No description available.

The Late Permian mass extinction occurring at 252.6 ± 0.2 Ma is the most severe Phanerozoic extinction event and was preceded and followed by additional disturbances. Patterns and processes of extinction and recovery of marine vertebrates have been little studied compared to marine invertebrates. This project focuses on Chondrichthyes, which, together with other marine fish, appeared to have been relatively unaffected by the extinction, while most of their supporting ecosystem collapsed. This study explores the authenticity of extinction among chondrichthyans and possible explanations for the observed patterns, because extinction severities on the taxonomic and ecological levels may be decoupled or the quality of the fossil record may be variable. The presented analyses are based on a newly compiled database that supercedes older compilations. It is supplemented by material obtained from numerous localities globally, which includes newly described taxa. Hence, this study attempts to be the most up-to-date and comprehensive analysis of patterns and trends in chondrichthyan diversity and distribution that is currently available. The data demonstrate that, despite some variability in the Permian–Triassic chondrichthyan fossil record, the Lopingian record is shown to be of adequate completeness and, furthermore, range-through genus diversity is not significantly correlated with the number of taxonomic occurrences. Genus diversity declined from the mid-Guadalupian following an increasing extinction rate, which intensified throughout the Lopingian and thus supports a combined overall extinction as a result of the end-Guadalupian and Late Permian events. Furthermore, global distribution of chondrichthyan diversity shifted away from tropical regions and particularly the Boreal Sea gained in diversity, tracking extinction and recovery in marine benthic invertebrates in both time and space. No significant dependence of extinction on taxonomic structure or palaeoecological traits exists, which suggests proportional losses, except during the end-Smithian crisis. Also, a significant size decrease is absent among Permian/Triassic boundary-crossing taxa, suggesting selective loss of large-sized chondrichthyans rather than adaptive size decrease. Ultimately, the Hybodontiformes, Neoselachii, Xenacanthiformes and Holocephali are identified as the survivors, which possessed a varying combination of characteristics such as moderate body-size, adaptation to brackish/freshwater environments, benthic or generalist littoral (clutching) feeding behaviour, and a wide palaeogeographic range.

South Africa remains the 5th largest producer and 4th largest exporter of coal in the world. It is also the largest supplier of coal to the European Union. This fact is significant as the European Union has recently supported the environmental lobby that threatens the combined full scale use of coal in Europe and other first world countries. This promotes the development of clean coal technologies in order to counter the ever increasing number of environmental constraints threatening the export market. One critical development in clean coal technologies is coal beneficiation, which allows the reduction of ash and inert content. Permian coals from South Africa have characteristically high ash and inertinite contents and therefore require further beneficiation. The Witbank coalfield No. 4 seam is no exception. It can be described as being more inert and having a higher mineral content compared to the No. 2 seam in the same coalfield also mined for export purposes. With the increase in environmental legislation and the push towards “clean coal” this raises a concern in terms of the performance and marketability of export coal produced from the No. 4 seam. This seam will in the future be economically significant and is still a great source for export steam coal. Due to the nature and composition of the No. 4 seam, coal beneficiation is essential to reduce the mineral and inert content to be in line with export quality specification levels. Washability characteristics of the No. 4 seam coal indicate that the No. 4 seam is difficult to beneficiate. Until recently the main clean-ability parameters evaluated in South African export coals as per customer specification included mainly heating value, moisture and ash reduction with little to no work being done on trace element concentration reduction. This paper focuses on the partitioning of the trace elements within the seam in relation to the organic and inorganic affinity of the trace elements and possible methods of trace element reduction by removal using coal beneficiation techniques. The techniques investigated include reduction by washing using dense medium beneficiation and flotation. In each evaluation the focus was on trace-element-tomineral and trace-element-to-organic matter relationship and hence setting the basis for liberation analysis to evaluate reducibility. By the evaluation of the coal mineralogy, petrography and trace element relationships, methods of optimum trace element reduction can be established. With the focus on marketing it was shown that carbon loss need not be sacrificed in the reduction of specific trace elements in the No. 4 seam and that the trace element distribution itself allows for beneficiation whilst maintaining acceptable yields. Processes and possible beneficiation techniques for optimum trace element reduction and marketability in the case of the No.4 seam are proposed.

