal. Assim como outros clados, os Dicynodontia vêm sendo estudados por esse viés há muito tempo, e hoje conhecemos os padrões ósseos e de crescimento de um grande número de espécies. A presente dissertação traz a descrição ósteo-histológica de alguns elementos fósseis de Dinodontosaurus turpior, uma espécie de dicinodonte de grande porte do Mesotriássico, encontrada em afloramentos da Formação Santa Maria. Os ossos analisados apresentam majoritariamente uma matriz do tipo fibrolamelar, com alguns subtipos da matriz em dois fragmentos, ausência de linhas de crescimento nos espécimes juvenis e presença destas em fragmentos de espécimes adultos, possibilidade de EFS em um fragmento de adulto, reconstrução secundária surgindo apenas em estágios mais avançados e córtex razoavelmente espesso. Tais características não divergem do padrão já descrito para o grupo como um todo, cujas interpretações para a biologia do animal incluem um metabolismo mais acelerado e uma rápida osteogênese, quando comparada com a de terápsidos mais basais. / Studies related to bone microstructure of fossil elements started about the 18th century, however, they began to significantly grow only in the past few decades. Today, paleohistology is one of the most promising areas inside paleontology, because permits to access several characteristics of the fossil specimen which complement our knowledge about the animal. As in other clades, Dicynodontia has been studied in this subject for long time, and now we know about bone growth and microstructure patterns in a variety of species. The present study shows a osteohistological description of some fossil elements of Dinodontosaurus turpior, a medium-to-large size dicynodont species from Middle Triassic of Rio Grande do Sul, Brazil, founded in outcrops of the Santa Maria Formation. The bones analyzed present a fibrolamelar type of bone tissue as major matrix, with some subtypes appearing in a couple of fragments. Growth lines are absent in all juvenile fragments, but appears in the adult ones. One of the adult fragments seems to have an EFS. Also, it was observed secondary reconstruction in adult sample and a thick cortex in all slides that RBT can be calculated. All these features were already been observed in the Dicynodontia clade, whose biological interpretations include an accelerated metabolism and rapid osteogenesis, when compared with basal therapsids.

O presente trabalho aborda o estudo do argilomineral caulinita. Este, ocorre geralmente como produto de alteração in situ da rocha, sendo definido como caulinita autigênica, ou também pode ocorrer dentro dos processos diagenético (eodiagênese ou telodiagênese). Nos depósitos do Gráben Arroio Moirão ocorre a presença do argilomineral caulinita em todos os perfis levantados, desde a base até o topo. A caulinita encontrada mostra diferente estágios de formação. No primeiro estágio os grãos detríticos são substituídos por uma caulinita com lamelas em estágios iniciais, finas e anédricas. No segundo estágio ocorrem lamelas um pouco mais espessas, com arestas melhor definidas caracterizando uma caulinita subédrica. O terceiro estágio apresenta lamelas bem definidas, mais espessas em relação as iniciais, pseudohexagonais, expondo estrutura em booklets compondo uma caulinita euédrica. Entende-se que devido aos contatos pontuais observados nos grãos detríticos, as rochas do Gráben Arroio Moirão sofreram soterramento não muito profundo configurando uma compactação leve. Provavelmente estes sedimentos se enquadram dentro do processo de eodiagênese, no qual, a temperatura e profundidade caracterizam-se por serem amenos (≤ 70ºC; ≤ 2km). Durante o soerguimento destes pacotes dentro do processo de telodiagênese, as camadas foram expostas a condições intempéricas favoráveis a formação da caulinita. São elas a ação do clima principalmente pela infiltração de água meteórica que utiliza-se do sistema de permeabilidade e porosidade da rocha, bem como falhas e fraturas presentes. Portanto, o argilomineral encontra condições propícias a sua formação, no qual, ocorre substituindo grãos detríticos como feldspatos, micas, fragmentos argilosos, gerando desta forma um processo de caulinização generalizada no Gráben Arroio Moirão. / The survey herein approaches the clay mineral kaolinite study. Either this mineral occurs as a product of a rock alteration in situ, defined as authigenic kaolinite, or it can be developed inside diagenetic processes (eodiagenesis or telodiagenesis). In the Arroio Moirão Graben, the presence of the clay mineral