Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 81-85).

Thèse (Ph. D.) -- Université Laval, 1998. / Bibliogr.: f. [254]-278. Publié aussi en version électronique.

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: William L. Fisher. Vita. Includes bibliographical references.

A investigação foi realizada no extremo sul do Brasil, nos derrames básicos da Formação Serra Geral, entre os municípios de Santa Cruz do Sul-Herveiras e Lajeado. Na área estão expostas sucessões de derrames baixo Ti com morfologias pahoehoe e rubbly, pertencentes a Província Ígnea Paraná-Etendeka. Na sequência de derrames em Santa Cruz do Sul-Herveiras foram identificadas 16 litofácies e três associações de litofácies 1- pahoehoe composta inicial, 2- pahoehoe simples inicial e 3- rubbly simples tardia. Nos derrames pahoehoe compostos (< 1m espessura), o rápido resfriamento permitiu a geração de pipe vesículas e vesículas V1. Nos derrames pahoehoe simples (2-6 m de espessura), uma grande quantidade de estruturas de segregação foi gerada: proto-cilindros e cilindros; pods; camadas de vesículas S1 e S2 e camadas de cilindros; pipes, vesículas V1 e gigantes. Nos derrames rubbly (> 30m espessura), apenas vesículas tipo V1 e gigantes são preservadas. Estudos petrográficos indicaram que os processos de dissolução de cristais e liberação de gás originaram porosidades primárias, enquanto processos de alteração e fraturamento geraram uma grande quantidade de porosidades secundárias. No entanto, a precipitação de minerais secundários nos poros tende a reduzir o espaço disponível para armazenamento de fluidos, demonstrando que apenas a existência de poros é insuficiente para a existência de um reservatório vulcânico. Geoquimicamente, todos os derrames estudados podem ser classificados como do tipo Gramado. As composições variam de basaltos a andesito basálticos de afinidade toleítica nos perfis Santa Cruz e Lajeado, enquanto na área do Morro da Cruz, os derrames do tipo ponded pahoehoe exibem composições de andesitos. A assimilação crustal sugerida para estas sequências vulcânicas permite explicar as altas razões isotópicas iniciais de Sr (0,707798–0,715751), e os valores baixos de Nd (-8,36 a -5,41), com associadas variações isotópicas de Pb (18,42 <206Pb/204Pb< 18,86; 15,65 <207Pb/204Pb< 15,71; 38,62 <208Pb/204Pb< 39,37). A evolução magmática dos derrames básicos de Santa Cruz do Sul-Herveiras e Lajeado iniciou com o armazenamento de líquidos máficos durante um curto período em câmaras magmáticas rasas, associados a um processo de contaminação crustal significativo, o qual permitiu a ascensão de magmas com composição de olivina basaltos, os quais exibem morfologia pahoehoe composta em superfície. A contínua cristalização fracionada dentro da câmara magmática concomitante com assimilação em graus variáveis de distintos contaminantes com idades Paleoproterozoica e Neoproterozoica, somada a uma contribuição significativa de recarga de magma permitiu a ascensão de magma com composição andesito basáltica, o qual exibe morfologia pahoehoe simples em superfície. A contínua recarga de magma na câmara magmática concomitante a graus mais elevados de assimilação levaram a formação de lavas andesito basálticas com assinaturas isotópicas mais contaminadas e que exibem na superfície morfologia rubbly pahoehoe. Processos de diferenciação dos líquidos concomitantes as maiores taxas de assimilação de distintos contaminantes durante um período prolongado em um câmara magmática rasa, a qual é distinta daquela onde os magmas de Santa Cruz do Sul-Herveiras e Lajeado estavam armazenados, favoreceu a formação dos andesitos do Morro da Cruz, que exibem as assinaturas mais contaminadas da ombreira sul da Sinclinal de Torres. / This study was performed in the southern Brazil, in the basic lava flows of the Serra Geral Formation, between the localities of Santa Cruz do Sul- Herveiras and Lajeado. Low Ti lava flow successions with pahoehoe and rubbly morphologies occur in the study area, which belong to Paraná-Etendeka Igneous Province. In the volcanic sequence of the Santa Cruz do Sul-Herveiras, the basaltic lava flows were divided into 16 lithofacies and grouped into three lithofacies associations: 1- early compound pahoehoe, 2- early simple pahoehoe, and 3- late simple rubbly. In the compound pahoehoe lava flows (< 1m thickness), the fast cooling