Submitted by Ana Damasceno (ana.damasceno@unipampa.edu.br) on 2016-09-12T19:13:34Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Descrição De Uma Nova Espécie De Anfíbio (Tetrapoda Temnospondyli) Para A Formação Rio Do Rasto (Permiano Da Bacia Do Paraná) E Revisão Do Status Filogenético De Archegosauroidea.pdf: 1777717 bytes, checksum: e8fc95d895ea7e2478fb697730895325 (MD5) / Made available in DSpace on 2016-09-12T19:13:34Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Descrição De Uma Nova Espécie De Anfíbio (Tetrapoda Temnospondyli) Para A Formação Rio Do Rasto (Permiano Da Bacia Do Paraná) E Revisão Do Status Filogenético De Archegosauroidea.pdf: 1777717 bytes, checksum: e8fc95d895ea7e2478fb697730895325 (MD5) Previous issue date: 2015 / Temnospondyli é um grupo bastante diversificado de tetrápodes basais que surgiu no início do carbonífero passando por grandes fases de radiação e extinção, com picos de diversidade no Permiano e no Triássico. Dentro desse grande grupo inclui-se Archegosauroidea, grupo abundante no Leste Europeu, com registro ainda escasso na América do Sul (até o momento, restritos ao Brasil). Esse grupo é dividido em duas famílias, Archegosauridae e Melosauridae. Até então, os registros indiscutíveis de arquegossauróides formalmente descritos para o Gondwana pertenciam à família Archegosauridae, a saber: Prionosuchus plummeri um platiopossauríneo encontrado no estado do Maranhão (Formação Pedra de Fogo) e Bageherpeton longignathus encontrado no Rio Grande do Sul na divisa entre Bagé e Aceguá (Formação Rio do Rasto). Neste trabalho apresenta-se a descrição e análise filogenética do espécie basal do gênero Konzhukovia (anteriormente exclusiva da Rússia) para o Permiano do Gondwana permite fazer novas considerações acerca de sua origem e irradiação, que tanto pode ter se dado na Laurasia com Konzhukovia sendo parte da primeira irradiação de arquegossauróides para o Gondwana ou mesmo Konzhukovia ter se originado no Gondwana e migrado para a Laurásia onde as espécies mais derivadas evoluíram. Além disso, o fato de Konzhukovia fazer parte de uma família basal a Stereospondyli reforça a hipótese de que estes se originaram e diversificaram no Oeste do Gondwana antes do fim do Permiano ao contrário do que sugere a hipótese de que os Stere ospondyli teriam ficado em um refúgio no Leste do Gondwana e teriam se diversificado após a grande extinção no final do Paleozóico. / Temnospondyli is a very diverse group of basal tetrapods that appeared in the Early Carboniferous, going through major phases of radiation and extinction, with peaks of diversity during Permian and Triassic. It includes the Archegosauroidea, an abundant group in Eastern Europe with a few records from South America (so far restricted to Brazil). Achegosauroidea is divided into two families, Archegosauridae e Melosauridae. Until this contribution, unquestionable records of formally described archegosauroids from Gondwana belong to the Archegosauridae, as follows: The platyoposaurinae Prionosuchus plummeri from the Maranhão state (Pedra de Fogo Formation) and Bageherpeton longignathus from the Rio Grande do Sul state (Rio do Rasto Formation). This work presents the description and phylogenetic analysis of the first indubitable tryphosuchine outside Eastern Europe. The new material (UNIPAMPA PV 00137) consists in a partially complete skull collected in 2008 in the Posto Queimado locality (that also belongs to the Rio do Rasto Formation) from São Gabriel municipality, Rio Grande do Sul state. In the phylogenetic analysis presente Russia) in the Permian of Gondwana provide new insights about its radiation and dispersion, which may have happend on Laurasia with Konzhukovia being part of the first irradiation of archegosauroid to Gondwana or with konzhukovia originated on Gondwana and migrated to Laurasia, where the derivated species evolved. Besides, the fact that Konzhukovia belongs to a basal family to Stereospondyli reinforces the hypothesis that these ones are originated and diversificated in the West of Gondwana before the end of Permian. However, it is unlikely the hypothesis that the Stereospondyli may have stayed in a refuge in the East of Gondwana and may have diversificated after the great extinction in the end of Paleozoic period.

