Thesis (Ph.D.)--University of Adelaide, Dept. of Geology, 2000? / At head of title: National Centre for Petroleum Geology and Geophysics. CD-ROM contains Appendices (1-10) in PDF. Includes copies of papers co-authored by the author. Includes bibliographical references (leaves [471]-499 in vol. 2).

Thesis (Ph. D.)--Carleton University, 1997. / Also available in electronic format on the Internet.

Thesis (Ph. D.)--Université Paul Sabatier, Toulouse III, 1975. / Map documentation: p. [I-II] (3rd set of capital Roman numerals). Includes bibliographical references (p. [I]-[XIX]).

A traverse through the Balfour Formation was chosen in the area around the towns of Fort Beaufort and Alice in the Eastern Cape Province. The main objectives of the study were to map the lithological variations within the Balfour Formation and to distinguish it from the underlying Middleton Formation and the overlying Katberg Formation. A combined desktop, field and laboratory approach was used in this study. Aerial photographs, satellite images and digital topographical maps formed the basis of the desktop work. After desktop mapping, a number of field traverses were measured through the study area. Sedimentary structures were observed, photomosaics were done, stratigraphic sections were measured and samples were collected for thin sectioning, heavy mineral separation and major, trace and REE analysis. Sedimentological development of the Balfour Formation has been outlined in relation to its provenance during the Late Permian. Lithological variation of the Balfour Formation is characterised by alternating sandstone-dominated and mudstone-dominated members. Arenaceous Oudeberg and Barberskrans Members are contain facies ranging from intraformational conglomerates (Gmm), massive sandstones (Sm & Ss), horizontally laminated sandstones (Sh), planar and trough cross-bedded sandstones (Sp, Sl & St), trough cross-laminated sandstones (Sr) and fine-grained sediments (Fm & Fl), whereas the mudstone dominated members are characterised by the facies Fm and Fl. Lithofacies together with bedforms observed in the Balfour Formation were used in architecturalelement analysis. Sandstone–rich members are dominated by channel fill elements such as LS, DA, SB, LA and CH, whereas the fine-grained component consists of mainly, FF iii element. The mudstone-dominated members contain FF, CS and LV elements, with LA, SB and CH in the subordinate sandstones. Petrography, geochemistry and palaeocurrent analysis indicated that the source of the Balfour Formation was to the south-east and the rocks had a transitional/dissected magmatic arc signature. This led to the postulation of the Karoo Basin to have developed in a retro-arc foreland basin where there was supralithospheric loading in the Cape Fold Belt due to a compressional regime initiated by the subduction of Palaeo-Pacific plate underneath the Gondwana plate. The tectonic loading was episodic with eight major paroxysms affecting the Karoo Supergroup. The Balfour Formation coincides with the fourth paroxysm, this paroxysm in turn consists of two third-order paroxysm that initiated the deposition of the Oudeberg and Barberskrans Members in low sinuosity streams. Each paroxysm was followed by a period of quiescence and these resulted in the deposition of the Daggaboersnek, Elandsberg and Palingkloof Members in meandering streams. Depositional environments were determined mainly from the sedimentary structures and 3D architecture of the rock types. Sandstone rich members were formed by seasonal and ephemeral high energy low sinuous streams whereas the fine-grained rich members were formed by ephemeral meandering streams. Palaeoclimates have been equated to the present temperate climates; they were semi-arid becoming arid towards the top of the Balfour Formation. This has been determined geochemistry (CIA), sedimentary structures and other rock properties like colour.

