A porção superior da Formação Corumbataí (Permiano, Bacia do Paraná) na região de Piracicaba (SP)

• Autor(a) principal: Lopes, Fernando Danubio Sousa [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/155464; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-06-05/000884220.pdf
• topic: Geologia estratigráfica - Permiano; Diques (Geologia); Petrologia; Piracicaba (SP); Paraná, Bacia

The present study describes and interprets the upper part of the Corumbataí Formation (Passa Dois Group, Paraná Basin, Permian, Kungurian-Roadian) and the basal part of the Piramboia Formation (São Bento Group, Jurassic?) in the northwest region of Piracicaba city (SP). A stretch of three kilometers of the highway SP-304, partially in duplication works, offered excellent expositions from the Condomínio Colinas de Piracicaba (UTM 7.491.618N/ 213.671E, datum Córrego Alegre) towards Águas de São Pedro. This study presents a detailed characterization of the sedimentary facies and of the boundary between the two formations; a preliminary identification of the main fossils; three columnar sections on a scale of 1:100, which were correlated for a composite columnar section of 48.5 m; collection, petrologic and petrographic analyses of samples and 16 thin sections; preliminary stratigraphic correlations with a previously described well between Botucatu and Anhembi; and the data interpretation focusing on the paleoenvironments, paleoclimates and cyclic successions. The predominant lithologies are heterolithic rocks (couplets of claystone/siltstone and very fine/fine sandstones) with flaser, wavy and lenticular bedding, frequently bioturbated and with mudcracks, organized in coarsening upwards cyclic successions, sometimes covered by fine sandstones with wave or hummocky cross stratification. Few calcilutite/biomicrite beds in a 1.5 m thick interval bear abundant fossils as ostracods, fish scales and teeth, coprolites, stem fragments and microphylls of lycophites and tiny pecopterids. The obtained data are coherent with previous interpretations for equivalent intervals of the Corumbataí Formation, i.e., the sedimentation probably occurred in an epeiric sea without evident communication with the open ocean, influenced by storm... (Complete abstract electronic access below)