Thesis (Ph.D.) - Simon Fraser University, 2006. / Theses (Dept. of Archaeology) / Simon Fraser University. Includes bibliographical references (leaves 236-263). Also issued in digital format and available on the World Wide Web.

La « Formation Cangalli » (Cordillère Orientale, Bolivie) est une formation détritique, glaciofluviatile au potentiel aurifère (paléo-placer) avéré dans la région de Tipuani-Mapiri. Cette thèse a pour objectif de déterminer l’origine, la source, les modalités d’apport ainsi que les conditions de dépôts de la « Formation Cangalli » sur un secteur en cours d’évaluation par la société Rexma SAS (secteur de la mine « La Esperanza », sud de Caranavi). L’analyse de la structure de la formation et de la répartition de l’or doit permettre d’évaluer le potentiel aurifère de ce secteur et de proposer des guides de prospection de l’or. Le travail a consisté à développer en parallèle des approches terrain (topographie, cartographie, exploration de ruisseaux, étude de faciès sédimentologiques, études granulométriques sur gros volume, échantillonnage) et laboratoire (caractérisation des clastes et de la matrice par pétrographie optique, MEB, DRX, microsonde, CHONS). L’analyse sédimentologique a permis de proposer un modèle de remplissage en adéquation avec l’évolution tectonique de la Cordillère Orientale des Andes. Le remplissage présente 4 séquences dont 3 d’entre elles possèdent une alternance entre des dépôts fluviatiles et des dépôts de cônes alluviaux.La comparaison des deux faciès de Cangalli aisément identifiables sur le terrain par deux couleurs différentes (bleu et rouge) a montré que la distinction n’était pas stratigraphique mais liée à une altération affectant la formation initiale bleue.L’étude de la distribution des particules d’or (125-1000 μm) a montré que l’or est d’origine hydrothermale. De plus, les résultats montrent clairement que la distribution de l’or est hétérogène dans la « Formation Cangalli » les niveaux les plus enrichis se trouvant en base de séquence. Ces résultats permettent de poser les bases d’une exploitation industrielle de la concession minière. / The “Cangalli Formation” (Eastern Cordillera, Bolivia) is a detrital, glacofluvial formation with an established gold potential (paleo-placer) in the Tipuani-Mapiri region. This thesis aims to determine the origin, source, contribution and deposition conditions of the "Cangalli Formation" on an area being assessed by the Rexma SAS Company (area of the mine “La Esperanza”, south of Caranavi). The analysis of the formation structure and gold distribution should allow to evaluate the gold potential of this sector and to provide guidelines for gold prospecting. Two parallel approaches have been developed: fieldwork (topography, mapping, stream exploration, sedimentological study of facies, granulometry, sampling) and laboratory experiments (clasts and matrix characterization using optical petrography, SEM, XRD, microprobe, CHONS). Sedimentological analysis allowed to propose a filling model in line with the tectonic evolution of the Andean Cordillera Real. The filling shows 4 sequences, 3 of them consist of an alternation between fluvial and alluvial deposits. Comparison of the two Cangalli facies easily recognizable on the field by two different colors (blue and red) showed that the distinction was not stratigraphic but associated with an alteration affecting the initial blue formation. The study of the distribution of gold particles (125-1000 microns) showed that gold is of hydrothermal origin. In addition, the results clearly show that the gold distribution is heterogeneous in the "Cangalli Formation" the riches levels being in the basal sequences. These results lay the groundwork for industrial exploitation of the mining concession.

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xii, 165 p.; also includes graphics Includes bibliographical references (p. 135-148). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--Ohio State University, 1986. / Includes vita. Includes bibliographical references (leaves 383-416). Available online via OhioLINK's ETD Center.