<p> Sedimentary structures, textures and fabric were studied in detail in eight turbidite greywacke beds from the Cloridorme Formation (Middle Ordovician), Gaspe, Quebec. The beds are exposed on the wave-cut platform near Grande Vallee and were traced for about two miles along the strike (276 degrees), which is parallel to the average current direction (274 degrees) as indicated by sole mark directions. </p> <p> The beds under study show the following systematic downcurrent changes along the strike from east to west: (i) Sole mark types show the following changes: (1) tool marks such as grooves, prod marks and isolated flute marks, to (2) longitudinal ridges, longitudinal ridges with overlapping flute, closely spaced flutes, to (3) poorly developed, shallow longitudinal ridges with occasional cuspate crossing bars, to (4) smooth bottom with occasional grooves. (ii) There is an increase in variance of sole mark directions without a large change in the mean direction in most beds, but the sole mark direction changes by nearly 90° as one of the beds is traced from east to west along the strike. (iii) Most of the beds are massive and are divided into two parts by a bedding joint. However, in the proximal region, if a bed is unusually thin, the bedding joint is absent and the bed shows slightly wavy, plane-laminated structure at places. (iv) Grain orientations are generally statistically non-significant in the upper massive part of the bed in the proximal region and significant in the rest of the bed. Significant grain orientations and graptolite orientations show large deviations from the sole in the distal region. Deviations increase towards the top of the bed. (v) The beds show a change from good grading to poor grading or slight reverse grading from the proximal to distal region. It is considered that the beds were deposited by low concentration, highly turbulent currents. Deposition of the beds took place in two distinct phases. First a 'quick' bed separated from the current was sheared extensively by the overflowing current and on consolidation formed the lower part of the bed. Later deposition in the proximal region from the upper part of the current and the part close to the tail was by settling of individual particles from the suspension. Separation and consolidation of another 'quick' bed in some cases formed the upper part of the beds in the distal region. </p> <p> The depositing currents produced a good vertical and lateral grain size grading in the proximal region, but poor vertical grading in the distal region due to the loss of coarse grains and possibly increased concentration of flocculated clay. Also, the turbidity currents tended to "meander" greatly on slowing down in the distal region. </p> / Thesis / Doctor of Philosophy (PhD)

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Typescript (Photocopy) Three maps, folded, in back cover pocket. Includes bibliography: leaves [22-24]

Les réservoirs clastiques sont constitués pour la plupart d'un agencement géométrique de plusieurs structures. Le but de ces travaux est de fournir une représentation volumétrique de ces différents objets afin de pouvoir reproduire la grande hétérogénéité des dépôts sédimentaires. Nous proposons une paramétrisation tridimensionnelle compacte des objets sédimentaires qui permet de représenter des géométries variées et qui fournit un espace curvilinéaire pour la modélisation des hétérogénéités internes des structures sédimentaires. Les modèles de corps géologiques sont définis par une représentation par frontières, chacune des frontières étant construite par une surface paramétrique déformable. La formulation mathématique utilisée pour construire les espaces paramétriques sont les B-Splines rationnelles non uniformes dites NURBS (pour Non Uniform Rational B-Splines). Chaque forme élémentaire est contrôlée par des règles de déformations afin de maintenir la géométrie et la cohérence des objets durant l'édition. Les modèles de structures sédimentaires sont appliqués à la simulation de chenaux et des structures qui y sont liées telles que les barres d'accrétion latérale. Ils servent alors de support pour réaliser des simulations de propriétés pétrophysiques qui suivent l'espace paramétrique particulier de chaque objet. Les modèles d'objets sédimentaires sont également appliqués dans le cadre de l'interprétation semi-automatique d'images géologiques en adaptant des méthodes classiques d'extraction de formes. Cette approche est appliquée sur des images satellites de chenaux alluviaux. Des résultats préliminaires sur des données de sismiques 3D sont également présentés / Most clastic deposits consist in geometric arrangements of several structures. The purpose of this work is to provide a volumetric representation of these objects in order to reproduce the high heterogeneity of the sedimentary deposits. These models are constructed to be flexible and compact in order to model the sedimentary formations at different scales. The sedimentary models are defined by a boundary representation ; each boundary is defined by a deformable parametric surface. The proposed parametrization is the Non Uniform Rational B-Spline (NURBS). Each elementary shape is controlled by deformation rules and has connection constraints with associated objects, in order to maintain the geometry and the consistency through editing. Sedimentary structure models are applied to channel simulation and to the construction of the related structures such as point bars. These structures are then used as framework for petrophysical property simulations. The models are also applied to semi-automatically interpret geological images by adapting classical shape extraction methods. This approach is applied on satellite pictures showing alluvial channels and some preliminary results on 3D seismic time slices are also presented