allowed the generation of pipe vesicles and V1- type vesicles. In the simple pahoehoe lava flows (2-6 m thickness), a large amount of segregation structures were generated: proto-cylinder, cylinder, pods, S1 and S2-type vesicle sheets, pipe vesicles, V1-type and giant vesicles. In the rubbly pahoehoe lava flows (> 30 m thickness), just V1-type and giant vesicles are preserved. Petrographic studies indicate that the dissolution of deuteric crystals and gas releasing processes formed the primary porosities, while processes such as alteration and fracturing generated the secondary porosities. However, the precipitation of secondary minerals in vesicles and cavities decreases the available space for fluid storage, which suggest that the existence of pores alone is insufficient for creating volcanic reservoirs. Geochemically, all the studied lava flows could be classified in the Gramado type. The geochemical compositions in the Santa Cruz do Sul-Herveiras and Lajeado profiles range from basalt to basaltic andesites with tholeiitic affinity, while in the Morro da Cruz area, the ponded pahoehoe lava flows exhibit andesite compositions. The process of crustal assimilation suggested for these volcanic sequences allow explains the high and widespread initial Sr isotopic ratios at 0.707798–0.715751 and the low εNd at −8.36 to −5.41, with associated Pb isotopic variations (18.42 < 206Pb/204Pb < 18.86; 15.65 < 207Pb/204Pb <15.71; 38.62 < 208Pb/204Pb < 39.37). The magmatic evolution of the SCSH and LJ basic lava flows begins with the storage of mafic liquids during a short period at shallow-level magma chamber, associated to significant crustal contamination that allowed the magma ascent with composition of olivine basalts that exhibit compound pahoehoe morphology at surface. The continuous fractional crystallization within the magma chamber coupled with variable assimilation degrees of distinct contaminants with Paleoproterozoic and Neoproterozoic ages, in addition to significant contribution of magma recharge led to magma ascent with basaltic andesite composition that display at surface the simple pahoehoe morphology. The continuous magma recharge in the magma chamber coupled with higher assimilation degree allowed the formation of basaltic andesite lavas with more contaminated isotopic signatures that exhibit rubbly morphology at the surface. Differentiation process of liquids coupled with the highest assimilation degrees of distinct contaminants during longer time in a shallow-level magma chamber, which is distinct from that where SCSH and LJ magmas have been stored, led to formation of andesites of the Morro da Cruz that exhibit the most contaminated isotopic signatures of south hinge of the Torres Syncline.

Orientador : Prof. Dr. Fernando Farias Vesely / Coorientador : Prof. Dr. Paulo Alves de Souza / Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Terra, Programa de Pós-Graduação em Geologia. Defesa: Curitiba, 10/04/2014 / Inclui referências : f. 99-116 / Área de concentração: Geologia exploratória / Resumo: O presente trabalho apresenta resultados do estudo palinológico de estratos da porção inferior do Grupo Itararé em sete afloramentos da região de Porto Amazonas, Lapa e Campo do Tenente, localizados no sudeste do estado do Paraná. Nos afloramentos analisados foram individualizadas nove fácies principais que incluem diamictitos, arenitos, ritmitos e pelitos relacionados a um ambiente marinho glácio-influenciado e dominado por fluxos gravitacionais de sedimentos. Foram reconhecidas nas amostras coletadas cinco espécies de esporos, 10 de pólen monossacados e um de pólen bissacado, considerados contemporâneos à sedimentação. Dentre os gêneros estudados, pelo menos um é inédito na Bacia do Paraná, Densipollenites Bharadwaj, 1962. Foram também identificadas 31 espécies retrabalhadas incluindo esporos trilete, criptoesporos, prasinofíceas, clorofíceas, acritarcos, quitinozoários e escolecodontes, comuns em associações que vão do Eosiluriano ao Eocarbonífero. O reexame de afloramentos considerados anteriormente como de rochas devonianas mostrou que parte do seu conteúdo palinofossilífero contém palinomorfos Neo-Carboníferos, considerados contemporâneos a sedimentação. Não permitindo, portanto, inferir registros glaciais neodevonianos nessa porção da bacia. O predomínio de grãos de pólen monossacados e a