kaolinite is evident in every profile, from the bottom to the top. The kaolinite observed shows different stages of formation. On the first stage, detrital grains are replaced by a kaolinite displaying fine, anedric and incipient lamellae. On the second stage, lamellae are a little bit thicker, presenting better definition to the edges characterizing subedric kaolinite. On the third stage, lamellae are pseudohexagonal, thicker, well ordered and expose booklets structure, forming euhedral kaolinite. Due to the point contacts observed on detrital grains, rocks from Arroio Moirão Graben suffered a not so deep burial, as a result, a slight packing. Probably these sediments are part of eodiagenesis process, where, temperature and depth are mild (≤ 70ºC; ≤ 2km). During the uplift of these rocks under telodiagenesis process, layers were exposed to weathering conditions favorable to kaolinite formation, like rainwater infiltration through permeability and porosity rock system, as well as, faults and joints existent. Therefore, this clay mineral is under favorable conditions to its formation, where kaolinite substitutes detrital grains like feldspars, micas, clay fragments, promoting a widespread kaolinization to Arroio Moirão Graben.

Upper to lower delta plain fluvial sand bodies, sealed by delta plain mudstones, form important hydrocarbon reservoir targets. Modelling complex geobodies in the subsurface is challenging, with a significant degree of uncertainty on dimensions, distribution and connectivity. Studies of modern and ancient paralic systems have produced a myriad of nomenclature and hierarchy schemes for classifying fluvial architectural elements; often lacking clearly-defined terminology. These are largely based on outcrop data where lateral and vertical relationships of bounding scour surfaces can be assessed in detail. Many of these key defining criteria are difficult to recognise or cannot be obtained from typical 3D seismic reflection data at reservoir depths greater than or equal to 2 km subsurface. This research provides a detailed statistical analysis of the Triassic fluvio-deltaic Mungaroo Formation on the North West Shelf of Australia, which is one of the most important gas plays in the world. A multidisciplinary approach addresses the challenge of characterising the reservoir by utilising an integrated dataset of 830 m of conventional core, wireline logs from 21 wells (penetrating up to 1.4 km of the upper Mungaroo Fm) and a 3D seismic volume covering approximately 10,000 km2. Using seismic attribute analysis and frequency decomposition, constrained by well and core data, the planform geobody geometries and dimensions of a variety of architectural elements at different scales of observation are extracted. The results produce a statistically significant geobody database comprising over 27,000 measurements made from more than 6,000 sample points. Three classes of geobodies are identified and interpreted to represent fluvial channel belts and channel belt complexes of varying scales. Fluvial geobody dimensions and geomorphology vary spatially and temporally and the inferred controls on reservoir distribution and architecture are discussed. Results document periods of regression and transgression, interpreted in relation to potential allocyclic and autocyclic controls on the evolution of the depositional system. Statistical analysis of width-to-thickness dimensions and key metrics, such as sinuosity, provided a well-constrained and valuable dataset that augments, and has been compared to, existing published datasets. Uncertainty in interpretation caused by data resolution is addressed; something recognised in many other studies of paralic systems. Given the data distribution, type and resolution, geobodies have possible interpretations as either incised valleys or amalgamated channel belts, with implications for developing predictive models of the system. This study offers the first published, statistically significant dataset for the Mungaroo Formation. It builds upon previous regional work, offering a detailed analysis of this continental scale paralic system and provides insight into the controls and mechanisms that influenced its spatial and temporal evolution. Focusing on improved understanding of geobody distribution and origin, the statistical parameters generated provide a robust dataset that can be used for 3D static reservoir models of analogue systems. Thus, helping to constrain potential geobody dimensions and reduce the uncertainties associated with modelling.