Orientador: Tânia Márcia Costa / Resumo: Os caranguejos chama-maré fazem parte de uma complexa rede de interações comportamentais. Os machos utilizam de múltiplos sinais para corte e atração de fêmeas ou para interações agonísticas com outros machos. Entre estes, estão a construção de estruturas sedimentares e mudanças na coloração corporal. Embora estudos tenham mostrado as funções comportamentais destes sinais, pouco se sabe de seus efeitos em resposta aos fatores ambientais, como por exemplo, a temperatura. Nós investigamos se a coloração, ou as estruturas sedimentares, as “cúpulas”, construídas pelos machos de Leptuca letptodactyla podem auxiliar na termorregulação. Em campo, a contagem de cúpulas, a temperatura das camadas internas das tocas, a temperatura corporal e o comportamento dos machos construtores e não construtores de cúpulas foram avaliados, assim como a taxa de aquecimento dos machos de diferentes padrões de cor sob a radiação incidente. Através da análise digital de imagens, diferentes métricas de cor foram utilizadas para quantificar como a coloração dos caranguejos altera de acordo com a temperatura corporal, ou entre construtores e não construtores de cúpulas. As cúpulas foram diretamente relacionadas com o aumento da temperatura do solo. As tocas com cúpulas apresentaram temperaturas mais amenas nas camadas superficiais (até 20 mm) do que as tocas sem cúpulas. Em relação a coloração, machos construtores tiveram menos tons de verde e maior brilho (%) em suas carapaças, enquanto apresentaram quel... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Dur At Talah sedimentary sequence, located at the southern side of the Sirt Basin in central Libya, is composed of 150 m thick of mainly siliciclastic rocks. The importance of this sequence is linked to the importance of the Sirt Basin as one of large hydrocarbon reservoirs in Libya. The sequence is also an excellent site for vertebrate fossils of Late Eocene, the age of the sequence. Previous studies, though very limited compared to the importance of this area, are focused on its paleontological content. Sedimentology received only scant attention before this project. This thesis is an outcrop based study in which the focus is given to the sedimentary and biogenic (trace fossils) structures, aiming at defining and interpreting depositional facies which building up the sequence. The study is mainly based on field data which are analyzed on the light of related published literature and on the comparison with modern sedimentary environments. Results of facies analysis have led to splitting the entire sequence into three genetically related intervals. The oldest, we called the New Idam Unit (around 80m), is composed of very fine sandstones to mudstones. New Idam Unit is unconformably overlain by the Sarir Unit (around 50m), composed of medium grained cross bedded sandstones (the lower 25-30 m) changes up to very coarse and microconglomeratic sandstone (the upper 20-30 m). Thus, the Sarir Unit is split into the lower Sarir Subunit and upper Sarir subunit. The New Idam Unit presents both classical and unusual sedimentary and biogenic indicators that attribute this unit to estuarine depositional environment. It starts with outer estuarine (the lower 35 m) and ends up with inner estuarine (the upper 45 m). Maximum flooding surface is located in between. Above this surface the fluvial indicators increase and tidal indicators decrease, thus providing clue for basinward (North) migration of the shoreline. The lower Sarir subunit which was previously interpreted as fluvial deposits, preserves multi-scale sedimentary structures that undoubtedly belong to tidal processes. This is especially evidenced at the lower part of the lower Sarir Subunit (LLS). Fluvial indications over dominates the tidal ones in the upper part of the lower Sarir (ULS). Due to this configuration the whole lower Sarir subunit is interpreted as shallow marine, deltaic, depositional system, occurred during sea level ¨normal¨ regression. This time, maximum flooding surface is located between the LLS and ULS. The lower Sarir subunit is terminated by subaerial unconformity, with evidences of subaerial exposure preserved at the top of the ULS. These are intruded by the upper Sarir subunit which presents clear evidences of strictly fluvial environment of deposition. The deposits of the upper Sarir subunit record the low stand system tract part of the Dur At Talah sequence. In addition to the outlined results, the sequential pattern of the depositional events is suggested for the entire sequence of Dur At Talah. This study provides a valuable information regarding the depositional and sequential aspects of the Sirt Basin during the late Eocene, it also provide an unique case study for the better understanding of the shallow marine tidal deposits.