Thesis (Ph. D.)--University of Wisconsin--Madison, 1952. / Typescript. Two folded charts in pocket. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 83-87).

Thesis (M.S.)--Baylor University, 2005. / Includes bibliographical references (p. 142-147).

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 91-96)

Thesis (M.S.)--Rutgers University, 2010. / "Graduate Program in Geological Sciences." Includes bibliographical references (p. 32-36).

Thesis (M.S.)--Brigham Young University. Dept. of Geology, 2004. / Includes bibliographical references (leaves 187-189).

Thesis (M.Sc.)--Memorial University of Newfoundland, 2003. / Bibliography: leaves 132-143. Also available online.

M.Sc. / Please refer to full text to view abstract

A quantitative forward model has been developed to investigate the controls on the deposition, erosion, and preservation of passive rift margin stratigraphy. The model includes thermal subsidence, variable absolute sealevel, flexural isostasy, subaerial and submarine deposition on fluvial and marine equilibrium profiles, and the facility to vary sediment supply through time. Results from the quantitative model can be used to reproduce elements of the sequence stratigraphic depositional model. Conducting sensitivity tests demonstrates that variables such as sediment supply and fluvial profile behaviour are likely to be of equal importance to thermal subsidence and eustasy in passive margin stratigraphy. Sensitivity tests with the quantitative model also demonstrate the problems associated with attempting to use a discretised stratigraphic model to investigate unforced cyclicty resulting from complex interactions in stratigraphic systems. Although the model appears capable of producing such unforced cyclical behaviour, this cyclicity is shown to be due to a numerical instability within the model which occurs with certain initial conditions and assumptions. The applicability of the model to observed stratigraphy is tested by comparing specific model output to patterns of stratigraphy from the North American Atlantic margin. The results from this test demonstrate that although the model is in many respects simplistic when compared to the complexities of natural systems, it is nevertheless capable of reproducing some of the basic elements of the observed stratigraphic patterns.

Thèse (D.R.Min.) -- Université du Québec à Chicoutimi, programme extensionné à l'Université du Québec à Montréal, 2003. / Bibliogr.: f. 203-204. Document électronique également accessible en format PDF. CaQCU

Orientador: Fresia Soledad Ricardi Tores Branco / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-22T19:10:06Z (GMT). No. of bitstreams: 1 Fanton_JeanCarloMari_D.pdf: 19867542 bytes, checksum: 5b38f9327cfcd9fa334e56499a15d4bc (MD5) Previous issue date: 2013 / Resumo: Folhas isoladas de angiospermas preservadas em depósitos fluvio-lacustres das bacias de Fonseca e Gandarela foram analisadas visando reconstruir o paleoambiente. Angiospermas são bons indicadores climáticos, pois a distribuição de suas espécies no espaço/tempo e influenciada pelo clima. Localizadas no centro-sul de Minas Gerais, as bacias de Fonseca e Gandarela são grabens encravados no embasamento Pré-Cambriano, depositados nos intervalos Neoeoceno-Eoligoceno e Neoeoceno- Eomioceno (respectivamente), segundo dados paleológicos. Como métodos, alem da morfotipificação, características arquiteturais informativas permitiram identificações taxonômicas com base apenas em folhas. Para estimar as paleotemperaturas, aplicou-se a Analise da Margem Foliar (LMA) utilizando a relação entre a proporção de espécies arbóreas "dicotiledôneas" com margens lisas (pE) e a media anual de temperatura (MAT). Antes, a habilidade de modelos sul-americanos foi testada em florestas atlânticas do sudeste. Devido à pEs altas (0,78-0,87), as temperaturas dos locais quentes-baixos (MAT ? 23°C) foram estimadas corretamente, mas o erro foi maior nos locais frios-elevados (MAT ? 22°C, 610-890 m). Mesmo que linhagens obrigatoriamente lisas estiveram super-representadas tanto nos locais quentes quanto frios (em media 38% das espécies/local), o desenvolvimento de terras altas desde o Neocretaceo e Cenozóico no sudeste inviabiliza hipóteses de tempo insuficiente para a evolução de margens denteadas nas angiospermas adaptadas a altitude. Para Fonseca (40 morfotipos) e Gandarela (20) foram obtidas pEs tão altas (0,90 e 0,95) quanto às de florestas equatoriais amazônicas atuais. MATs ? 24,7°C foram reconstruídas pela maioria dos modelos (em media ?27-28°C), faixa megatermica hoje registrada principalmente em terras-baixas do norte e nordeste do Brasil. Mais da metade dos 25 morfotipos aqui descritos foram identificados em famílias tropicais, como Lauraceae (FS06, GR03 e GR09), Fabaceae (FS01-03, FS05, FS09 e GR08), Combretaceae (FS08) e Myrtaceae (FS11-13 e GR02). Todas são linhagens com uma longa historia evolutiva (no mínimo desde o Paleoceno-Eoceno) no norte (Fabaceae e Lauraceae) e no sul (Myrtaceae) da America do Sul, expondo um antigo legado de tropical idade e influencia floristica mista (boreal-laurasiana e austral-antartica). Hoje no sudeste, tais famílias controlam boa parte dos recursos ecológicos na Mata Atlântica e provavelmente já o faziam nas florestas do Neopaleogeno. Devido à composição e certas condições ambientais compartilhadas, as florestas ombrofilas do compartimento sul da Mata Atlântica (inclusive a Floresta Ombrofila Mista, FOM) são analogias modernas parcialmente comparáveis com Fonseca e Gandarela: temperaturas e pluviosidade elevadas mantendo um dossel sempre-verde e multiestratificado, dominado por angiospermas (Myrtaceae, Lauraceae e Fabaceae) e coníferas austrais (Podocarpaceae e Araucariaceae). Confirmam a reconstrução de florestas tropicais úmidas: (1) o conjunto fisionômico da Formação Fonseca (onde 40- 65% dos morfotipos avaliados têm ápice acuminado, 80-90% margens lisas e 50% notofilo-mesofilos) e (2) a presença de linhagens que demandam umidade e intolerantes ao frio, como podocarpaceas dacrydioides (Dacrydiumites) e mirtaceas como FS13 (identificado em Curitiba), exibindo uma folha acuminada 2× maior que da atual C. prismática, espécie endêmica da FOM. O cenário reconstruído se ajusta aos níveis superiores de CO2 atmosférico, maior zona tropical e invernos relativamente brandos do final do Paleogeno / Abstract: Isolated fossil angiosperm leaves preserved in fluvial-lacustrine deposits from the Fonseca and Gandarela basins were analyzed to reconstruct the paleoenvironment. Angiosperms are good climatic indicators since the species distribution in space/time is influenced by the climate. Located in central-southern part of the State of Minas Gerais, the Fonseca and Gandarela basins are grabens embedded in the Precambrian basement, deposited during the Late Eocene-Early Oligocene interval, according to palynological data. As methods, informative architecture characteristics allowed taxonomic identifications solely on the basis of leaves. To estimate paleotemperatures, the Leaf Margin Analysis (LMA) was applied, based on the relationship between the proportion of untoothed woody "dicot" species (pE) and mean annual temperature (MAT). Before, the ability of South American models was tested on modern sites of Atlantic forests from southeastern Brazil. Because of high pEs (0,78-0,87), temperatures of the low-elevation sites (MAT ? 23°C) were predicted accurately, but the error was greater in the high-elevation ones (MAT ? 22°C, 610-890 m). Although obligate untoothed lineages were richly represented in low and high-temperature sites (in average 38% of the species per site), the development of highlands in southeastern Brazil since the Late Cretaceous and Cenozoic invalidate hypotheses about an insufficient time to evolve teeth in angiosperms adapted to high-elevations. Both fossil floras Fonseca (40 morphotypes) and Gandarela (20) showed pEs (0,90 and 0,95) so high as observed in Amazonian equatorial rainforests. MATs ? 24,7°C were yielded for the majority of the models (in average ?27-28°C), isotherm today registered mainly in lowlands from northern Brazil. Over half of the morphotypes described were identified in families essentially tropical, such as Lauraceae (FS06, GR03 and GR09), Fabaceae (FS01-03, FS05, FS09 and GR08), Combretaceae (FS08) and Myrtaceae (FS11-13 and GR02). All these lineages have a long evolutionary history (since at least the Paleocene- Eocene) in the north (Fabaceae and Lauraceae) and south (Myrtaceae) of South America, revealing an antique legacy of tropicality and mixed floristic influence from boreal-laurasian and austral-Antarctic regions. Today, such families have controlled a major portion of the ecological resources in the Atlantic forests from southeastern Brazil probably retaining dominance since the Paleogene. Similar composition and some environmental aspects suggest that the rainforests from the southern Atlantic block (including Araucaria rainforest) are the closest living analogues to the Fonseca and Gandarela extinct vegetation: high temperatures and heavy rainfall sustaining an evergreen and multilayered canopy dominated by angiosperms (Myrtaceae, Lauraceae and Fabaceae) and austral conifers (Podocarpaceae and Araucariaceae). Additional evidence supporting the tropical rainforest hypothesis is: (1) the Fonseca Formation leaf physiognomy (40-65% of the morphotypes evaluated have drip tips, 80-90% untoothed margins and 50% are notophyll-mesophyll), and (2) the presence of water-demanding and coldintolerant lineages, such as dacrydioid podocarps (Dacrydiumites) and the Myrtaceae morphotype FS13 (identified as Curitiba), which bears an acuminate leaf 2× longer than the extant C. prismatica. The paleoenvironment reconstructed agree with the higher atmospheric CO2 levels, the wider Tropical zone and the relatively mild winters during the Late Paleogene / Doutorado / Geologia e Recursos Naturais / Doutor em Ciências