Os depósitos triássicos da Bacia do Paraná no Brasil ocorrem somente no estado do Rio Grande do Sul, mais precisamente, diretamente sobre a porção centro-sul do Escudo Sul-Rio-Grandense entre os paralelos 30º45‟e 31º15‟S e os meridianos 52º45‟e 53º15‟W. Com o objetivo de definir o modelo sedimentar do tipo inundito para os depósitos triássicos contidos no setor nordeste do Gráben Arroio Moirão realiza-se aqui uma abordagem em termos de estratigrafia de sequências. Para tanto, aplicou-se técnicas de mapeamento geológico de rochas sedimentares, levantamento de seis perfis colunares e coleta de amostras de rochas para análises. Com isso, foram definidas dezoito fácies, oito sucessões de fácies, sete superfícies-chave e dois marcadores estratigráficos, o que corroborou com a elaboração do arcabouço estratigráfico para a região de estudo, bem como, com a proposição do modelo deposicional do tipo inundito. As litologias encontradas na região são invariavelmente mal selecionadas, têm grãos angulosos a subangulosos e possuem geometrias em lençóis ou tabulares, características típicas de tal modelo sedimentar. O modelo de inunditos consiste em fluxos subaquosos episódicos progradantes de baixa densidade que com o passar do tempo passam a desenvolver canais efêmeros, que, por sua vez, ocorrem rapidamente por meio de feições rasas e desconfinantes. Há então a etapa transgressiva, quando o nível de base sobe e o fluxo é afogado e, posteriormente, ocorre exposição subaérea. Assim, deposita-se a sequência sedimentar clássica do modelo tipo inundito: a sucessão de fácies granodecrescente ascendente com depósitos tabulares e em lençóis de conglomerados, maciços ou com estratificação cruzada tangencial, intercalados com camadas de arenitos grossos a conglomeráticos, maciços, ou com estratificação cruzada tangencial, por vezes com intraclastos argilosos, seguidos por depósitos tabulares e em lençóis de arenitos de granulometria média a grossa, maciços ou com estratificação cruzada tangencial, cruzada tabular ou plano‐paralela, podendo também conter intraclastos argilosos. Quando há o desconfinamento, depositam‐se arenitos muito finos a finos com laminação plano‐paralela de fluxo superior, maciços ou com estratificação cruzada de baixo ângulo. Após, têm-se os depósitos tabulares de siltitos e lamitos com laminação plano‐paralelo ou maciço, com intercalações de níveis micáceos e feições de exposição subaérea no topo. / In Brazil, the Triassic deposits of the Paraná Basin only occur in the state of Rio Grande do Sul, more precisely, over the south-central portion of the Sul-Rio-Grandense Shield between the parallels 30º45 'and 31º15' S and 52º45 meridians " and 53º15 "W. In order to define the sedimentary model inundito type for Triassic deposits contained in the northwest sector of the Arroio Moirão Graben is held here an approach in terms of sequence stratigraphy. In selected outcrops, by applying geological mapping techniques it was proposed columnar profiles, photographic documentation and the sampling of the units for further analysis. The columnar profiles allowed the recognition of eighteen facies, eight successions of facies, seven key surfaces and two stratigraphic markers, which corroborated with the development of the stratigraphic framework for the study area as well, with the proposition of the a depositional inundite type model, since the lithology found in the region are invariably bad selected, have angular grains subangular and have geometries sheets or tabular, typical features such sediment model with which it is to subaqueous episodic progradational flows low density with the passage of time. They go on to develop ephemeral channels, which, in turn, occur rapidly through shallow desconfinantes features after they have to transgressive step, when the base level rises and the flow is drowned subsequently occurs subaerial exposure. So is deposited classic sedimentary inundite type model: the succession of fining upward facies with tabular deposits and conglomerates sheets, massive or tangential cross bedding, interspersed with layers of coarse to conglomeratic sandstones, massive or cross-stratification tangential, sometimes with clayey intraclasts, followed by tabular deposits and sheets of medium grained sandstones thick, massive or tangential cross bedding, cross-tabular or plane-parallel, and may also contain clay intraclasts. When there is desconfinamento, deposited in very thin sandstones fine with a parallel lamination higher flow, solid or cross-bedding of low angle. Then, there are the tabular deposits siltstones and mudstones with lamination plane-parallel or massive, interlayered with micaceous levels and subaerial exposure features at the top.