ausência de grãos de pólen teniados, assim como a ocorrência de palinomorfos retrabalhados, são elementos diagnósticos que permitem posicionar o intervalo estudado no Carbonífero (Zona Ahrensisporites cristatus). O intervalo de Porto Amazonas, situado na porção norte da área estudada é caracterizado pela presença de raros grãos de pólen monossacados (Cannanoropolis, Caheniassacites e Potoniesporites) e predomínio de palinomorfos retrabalhados, enquanto na região de Lapa e Campo do Tenente ocorre um incremento na quantidade de grãos de pólen monossacados. Palavras chaves: Palinologia, Grupo Itararé, glaciações gondwânicas / Abstract: This dissertation presents the results of a palinological investigation carried out on the lower part of the Itararé Group by seven outcrops located in Porto Amazonas, Lapa and Campo do Tenente, southeastern Paraná State. The studied outcrops comprise nine sedimentary facies including diamictites, sandstones, rhythmites and mudstones deposited in glacially influenced marine environments via gravity flows. There were identified five species of spores, 10 species of monosaccate pollens and one specimen of bisaccate pollen, all considered indigenous. Among these, Densipollenites (Bharadwaj 1962) is described for the first time in the Paraná Basin. In addition, it was possible to recognize 31 reworked species, including trilete spores, criptospores, prasinophyceae, chlorophyceae, acritarch, chitinozoa, and scolecodonts, which are common in associations ranging in age from the Neosillurian to the early Carboniferous. The reexamination of outcrops previously considered as Devonian rocks allowed to conclude that the Devonian palynomorphs are actually the product of reworking because they occur associated with younger fossils. As a result, a supposed late Devonian glaciation in this part of the basin is not supported. The dominance of monosaccate pollens and the absence of teniate pollens, as well as the occurrence of reworked palynomorphs are diagnostic elements allowing to place the entire studied interval in the Carboniferous (Ahrensisporites cristatus Zone). The strata of Porto Amazonas, in the northern reach of the studied area and characterized by monosaccate pollens (Cannanoropolis, Caheniassacites and Potoniesporites) and the dominance of reworked palynomorphs, while in the region of Lapa and Campo do Tenente is an increase in pollen grains monossacados. Key words: Palynology, Itarare Group, Gondwana glaciations.

Orientador: Mario Luis Assine / Banca: Rosemarie Rohn Davies / Banca: Almério Barros França / Resumo: A Formação Rio Bonito é a unidade inferior do Grupo Guatá, Eopermiana da Bacia do Paraná. Compreende, da base para o topo, os membros Triunfo, Paraguaçu e Siderópolis. No Estado do Paraná, a espessura da Formação Rio Bonito diminui para norte, principalmente em conseqüência do adelgaçamento e acunhamento do Membro Triunfo, que desaparece no sul do Estado de São Paulo. Para investigar estas variações de espessura e de fácies na Formação Rio Bonito, foi escolhida uma área no nordeste do Estado do Paraná onde a unidade apresenta bons afloramentos e poços para correlação, além de existirem importantes ocorrências de carvão. Para atingir os objetivos propostos, foram levantados perfis estratigráficos verticais e confeccionadas seções estratigráficas, levantados dados de paleocorrentes, caracterizadas associações de fácies sedimentares, correlacionados dados de superfície com os de perfis de poços, interpretados os paleoambientes de sedimentação e comparado o empilhamento estratigráfico da área estudada com o de áreas adjacentes. Cinco associações de fácies foram caracterizadas, permitindo constatar que a parte inferior da Formação Rio Bonito no nordeste do Estado do Paraná apresenta espessuras variáveis por ser o produto de preenchimento sedimentar uma sobre superfície deposicional irregular. Devido à existência de paleovales na superfície do topo do Grupo Itararé, de estruturas sedimentares produzidas por correntes de maré e de paleocorrentes bipolares para norte e sul, a parte inferior da Formação Rio Bonito foi interpretada como produto de preenchimento de vales incisos por depósitos aluviais e de canais de maré (associações de fácies 1 e 2, Membro Triunfo), sobrepostos retrogradacionalmente por lamitos e arenitos de canais de maré da zona central do estuário (associação de fácies 3)...