Las estimaciones paleoclimáticas que utilizan rasgos asociados a hojas se basan en la estrecha relación moderna entre fisionomía foliar y clima, lo cual se denomina análogo moderno. Algunas de estas relaciones establecen que hojas grandes y sin dientes están asociadas a climas tropicales (caluroso y lluvioso), mientras que hojas pequeñas y dentadas se relacionan con climas templados. Sin embargo, estas relaciones modernas usan hojas de especies representativas de localidades boscosas y sin daño en su lámina, mientras que el conjunto de hojas presentes en una cuenca de depositación fósil representa un subset del ensamble original que, además, han pasado por un proceso tafonómico que puede variar la relación fisionomía-clima. Estudios previos han demostrado que los sesgos sí generan diferencias importantes, pero en climas fríos los sesgos disminuyen y estimaciones climáticas se acercarían a valores reales. Con el objetivo de evaluar posibles diferencias significativas en la fisonomía foliar entre herbario y hojarasca, y establecer posibles sesgos que ayuden a desarrollar análogos modernos más precisos, se estudiaron ambos grupos presentes en la localidad de Caunahué. Debido al carácter frío del clima de esta zona se espera que no existan diferencias fisonómicas. Para esto se analizaron 21 rasgos del análisis foliar digital para hojas de herbario y hojarasca de la vegetación que rodea el Río Caunahué, XIV región de Chile. Sin embargo, los resultados indican que en general sí existen diferencias entre hojas de herbario y de hojarasca, siendo esta última mucho más variable, por ende, no es conveniente su utilización en análogos modernos. / Palaeoclimatic estimates using traits associated to leaves are based in the narrow modern relationship between foliar physiognomy and climate, which is called modern analogue. Some of these relations establish that big untoothed leaves are related to tropical climates (thus, warm and rainy), while small toothed leaves are associated to template climates. However, these modern relationships use leaves from representative species of wooded locations and without any harm on its sheets, while the set of leaves in a fossil depositional basin represents a subset of the original assembly that, furthermore, these same leaves have gone through a taphonomic process that may vary the physiognomy-climate relation. Previous studies have demonstrated that biases do generate important differences, but in cold climates biases diminish and climatic estimates would approach real values. With the objective of testing possible significant differences in the physiognomy between herbarium leaves and litterfall, and establish possible bias to develop modern analogues conferring more accurate results, we studied both groups present in Caunahué. Because of the cold weather of this locality, it is expected that there will be no differences in physiognomy between herborized leaves and litter leaves. To do so, we analyzed 21 characters from digital foliar analysis of herborized leaves and litter leaves present in the vegetation surrounding Río Caunahué, XIV region of Chile. Nevertheless, results show that in general there are differences between herbarium leaves and litterfall leaves, the latter being much more variable, thus it is not convenient to use this in modern analogues.

The Lower Devonian (Deerparkian) Oriskany Group in eastern Pennsylvania has been shown to have been deposited under conditions of marine regression (Epstein etal, 1967). This study integrates field evidence and cumulative size ­frequency dat a in an investigation of the stratigraphic expression of marine regression. Lower Devonian paleogeo­graphy is interpreted, and the central Appalachian Basin shore line is adjusted from recently published maps (Boucot, 1968; Head, 1969) to include a land ·mass near Andreas, Pa. The Oriskany Group in eastern Pennsylvania is divided into three lithologic units based on bedding sequence, sed­imentary textures, and sedimentary structures. Lithologic unit one is a sequence of poorly bedded silty shales and siliceous argillaceous limestones which thickens to the northeast. The unit is interpreted as occupying an environmental position offshore and below wave base. Lithologic unit two is a sequence of thinly bedded coarse sandstones disconformably overlying, and interbedded with, rocks identical to those in unit one. Unit two represents depo­sition of sand by ripple trains or sand waves during storms in near (but below) -wave base environments of unit one. Lithologic unit three is a sequence of thick bedded sandstones which were deposited in a nearshore bar and beach environment. Analysis of cumulative size-frequency data supports the contention of Spencer (1963), that all sediments are mixtures of two or three log-normally distributed populations of sediment, and that sorting can only be defined by the degree of truncation of the size-frequency curve. Although the Oriskany is usually called a well sorted sand, only sand beds from Kunkletown (interpreted as the most nearshore of the three sections studied) show any evidence of sorting based on the above definition. Sand beds become coarser in a nearshore direction, but wide vertical fluctuations in coarseness measures· are present in any one section. The sequence of lithologies, textures, and structures of the Oriskany Group of eastern Pennsylvania are suggested as a model of the condition of marine regression. / Earth and Environmental Science