The Glacier Creek volcanogenic massive sulfide (VMS) deposit is hosted within Late Triassic, oceanic back-arc or intra-arc, rift-related, bimodal volcanic rocks (Hyd or Tats Group) of the allochthonous Alexander terrane known as the Alexander Triassic Metallogenic Belt (ATMB). The deposit presently consists of four tabular massive sulfide lenses with a resource of 4.75 Mt. at 1.84% Cu, 4.57% Zn, 0.15% Pb, 0.28 g/t Au and 29.07 g/t Ag. A deposit-scale thrust fault offsets stratigraphy along the axial surface of a deposit-scale anticline. The massive sulfide lenses are barite-rich and are divided into 6 main ore-types based on mineral assemblages. There is a large range of sphalerite compositions, with low-Fe sphalerite dominant throughout the lenses and high-Fe sphalerite at the top and bottom of the lenses in pyrrhotite-rich zones. Lenses contain anomalous Sb, Hg and Tl. Gangue minerals include barite, quartz, barian-muscovite, calcite, albite, highly subordinate chlorite and locally hyalophane and celsian. Overlying massive sulfide is a tuffaceous hydrothermal sediment with anomalous REE patterns and local hyalophane. The general footwall to all four lenses is a thick unit of coherent to volcaniclastic feldspar-phyric basalt containing extensive lateral alteration. Four alteration facies are recognized based on mineral assemblages. Mass balance calculations for the footwall indicate general gains of S, Fe, Si and K with coincident loss of Ca, Na and Mg, along with trace element gains of Tl, Sb, Hg, Ba, Zn, Cu, As and loss of Sr with increased alteration intensity. Short wavelength infrared (SWIR) spectroscopy shows a general decrease in Na, K and Al content of muscovite and increase of Fe+Mg and Ba content towards ore. Integrated petrographic, mineral, chemical and sulfur-isotope data suggest a transition during deposit formation, from high-temperature, acidic, reduced hydrothermal fluids mixing with oxidized, SO4-rich seawater, to later cooler, low fO2-fS2 conditions of formation and a lack of SO4 in seawater.

Shallowing-upward meter-scale cycles (parasequences) consisting of megalodont-bearing limestones or clay levels at the bottom and fenestral limestones, breccias, stromatolites or vadose pisoids at the top constitute the basic working units of the Upper Triassic successions in the Central and Western Taurides. These cycles are mainly represented by subtidal through supratidal carbonate facies and known as Lofer cycles in the literature. The presence of breccias, mud cracks, dissolution vugs and vadose pisoids indicates subaerially exposed conditions at the top of the cycles. Shallowing-upward meter-scale cycles are interpreted as 4th and 5th order cycles in this study. Megalodont-bearing limestones of the subtidal zone are characterized by wackestones/packstones with abundant involutinids. However, involutinids are poorly represented in the intertidal-supratidal zone. To determine the relationship between cyclicity and foraminifers, the vertical variation of benthic foraminifer abundance has been analysed in the cycles. This analysis leads us to conclude that the foraminiferal abundance decreases from subtidal through supratidal zone. Furthermore, cluster analysis was performed in order to delineate the relation between the biofacies and foraminiferal associations. Micropaleontological analysis of the uppermost Triassic carbonates reveals the presence of restricted platform foraminiferal associations in the studied successions. Foraminiferal associations discovered in the samples belong to the Upper Norian (Sevatian)-Rhaetian Triasina hantkeni assemblage zone. Detailed examination of peritidal carbonates in the Central and Western Taurides against the studies, which claimed that the Dachstein-type platform carbonates are characterized by the transgressive models, should be explained by regressive models.