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Rio Bonito Formation is the lowermost unit of the Guatá Group, Early Permian of the Paraná Basin. It comprises from the bottom to the top, the Triunfo, Paraguaçu and Siderópolis Members. In the State of Paraná, the thickness of the Rio Bonito Formation decreases northwards, mainly because of the thinning and wedging out of the Triunfo Member, which disappears in the south of the State of São Paulo. To investigate thickness and facies variations in the Rio Bonito Formation, an area in the northeast of the State of Paraná was chosen wherein the unit presents good outcrops and wells for correlation, besides the existence of important coal beds. To reach the proposed objectives, vertical stratigraphic profiles and stratigraphic sections were made, paleocurrents data were obtainded, sedimentary facies were characterized, correlation between surface and well profile data were performed, sedimentation paleoenvironments were interpreted and the local stratigraphic succession correlated with adjacent areas. Five facies associations were characterized, being possible to observe that the thickness variations of the Rio Bonito Formation in the northeast of the State of Paraná resulted from sedimentation on an irregular depositional surface. Due to the existence of paleovalleys and the sedimentary structures produced by tide currents and bipolar paleocurrents towards the north and south, the lower portion of the Rio Bonito Formation was interpreted as a product of incised-valleys filled-up by estuarine alluvial and tidal channels deposits (facies associations 1 and 2, Triunfo Member). The succession is retrogradational and the basal section is overlayed by mudstones and sandstones of tidal-channels from the innermost portion of the estuary (facies association 3)...(Complete abstract click electronic access below) / Mestre

A investigação foi realizada no extremo sul do Brasil, nos derrames básicos da Formação Serra Geral, entre os municípios de Santa Cruz do Sul-Herveiras e Lajeado. Na área estão expostas sucessões de derrames baixo Ti com morfologias pahoehoe e rubbly, pertencentes a Província Ígnea Paraná-Etendeka. Na sequência de derrames em Santa Cruz do Sul-Herveiras foram identificadas 16 litofácies e três associações de litofácies 1- pahoehoe composta inicial, 2- pahoehoe simples inicial e 3- rubbly simples tardia. Nos derrames pahoehoe compostos (< 1m espessura), o rápido resfriamento permitiu a geração de pipe vesículas e vesículas V1. Nos derrames pahoehoe simples (2-6 m de espessura), uma grande quantidade de estruturas de segregação foi gerada: proto-cilindros e cilindros; pods; camadas de vesículas S1 e S2 e camadas de cilindros; pipes, vesículas V1 e gigantes. Nos derrames rubbly (> 30m espessura), apenas vesículas tipo V1 e gigantes são preservadas. Estudos petrográficos indicaram que os processos de dissolução de cristais e liberação de gás originaram porosidades primárias, enquanto processos de alteração e fraturamento geraram uma grande quantidade de porosidades secundárias. No entanto, a precipitação de minerais secundários nos poros tende a reduzir o espaço disponível para armazenamento de fluidos, demonstrando que apenas a existência de poros é insuficiente para a existência de um reservatório vulcânico. Geoquimicamente, todos os derrames estudados podem ser classificados como do tipo Gramado. As composições variam de basaltos a andesito basálticos de afinidade toleítica nos perfis Santa Cruz e Lajeado, enquanto na área do Morro da Cruz, os derrames do tipo ponded pahoehoe exibem composições de andesitos. A assimilação crustal sugerida para estas sequências vulcânicas permite explicar as altas razões isotópicas iniciais de Sr (0,707798–0,715751), e os valores baixos de Nd (-8,36 a -5,41), com associadas variações isotópicas de Pb (18,42 <206Pb/204Pb< 18,86; 15,65 <207Pb/204Pb< 15,71; 38,62 <208Pb/204Pb< 39,37). A evolução magmática dos derrames básicos de Santa Cruz do Sul-Herveiras e Lajeado iniciou com o armazenamento de líquidos máficos durante um curto período em câmaras magmáticas rasas, associados a um processo de contaminação crustal significativo, o qual permitiu a ascensão de magmas com composição de olivina basaltos, os quais exibem morfologia pahoehoe composta em superfície. A contínua cristalização