Les ostracodes, microcrustacés (Arthropoda), sont relativement abondants dans les archives paléontologiques. Sensibles aux variations paléoenvironnementales, la composition des assemblages et leur diversité sont d’excellents marqueurs des changements qui affectent le benthos marin néritique. Leur diversité est connue pour être fortement affectée par la crise biologique marquant la limite Permien-Trias, mais leur histoire à la fin du Permien moyen reste peu documentée.Près de 10 Ma avant la limite Permien-Trias, à la fin du Permien moyen, un important épisode d’extinction intervient, préfigurant le déclin de la biodiversité à la fin du Paléozoïque.L’étude systématique des échantillons prélevés le long des coupes de Chaotian (province du Sichuan, Chine) et de Penglaitan (province du Guangxi, Chine) a permis l’identification de 115 espèces d’ostracodes, dont 7 nouvelles. Le travail réalisé sur ces coupes constitue la toute première étude des événements de la fin du Permien moyen et du début du Permien supérieur s’appuyant sur l’observation des assemblages d’ostracodes. L’état de conservation des carapaces d’ostracode, étudié lors de ce travail, enregistre les effets de la fin d’un épisode de régression et le début d’un épisode de transgression au sommet du Permien moyen à Penglaitan. Les résultats s’avèrent en accord avec les données lithologiques et paléontologiques présentées dans la littérature, un modèle de reconstitution paléoenvironnementale basé sur les données de préservation des ostracodes est proposé.Une analyse critique de la qualité du jeu de données a permis d’évaluer l’influence des biais d’échantillonnage sur la représentativité du matériel fossile dans les études sur la paléobiodiversité et la paléoécologie. Les biais peuvent être corrigés par un traitement méthodologique approprié qui rend valide la comparaison des données de biodiversité. La richesse générique et spécifique décroît sensiblement au cours du Capitanien. Le passage du Permien moyen au Permien supérieur enregistre une augmentation de la richesse spécifique, malgré une faible diversité générique. L’ordre des Palaeocopida apparait ici affecté par une baisse de diversité générique et spécifique au Wuchiapingien inférieur. Si ces résultats ne permettent pas pour l’iPermiannstant de caractériser un événement global de renouvellement des communautés d’ostracodes, l’étude de matériel fossile provenant d’autres régions du monde permettra de définir l’ampleur des phénomènes observés. / Ostracods, microcrustaceans (Arthropoda), are quite abundant in the fossil record. Highly dependent to palaeoenvironmental conditions, their diversity and the assemblages’ composition are good indicators of changes affecting neritic marine benthos. Ostracods are known to be deeply affected by the Permian-Triassic crisis, but their history is poorly documented for the end of Middle Permian.About10 My before the Permian-Triassic boundary, the end of Middle Permian is characterized by a major extinction episode, which could be the first step of end-Palaeozoic biodiversity drop.Systematic study carried out on Chaotian section (Sichuan Province, P.R. China) and the Penglaitan section (Guangxi Province, P.R. China) samples allowed the identification of 115 species, including seven new species. The work carried out on these two sections provides the first study of end-Middle Permian extinction event, based on the observation of ostracod assemblages.Study of carapace preservation at Penglaitan section, highlighted the end of a regression phase and the beginning of a transgression phase at the top of Middle Permian. These results are relevant with lithologic and palaeontological data from literature. Thus, a palaeoenvironmental reconstruction model has been proposed, based on ostracod preservation data.An estimation of sampling bias consequences on fossil dataset representativeness in palaeobiodiversity and palaeoecology studies was realised. These biases could be corrected by an appropriate methodology allowing comparisons of biodiversity datum. Biodiversity data reveals a decrease of generic and specific richness during Capitanian. Specific richness increased passing the Middle-Upper Permian boundary. Palaeocopida order seems here affected by a generic and specific richness decline at basal Wuchiapingian. If these results do not allow for the time being to characterize a global ostracod turnover, further studies on material from other regions in the world will allow defining the extent of the observed phenomena.

