The giant stromatolite field at Santa Rosa de Viterbo, Brazil (Parana Basin) - A new paleoenvironmental overview and the consequences of the Irati Sea closure in the Permian

Autor(es)

Callefo, F. ^[1] ; Arduin, D. H. ^[1] ; Ricardi-Branco, F. ^[1] ; Galante, D. ^[2] ; Rodrigues, F. ^[3] ; Branco, F. C. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Geociencias, P Box 6152, BR-13083855 Campinas, SP - Brazil

^[2] LNLS CNPEM, Brazilian Synchrotron Light Lab, BR-13083100 Campinas, SP - Brazil

^[3] Univ Sao Paulo, Dept Fundamental Chem, Inst Chem, BR-05508000 Sao Paulo - Brazil

^[4] EnvironMentality, BR-04566000 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of South American Earth Sciences; v. 84, p. 299-314, JUL 2018.
• Citações Web of Science: 1

Resumo

The city of Santa Rosa de Viterbo, Sao Paulo State, Brazil, contains an important geological and paleontological site that is part of the Parana Basin and presents one of the most significant records of Permian microbial life of southwestern Gondwana: the giant stromatolite field, with structures reaching 3 m high and 6 m wide. This work proposes a new overview of the paleoenvironment, focusing on the growth and development of microbial mats and microbialites. The characterization and association of nine facies were performed: intraformational breccia with wackestone matrix, intraformational breccia with grainstone matrix, packstone, wackestone, microbial mats, peloidal wackestone, laminated peloidal wackestone, laminated peloidal packstone and stromatolites. Four lithologic logs were correlated and used to interpret the history of the establishment of microbial communities during the episode of the Irati Sea closure. Field studies were carried out, thin sections were analyzed, and techniques such as SEM/EDS and Raman spectroscopy were applied for compositional analysis and to aid in the identification of associated fossils. This moment in the Parana Basin's evolution was important due to the noteworthy increase in rates of organic matter deposition and the significant proliferation of microbial life brought about by the closure of the Irati Sea. One hypothesis is that there was more than one attempt to establish microbial communities during the paleoenvironmental evolution, and success was achieved only after a decrease in water depth and energy of the depositional system, as well as after an increase in salinity. As a result of a reconfiguration of paleogeography in the Gondwana supercontinent, the closure of the Irati Sea significantly affected the development and establishment of microbial communities, which gave rise to extensive microbialitic structures such as those at Santa Rosa de Viterbo. (AU)

• Processo FAPESP: 13/11563-6 - Integração de dados multifonte para análise paleobotânica da Bacia do Paraná no intervalo Carbonífero-Permiano
• Beneficiário: Fresia Soledad Ricardi Torres Branco
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 16/20927-0 - Estudos de acumulações modernas e fósseis de bioclastos em ambientes continentais e costeiros.
• Beneficiário: Fresia Soledad Ricardi Torres Branco
• Modalidade de apoio: Auxílio à Pesquisa - Regular