fracionada dentro da câmara magmática concomitante com assimilação em graus variáveis de distintos contaminantes com idades Paleoproterozoica e Neoproterozoica, somada a uma contribuição significativa de recarga de magma permitiu a ascensão de magma com composição andesito basáltica, o qual exibe morfologia pahoehoe simples em superfície. A contínua recarga de magma na câmara magmática concomitante a graus mais elevados de assimilação levaram a formação de lavas andesito basálticas com assinaturas isotópicas mais contaminadas e que exibem na superfície morfologia rubbly pahoehoe. Processos de diferenciação dos líquidos concomitantes as maiores taxas de assimilação de distintos contaminantes durante um período prolongado em um câmara magmática rasa, a qual é distinta daquela onde os magmas de Santa Cruz do Sul-Herveiras e Lajeado estavam armazenados, favoreceu a formação dos andesitos do Morro da Cruz, que exibem as assinaturas mais contaminadas da ombreira sul da Sinclinal de Torres. / This study was performed in the southern Brazil, in the basic lava flows of the Serra Geral Formation, between the localities of Santa Cruz do Sul- Herveiras and Lajeado. Low Ti lava flow successions with pahoehoe and rubbly morphologies occur in the study area, which belong to Paraná-Etendeka Igneous Province. In the volcanic sequence of the Santa Cruz do Sul-Herveiras, the basaltic lava flows were divided into 16 lithofacies and grouped into three lithofacies associations: 1- early compound pahoehoe, 2- early simple pahoehoe, and 3- late simple rubbly. In the compound pahoehoe lava flows (< 1m thickness), the fast cooling allowed the generation of pipe vesicles and V1- type vesicles. In the simple pahoehoe lava flows (2-6 m thickness), a large amount of segregation structures were generated: proto-cylinder, cylinder, pods, S1 and S2-type vesicle sheets, pipe vesicles, V1-type and giant vesicles. In the rubbly pahoehoe lava flows (> 30 m thickness), just V1-type and giant vesicles are preserved. Petrographic studies indicate that the dissolution of deuteric crystals and gas releasing processes formed the primary porosities, while processes such as alteration and fracturing generated the secondary porosities. However, the precipitation of secondary minerals in vesicles and cavities decreases the available space for fluid storage, which suggest that the existence of pores alone is insufficient for creating volcanic reservoirs. Geochemically, all the studied lava flows could be classified in the Gramado type. The geochemical compositions in the Santa Cruz do Sul-Herveiras and Lajeado profiles range from basalt to basaltic andesites with tholeiitic affinity, while in the Morro da Cruz area, the ponded pahoehoe lava flows exhibit andesite compositions. The process of crustal assimilation suggested for these volcanic sequences allow explains the high and widespread initial Sr isotopic ratios at 0.707798–0.715751 and the low εNd at −8.36 to −5.41, with associated Pb isotopic variations (18.42 < 206Pb/204Pb < 18.86; 15.65 < 207Pb/204Pb <15.71; 38.62 < 208Pb/204Pb < 39.37). The magmatic evolution of the SCSH and LJ basic lava flows begins with the storage of mafic liquids during a short period at shallow-level magma chamber, associated to significant crustal contamination that allowed the magma ascent with composition of olivine basalts that exhibit compound pahoehoe morphology at surface. The continuous fractional crystallization within the magma chamber coupled with variable assimilation degrees of distinct contaminants with Paleoproterozoic and Neoproterozoic ages, in addition to significant contribution of magma recharge led to magma ascent with basaltic andesite composition that display at surface the simple pahoehoe morphology. The continuous magma recharge in the magma chamber coupled with higher assimilation degree allowed the formation of basaltic andesite lavas with more contaminated isotopic signatures that exhibit rubbly morphology at the surface. Differentiation process of liquids coupled with the highest assimilation degrees of distinct contaminants during longer time in a shallow-level magma chamber, which is distinct from that where SCSH and LJ magmas have been stored, led to formation of andesites of the Morro da Cruz that exhibit the most contaminated isotopic signatures of south hinge of the Torres Syncline.