The aim of this study is to designate paleontologic, biostratigraphic and sequence stratigraphic characteristics of the Permian-Triassic Boundary beds of the Bolkar Dagi Unit in the Hadim region (Central Taurides). For this purpose a 48,06m thick stratigraphic section, composed of limestone, siltstone and sandstone, was measured and 116 samples were analyzed through the Permian Ta

Opening-mode fracture shapes are typically the result of brittle deformation and proportional growth in fracture height, length, and width. Based on the typical fracture shape, it is assumed that fracture tips are free to propagate in all directions. Some natural rock fractures have been shown to form as a result of slow non-elastic deformation processes. Such fractures may propagate to a finite length or height and accommodate further growth by aperture widening only. To determine the growth conditions of a fracture in the Triassic-Jurassic La Boca Formation of northeastern Mexico and to test fracture growth models, I combined fluid inclusion microthermometry and SEM-based cathodoluminescence cement texture analysis to determine the relative timing of fracture cement precipitation and related fracture opening for five samples collected along its trace. Fracture growth initiated at a minimum age of 70 Ma as two separate fractures with branching fracture tips that coalesced to a single continuous fracture under prograde burial conditions at a minimum age of 54 Ma. At this stage, fracture growth was accommodated by both propagation (i.e. increase in trace length) and by an increase in aperture during maximum burial and early exhumation. Samples collected at the fracture tips recorded temperatures reflecting fracture opening starting with maximum burial at a minimum age of 48 Ma at one tip and of 38 Ma at the other tip. Synkinematic fluid inclusions in crack-seal cement track continued fracture opening close to the fracture tips without a concurrent increase in trace length after 38 Ma until about 21 Ma. I attribute the observed change in fracture growth mechanism to a change in material response. The stage in aperture increase without propagation corresponds to an increase in elastic compliance or in non-elastic flow properties. Non-elastic flow can be attributed to solution-precipitation creep of the host rock. Dissolution of host quartz grains and subsequent quartz precipitation is consistent with the abundance of quartz fracture cement formed during exhumation. Cement textures from fractures in the La Boca Formation mimic those found in subsurface core, which allows application of the results to a variety of geologic environments. / text

Conceptualizations of actual biological patterns as preserved in the fossil record must accommodate the results of biotic and abiotic drivers of faunal dynamics. However, those conceptualizations also may reflect cognitive biases resulting from foundational philosophical stances. Whether fossils are conceptualized as the remains of biological entities or as geological objects will affect both taxonomic identifications and secondary inferences derived from those identifications. In addition, operational research bias centered on relativistic views of ‘importance’ of particular components (i.e., taxonomic or skeletal region) of the assemblage results in preferential documentation of some taxa and marginalization of others. I explored the consequences of those specific cognitive and operational biases through examination of Triassic and Eocene faunal assemblages in western North America. For the Triassic I focused on taxonomic and systematic treatments of Paleorhinus, a group of phytosaurs important for the establishment of biochronologic correlations. Specimen-level reexamination of Paleorhinus supported a restricted usage of Paleorhinus as a clade, dissolved a biochronologic connection between terrestrial and marine deposits, and indicated a prior compression of the early part of the Late Triassic as a result of previous conceptualizations of species. I reexamined the Otis Chalk tetrapod assemblage in light of new specimens and modern phylogenetic frameworks. My examination supported a restricted usage of the Otischalkian for biochronologic correlation of the Late Triassic, and emphasized the importance of apomorphic character-based specimen examinations in conjunction with detailed lithostratigraphy prior to the development of biochronologic schema. For the Eocene I focused on undocumented terrestrial reptiles from the late Uintan fauna of West Texas. Specifically I discovered new taxa and new geographic occurrences of amphisbaenians and caimanine crocodylians. The amphisbaenians represent the southernmost record of the clade in the North American Paleogene, and, when combined with other amphisbaenian records, document that the clade responded to late Paleogene climatic changes in ways different from the inferred mammalian response. The new taxon of caimanine crocodylian represents a new geographic and temporal record of that clade. That new record indicates that the biogeographic range of extant caimans represents a climate-driven restriction from a formerly more expansive range, and suggests that the previous geographic and temporal gap in paleodistribution data is related to sampling biases and is not a solely a biological phenomenon. These data indicate that reliable characterization of vertebrate faunal dynamics requires open acknowledgment and appropriate documentation of cognitive and operational biases that affect interpretations of paleontological data. / text