As análises palinológicas desenvolvidas no Estado do Rio Grande do Sul estiveram, em sua maioria, relacionadas ao estudo das jazidas de carvão, resultando no reconhecimento de associações palinológicas vinculadas estreitamente às paleoturfeiras. Como resultado, o conhecimento das demais associações palinológicas permianas é menos detalhado, com efeito na compartimentação palinobioestratigráfica da Bacia do Paraná, tornando-se necessário aprimorar os limites das biozonas estabelecidas e compreender o melhor significado da sucessão bioestratigráfica. Esta tese compreende a análise palinológica dos poços HN-05-RS e HN-25-RS e de um afloramento localizados na região de Candiota – Hulha Negra, sul do Rio Grande do Sul. Um total de oito amostras foi coletado no afloramento (formações Rio Bonito e Palermo), enquanto 114 são referentes a amostras de subsuperfície, envolvendo o intervalo entre o Subgrupo Itararé à Formação Rio do Rasto. A análise palinológica permitiu a identificação de 143 espécies, incluindo esporos (64), grãos de pólen (67) e elementos microplanctônicos (12). As características qualitativas e quantitativas das associações recuperadas nos dois poços permitiram a proposição de três zonas de associação, designadas como: (i) Zona Granulatisporites austroamericanus – Vittatina saccata (GV), ocorrente entre o Subgrupo Itararé e topo da Formação Rio Bonito; (ii) Zona Lundbladispora braziliensis – Weylandites lucifer (LW), entre o topo da Formação Rio Bonito/base da Formação Palermo à porção média desta última; e (iii) Zona Thymospora thiesseni – Lueckisporites virkkiae (TL), entre a porção média da Formação Palermo à base da Formação Rio do Rasto. As distribuições dos táxons em cada uma dessas unidades são distintas das amplitudes apresentadas para a Bacia do Paraná em território brasileiro e encontram maiores similaridades com o zoneamento do norte do território uruguaio, de idades coevas. Na Bacia do Paraná, as zonas GV e LW são correlatas, grosso modo, à Zona V. costabilis, enquanto a Zona TL é correspondente à Zona L. virkkiae, ainda que divergências nos táxons tenham sido observadas. Por outro lado, as zonas GV, LW e TL são muito semelhantes às zonas estabelecidas no Uruguai, Cristatisporites inconstans – Vittatina subsaccata, de Intervalo de Lundbladispora e Striatoabieites anaverrucosus – Staurosaccites cordubensis, respectivamente, ainda inéditas. Adicionalmente, uma nova idade radiométrica foi obtida para a Formação Rio Bonito no afloramento estudado, onde foram reconhecidas as zonas de idade permiana V. costabilis (níveis C1 a C3, relativos ao topo da Formação iii Rio Bonito) e L. virrkiae (C4 a C8, correspondentes ao topo da Formação Rio Bonito à base da Formação Palermo). A idade de 281,4 ± 3,4 Ma é interpretada como a base da Zona Lueckisporites ou topo da Zona GV, conforme o conteúdo palinológico nas camadas acima e abaixo do nível de tonstein utilizado na datação. Ao confrontar esta datação absoluta com outras selecionadas para a bacia, o posicionamento das biozonas é proposto como segue: (i) Zona Granulatisporites austroamericanus – Vittatina saccata, entre o Asseliano à porção média do Artinskiano; (ii) Zona Lundbladispora braziliensis – Weylandites lucifer, Artinskiano Médio; e (iii) Zona Thymospora thiesseni – Lueckisporites virkkiae, datada como Artinskiano Médio/Superior ao Wordiano. / Mostly of the palynological analysis carried out in Rio Grande do Sul State is related to the study of the coal seams, which resulted in the recognition of palynological associations closely linked to swampy paleoenvironments. As result, other Permian palynogical associations are poorly defined, affecting the palynostratigraphic scheme developed to the Paraná Basin, which implies in necessities on improvement of the limits of those biozones and the better understanding on the meaning of the biostratigraphical succession. This thesis involves palynological studies on the HN-05-RS and HN-25-RS boreholes and one outcrop all located in Candiota – Hulha Negra region, southern Rio Grande do Sul. Eight samples was collected in the ouctcrop (corresponding to Rio Bonito and Palermo formations), while 114 samples corresponds to subsurface, related to the interval between the Itararé Subgroup and Rio do Rasto Formation. The palynological analysis allowed the recognition of 143 species among spores (64), pollen grains (67) and microplanktonic elements (12). The quantitative and qualitative aspects of the recovered associations in the boreholes enable the proposition of three association biozones, designated as: (i) Granulatisporites austroamericanus - Vittatina saccata Zone (GV), occurring between the Itararé Subgroup and topmost deposits of the Rio Bonito Formation, (ii) Lundbladispora braziliensis - Weylandites lucifer Zone (LW), from the top of Rio Bonito/base of the Palermo Formation to the middle portion of this last unit, and (iii) Thymospora thiesseni - Lueckisporites virkkiae Zone (TL), which occurs between the middle portion of Palermo-Formation to the base of Rio do Rasto Formation. The distribution of some taxa in each of these units are distinct from the know ranges presented to the Paraná Basin in the brazilian portion, and record more similarities with the biozone of northern Uruguay, of coeval ages. In the Paraná Basin, the GV and LW zones are roughly correlated to Zone V. costabilis, while the TL Zone corresponds to the L. virkkiae Zone, although differences in the taxa have been observed. Otherwise, the GV, LW and TL zones are very similar to the Uruguayan biozones, such as Cristatisporites inconstans - Vittatina subsaccata, Interval of Lundbladispora and Striatoabieites anaverrucosus - Staurosaccites cordubensis, respectively, although these are still unpublished. Moreover, a new radiometric age was obtained for the Rio Bonito Formation in the outcrop studied, in which was recognized the Permian biozones V. costabilis Zone ( C1-C3 levels, related to the topmost deposits of the Rio Bonito Formation) and L. virkkiae Zone (C4-C8 levels, between the topmost v Rio Bonito Formation and basal portion of the Palermo Formation). The age of 281.4 ± 3.4 Ma is interpreted as the base of Lueckisporites Zone or top of the GV Zone, according to the palynogical content related to the nearest layers of the tonstein used on the dating. Comparing this new absolute age with other selected datings for the basin, the positioning of biozones is proposed as follows: (i) Granulatisporites austroamericanus - Vittatina saccata Zone between the Middle Asselian to the Artinskian, (ii) Lundbladispora braziliensis - Weylandites lucifer Zone, Middle Artinskian, and (iii) Thymospora thiessen - Lueckisporites virkkiae Zone as Middle/Upper Artinskian to Wordian.