The distribution of gypidulid brachiopods in Siluro­-Devonian carbonates of the Appalachian basin is strictly limited by gypidulid specializations for poorly sorted sand substrates, normal salinity and good circulation. Gypidulid occurrences are limited to open shelf near wave base sands which are closely associated with trans­gressive barrier systems. Regressive phases of carbonate deposition lack suitable substrates for gypidulid habita­tion. Progressive adaptive morphologic change in gypidulid spondylium/beak shape parallels progressive decrease in restriction of the gypidulid environment. Canonical analy­sis and comparisons of mean shape ratios, reduced major axes and allometric curves are used to statistically define variation in spondylium shape and size in three successive populations of gypidulius. Statistical tests indicate significant differences in spondylium/beak shape and size between species. Persistence of significant change in growth (allometric) curves through time indicates genetic change in successive populations. / Earth and Environmental Science

Thesis (Ph.D.)--McMaster University, 2003. / Advisor: A. Cannon. Includes bibliographical references (p. 324-353). Also available via World Wide Web.

Here I develop a cross-correlation approach to estimating heights of shoreline features, and apply the new method to paleo-shorelines of Pleistocene Lake Bonneville. I calculate 1st-derivative (slope) and 2nd-derivative (curvature) profiles from Digital Elevation Model (DEM) or Global Positioning System Real-Time Kinematic (GPS-RTK) measurements of elevation. I then cross-correlate pairs of profiles that have been shifted by various "lags," or shifts in elevation. The correlation coefficient (a normalized dot-product measure of similarity) is calculated as a function of lag within small (~40 m) windows centered at various elevations. The elevation and lag with the greatest correlation coefficient indicates the shoreline elevation at the reference profile and the change in shoreline height for the profile pair. I evaluate several different algorithms for deriving slope and curvature by examining closure of elevation lags across profile triples. I then model isostatic response to Lake Bonneville loading and unloading. I first model lakeshore uplift response to lake load removal assuming an elastic layer over an inviscid half-space. I obtain a best-fit comparison of predicted to observed shoreline heights for the Bonneville level with an elastic layer thickness, Te, of 25±2 km (at 95% confidence) when using only previously published shoreline elevation estimates. The best-fit for the Bonneville level when using these estimates plus 44 new estimates suggests a Te of 26±2 km. The best-fit model for the Provo level suggests Te of 17±3 km. For the Gilbert level, the response is insensitive to the assumed Te. I next model isostatic response to Bonneville loading and unloading assuming an elastic layer over a viscoelastic halfspace. This approach assumes constant parameters for the entire loading history, and yields a best-fit model with Te =70±5 km and viscosity ç=~2x1018 Pa s with 95% confidence ranging from ~1x1018 to ~5x1019 Pa s when only the previously published data are used. With the newer data added, the best-fit model has Te =58±2 km and ç ranging from ~1x1018 to ~1x1019 Pa s with 95% confidence. The 12-15 m weighted root-mean-square misfit to the best-fitting model is dominated by tectonic signals related to Basin-and-Range tectonics particularly seismic offsets of the Wasatch fault, and closely mimics the geological timescale pattern of basin-subsidence and range-uplift.

Thesis (M.A.)--Memorial University of Newfoundland, 2003. / Bibliography: leaves 179-193.