Contribuição à análise de proveniência sedimentar pelo método Traços de Fissão em zircão e influências estruturais para a formação do Planalto Residual de Marília

• Autor(a) principal: Santos, Caio Augusto Marques dos [UNESP]
• Data de Publicação: 2014
• Outros Autores: Nunes, João Osvaldo Rodrigues [UNESP], Sáenz, Carlos Alberto Tello [UNESP]
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.20502/rbg.v14i3.440; http://hdl.handle.net/11449/135407
• topic: Marília residual plateau; Fissiontrack; Structures; Planalto residual de Marília; Traço de fissão; Estruturas

Marília Residual Plateau is constituted as a typical board shaped relief of sedimentary basin center. Its formation generated a big summit compartment interconnected to secondary summits of minor extension. The domain of the hillsides fi nishes at abrupt slopes with 50 to 100 meters invernesses which delimitate and surround the plateau. Due to its singular relief forms it was aimed to understand its genesis and evolution, since its sedimentary source up to the constitution as residual plateau. In order to reach this aim it was used dating through fi ssion track method in 68 Zircon grains collected from rocks of Marília Formation in the city of Marília – SP, and through the use of bibliographical review understand the structural infl uences on the genesis of Marília Residual Plateau. The ages, which varied from 640 to 80 million years, suggest different thermotectonic events in different areas of rock-source supplier of detritic material. Concerning to the structural infl uences, they are connected to the weak zones of Paraná Basin basement. The diverse geological formations superimposed inherited these characteristics of the crystalline basement through structural alignments. The post cretaceous epeirogenesis accelerated the rivers which fl owed to west towards Paraná River and this provided the beginning of the plateau isolation in the landscapes of west of São Paulo state. In the gondwanic separation context, the tensions which came from tectonic efforts generated breakable deformation in the rocks of Marília Formation, levels of local basis where started the hydrographic system organization and the plateau sculpture.