Estudo sedimentológico e petrográfico dos carbonatos continentais da Bacia de Itaboraí

• Autor(a) principal: Pereira, Gustavo do Couto Ramos
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/7129
• topic: Continental Carbonate; Travertine; Itaborai Basin; Sinter; Abiotic; Carbonato Continental; Travertino; Bacia de Itaboraí; Sinter; Abiótico; CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::SEDIMENTOLOGIA

The travertine located in the Itaborai Basin in the state of Rio de Janeiro, designated Itaborai Formation and dated back Paleocene for their content in fossil vertebrates are deposited in small half graben basin, despite the small size of the basin (1,5Kmx0,5Km) it represents a huge source of information including a diverse preserved biota, presence of sinter along travertine precipitation, exposition of alcaline dyke and the possibility of analog model for pre-salt reservoir. Most of the studies regarding the basin are related to the extensive fossil community from the lake-fill facies association; facies not directly related to the thermal precipitation.The banded travertine and facies associated lacks of studies envolving petrography and facies association. The Research presented intend to recognize the remarking structures and textures in thin sections, describe the facies, identify the sinter-travertine relationship as well, in order to establish a facies association and the geologic interpretation assisted with isotope δ13C/δ18O analysis. To achieve this goal, mapping, sedimentologic, petrographic and isotopic studies were carried out. As Results, two depositional settings were recognized; travertine deposited along the active fault border and the travertine deposited in the less tectonic affected portion of the basin. For these two settings was established a profile with their deposits characteristics and its deposional processes. The conclusion obtained were the macro- and microscopic features observed indicated a presence of major abiotic influence during the process of thermal precipitation, controlled mainly by tectonic activity pulses of the distentional hemi-graben system, while the stable isotope ratios provided contrasting data to the characteristic thermogene travertine signature, raising discussion of mixed processes afecting the isotopes and the possible influence of magmatic events, diagenesis and climate events in Isotopic fractionation