>Magister Scientiae - MSc / The Bredasdorp Basin was formed consequent to extensional episodes during the initial stages of rifting in the Jurassic age. The basin acted as a local depocentre and was primarily infilled with late Jurassic and early Cretaceous shallow-marine and continental sediments. Two wells namely; D-D1 and E-AP1 were studied in order to evaluate the petrophysics and characterize sandstone reservoirs of the western Bredasdorp basin. This could be achieved by generating and comparing results from core analysis and wireline in order to determine if the two wells are comprised of good quality sandstone reservoirs and if the identified reservoirs produce hydrocarbons. A number of methods were employed in order to characterise and evaluate sandstone reservoir, these included; editing and normalization of raw wireline log data ,classification of lithofacies on the basis of lithology, sedimentary structures, facies distribution, grain size variation, sorting of grains, fossils and bioturbation; calibration of log and core data to determine parameters for petrophysical interpretation; volume of clay; determination of porosity, permeability and fluid saturation, cut-off determination to distinguish between pay and non-pay sands. Borehole D-D1 is located in the western part of the Bredasdorp Basin. Only two reservoirs in well D-D1 indicated to have pay parameters with an average porosity ranging from 11.3% to 16%, average saturation from 0.6% to 21.5% and an volume of clay from 26.5% to 31.5%. This well was abandoned due to poor oil shows according to the geological well completion report. On the contrary well E-AP1 situated in the northwestern section of the basin showed good quality reservoir sandstones occurring in the 19082m to 26963m intervals though predominantly water saturated. Pay parameters for all five reservoirs in this well showed zero or no average porosity, saturation and volume of clay.

The Vaal Reef placer is situated on the unconformable junction of the Strathmore and Stilfontein formations of the Johannesburg Subgroup. Within the South Division of the Vaal Reefs Exploration and Mining company lease, the Vaal Reef Placer is shown to be composed of several different units. Each unit exhibits its own specific characteristics and trend direction which can be used to establish distinct "Reef packages". These packages can be mapped in such a way as to provide a preliminary lithofacies map for the Vaal Reef Placer. The delineation of such geologically homogenous zones, and the development of a suitable depositional model, can be utilised in several ways. The characteristics of a particular zone are shown to influence the control of stoping width, evaluation of remnant pillars and the geostatistical methodology of evaluating current and future ore reserve blocks.

On the recent lobe of the Fraser River Delta, peat deposition is occurring in three distinct settings: the distal delta plain, the transitional upper delta to lower delta plain, and the upper delta plain to alluvial plain. Each de-positional setting contains a unique sequence of lithofacies and biofacies. Distal lower delta plain peats, although widespread, form a thin, discontinuous peat network dominated by a sedge-grass facies. The peats contain numerous intercalations of silt and silty clay, with a moderate to high pH and a high concentration of sulphur values. The peats overlie a thin fluvial sequence, which in turn overlies a thick coarsening upward sequence of prodelta clay and silty clay. Peats from this environment will form thin lenticular seams of high ash and high sulphur coal. The coal maceral precursors in the peat suggest that the base of the coal will be comprised mainly of desmocol1inite, whereas near the top of the seam oxyfusinite, macrinite, and interlaminated cutinite and vit-rodetrinite would be common. Initial lower delta plain-upper delta plain peats developed from interdistributary brackish marshes. High concentrations of sulphur and ash in these peats decreased in overlying freshwater sedge-grass facies as the delta prograded and the natural levees formed. Sphagnum dominated communities eventually succeeded in areas where fluvial influence was minimal. Laterally, however, along active channel margins, sedge-grass peats intercalate with silty clay overbank and sandy splay deposits. A thin fluvial unit of fining upward sand, silt and clay and a thick sequence of coarsening upward prodelta clay and silty clay underly the deposit. These peats will form relatively thick, widespread coal seams. The seams will be thin and possibly discontinuous adjacent to channels and areas where extensive splaying has occurred. High sulphur concentrations will be confined to the base of seams. The maceral precursors suggest that interbanded telenite, cu-tinite and cerenite will be abundant in the base of the seam and will grade vertically into suberinite, telocollinite, and telenite rich coal. Stumps which will form massive telenite will occur locally. Alluvial plain peats accumulated in freshwater backswamp environments. Earliest sedge-clay and gyttjae peats developed over thin fining upward cycles of silty sand, silt and clay and inter laminated silt, and silty clay of flood origin. Overlying sedge grass and Sphagnum peats are horizontally stratified and form sharp contacts with.bordering flood sediments, at active channel margins, sedge-grass peats intercalate with overbank silty clay to form well developed natural levees, these peats will form a thick seam of high quality coal. The microlithotype composition is comprised of vitritic carbar-gillites and liptites near the base of the seams, and will shift to a clarite and then primarily vitrite near the top. Compared to delta plain peats, maceral distribution will be less complex. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate