DEGEO - Departamento de Geologia
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/8
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Resultados da Pesquisa
Item Benchmarking analogue models of brittle thrust wedges.(2016) Schreurs, Guido; Buiter, Susanne J. H.; Boutelier, Jennifer; Burberry, Caroline; Callot, Jean Paul; Cavozzi, Cristian; Cerca, Mariano; Chen, Jian Hong; Cristallini, Ernesto; Cruden, Alexander R.; Cruz, Leonardo; Daniel, Jean Marc; Poian, Gabriela Da; Garcia, Victor H.; Gomes, Caroline Janette Souza; Grall, Céline; Guillot, Yannick; Guzman, Cecilia; Hidayah, Triyani Nur; Hilley, George; Klinkmüller, Matthias; Koyi, Hemin A.; Lu, Chia Yu; Maillot, Bertrand; Meriaux, Catherine; Nilfouroushan, Faramarz; Pan, Chang Chih; Pillot, Daniel; Portillo, Rodrigo; Rosenau, Matthias; Schellart, Wouter P.; Schlische, Roy W.; Take, Andy; Vendeville, Bruno; Vergnaud, Marine; Vettori, Matteo; Wang, Shih Hsien; Withjack, Martha O.; Yagupsky, Daniel; Yamada, YasuhiroWe performed a quantitative comparison of brittle thrust wedge experiments to evaluate the variability among analogue models and to appraise the reproducibility and limits of model interpretation. Fifteen analogue modeling laboratories participated in this benchmark initiative. Each laboratory received a shipment of the same type of quartz and corundum sand and all laboratories adhered to a stringent model building protocol and used the same type of foil to cover base and sidewalls of the sandbox. Sieve structure, sifting height, filling rate, and details on off-scraping of excess sand followed prescribed procedures. Our analogue benchmark shows that even for simple plane-strain experiments with prescribed stringent model construction techniques, quantitative model results show variability, most notably for surface slope, thrust spacing and number of forward and backthrusts. One of the sources of the variability in model results is related to slight variations in how sand is deposited in the sandbox. Small changes in sifting height, sifting rate, and scraping will result in slightly heterogeneous material bulk densities, which will affect the mechanical properties of the sand, and will result in lateral and vertical differences in peak and boundary friction angles, as well as cohesion values once the model is constructed. Initial variations in basal friction are inferred to play the most important role in causing model variability. Our comparison shows that the human factor plays a decisive role, and even when one modeler repeats the same experiment, quantitative model results still show variability. Our observations highlight the limits of up-scaling quantitative analogue model results to nature or for making comparisons with numerical models. The frictional behavior of sand is highly sensitive to small variations in material state or experimental set-up, and hence, it will remain difficult to scale quantitative results such as number of thrusts, thrust spacing, and pop-up width from model to nature.Item Testing the influence of a sand mica mixture on basin fill in extension and inversion experiments.(2014) Gomes, Caroline Janette Souza; D'Angelo, Taynara; Almeida, Gisela Miranda de SouzaCompara-se a deformação produzida em areia e em uma mistura de areia com cristais de micas (na proporção 14:1, em peso), empregadas para simular o preenchimento de uma bacia em modelos de extensão e inversão, para analisar o potencial da mistura areia com cristais de micas para o uso em modelos físicos que requerem um material analógico, de fortes propriedades elasto-fricional plásticas. A areia e a mistura areia com cristais de micas possuem ângulos de atrito interno, similares, mas a mistura se deforma sob uma tensão cisalhante crítica significativamente mais baixa. Na extensão, os experimentos nos quais a mistura areia com cristais de micas preenche as bacias revelam um número menor de falhas normais. Durante a inversão, a diferença mais importante entre as bacias, preenchidas com areia e com a mistura areia com cristais de micas, é relacionada à deformação interna de dobras de propagação de falhas que cresce com o aumento do ângulo de atrito basal. Conclui-se que a mistura areia com cristais de micas, de fortes propriedades elastofricional plásticas, pode ser empregada para a simulação de dobras em experimentos que pretendem simular uma inversão moderada, na crosta rúptil.