The late Permian Queen Formation (115 m thick) is a succession of mixed clastics, carbonates and evaporites deposited in the northeastern margin of Central Basin Platform of the Permian Basin, west Texas, USA. Depositional facies, stacking patterns of cyclic facies associations and statistical correlation of rock property variations define geologic controls on reservoir rock properties. Textural, compositional, petrophysical and diagenetic variations within lithofacies exhibit systematic changes with stratigraphic position, which can be related to base level changes that were controlled by high-frequency, low-amplitude, sea level fluctuations during a greenhouse period. Ten lithofacies record variations in clastic input, shallow marine carbonate production, and evaporate precipitation in sabhkas and salinas. Four different types of lithofacies associations define: (1) transgressive deltaic deposits; (2) upward-shallowing evaporite and carbonate tidal-flat deposits; (3) transgressive beach ridge and sand flat deposits; and (4) upward-shallowing evaporite salina-sabhka deposits. Stacking patterns of lithofacies associations define sixteen depositional cycles that can be grouped into eight cycle sets. Cycle sets in turn are grouped to define two high-frequency sequences. Sequence 1 progresses from fluvial to carbonate tidal flat cycles. Sequence 2 consists of salina-dominated upward-shoaling cycles. Lateral continuity of cycles indicates restricted sedimentation on low-accommodation inner platform areas updip of prograding highstand platform-margin carbonate buildups, and a long-term trend of accommodation decrease. The Queen Formation contains two reservoir types; (1) siliciclastic reservoirs capped by evaporites and (2) layer-cake carbonate reservoirs. Of the four reservoir zones identified, R11 in lowstand fluvial-deltaic deposits has relatively little cement and the best reservoir characters.

Numerous recent studies have demonstrated the importance of syndepositional faulting as an inherent element of steep-rimmed carbonate margins. However, these studies have not emphasized the relationship to older shelf margins, multiphase deformation history, and complexity of fault zone internal structure. In the Guadalupe Mountains, New Mexico, extensive syndepositional deformation parallels the Permian Capitan shelf margin reef and has developed in the absence of regional tectonic forces due to a combination of early carbonate cementation, gravitational instability, differential compaction, and variable progradation to aggradation at pre-existing shelf margins. This study focuses on the geometry, growth history, and internal fill type distribution within the Cave Graben Fault System (CGFS) in Slaughter and Rattlesnake Canyons of the Guadalupian (Capitan) shelf margin with the intent to understand the temporal and spatial evolution of deformation in front of the G24 shelf margin. Stratigraphy, faults and fractures exposed within the CGFS were mapped using high-resolution gigapan photos and GPS, along with RCRL Guadalupe airborne lidar, provides a geospatial database for 3D visualization, quantification, and interpretation. Detailed mapping reveals a high degree of variability in fault geometry, including the presence of vertical and lateral fault relays, antithetic and synthetic splays, and highly variable fault and fracture apertures, suggesting a complex deformational history. Hundreds of early-formed fractures have been mapped within the G24-G25 shelf margin system, but the development of significant faults with appreciable displacement only occurs in front of the G24 margin. Vertical fault displacement varies from 9 to 34 m in the CGFS. Breccias several meters in width fill the main faults and contain entrained sediment and clasts of variable age and composition. Stratal geometries reveal that movement and episodic growth occurred along the faults soon after deposition. Further investigation of the sediment and breccia fills suggests that a significant dissolution event along the fault allowed for the entrainment of much younger, post-Permian sediment. Based on these findings it appears that in Rattlesnake Canyon at least 30-60% of the CGFS vertical displacement occurs in the Permian, whereas up to 40-70% may develop post-Permian, providing a significant advancement in the understanding of timing of fault systems within the Capitan shelf margin. / text

No description available.

No description available.