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Quimioestratigrafia dos carbonatos da Formação Irati no leste do estado de São Paulo, Bacia do Paraná
| Content Provider | Semantic Scholar |
|---|---|
| Author | Kunrath, Rafaela Ferreira |
| Copyright Year | 2016 |
| Abstract | The Irati Formation (Lower Permian) is characterized by the rhythmicity of layers with extensive lateral lithological continuity, alternating between dolomitic limestones and shales rich in organic matter, as well as presenting several intrusions referring to Serra Geral magmatism, appearing as a potential hydrocarbon source for the The Paraná Basin. This unit is subject of several debates regarding its depositional environment, due to its singular characteristics that can cause ambiguity in the interpretations when indicating from lacustrine environments to epicontinental sea environments, or still transitional, where there is restriction in the water circulation . Considering the recurrent need for an understanding of potentially hydrocarbongenerating systems, it is proposed that the determination of stable isotopic ratios of carbon and oxygen in carbonates, as well as inorganic geochemistry, add an interesting tool for stratigraphy on the comprehension of depositional paleoenvironments and paleoclimates in the Irati Formation. As a work area, three quarries were chosen in the State of São Paulo: Bonança and Calcário Cruzeiro (without visible intrusions) and Partecal (with the occurrence of sills). It was possible to develop a metamorphic zoning in petrographic analisys, defining talc, serpentine and pyroxene zones, related to the hydrothermal effects of the contact metamorphism generated by the intrusions. Stable carbon and oxygen isotope analyzes showed values between -13.22 and + 1.18 ‰ (VPDB) at δ13C and values between -18.45 and -8.82 ‰ (VPDB) at δ18O for the Partecal quarry. For Bonança and Calcário Cruzeiro, the values of δ13C vary between -0.74 and +14.98 ‰ (VPDB), whereas those of δ18O vary between -7.79 and 6.65 ‰ (VPDB). The correlation between them makes it possible to see a negative shift of both signatures in the Partecal quarry, possibly due to contact with the igneous bodies. We analyzed the geochemical parameters of the Mn/Sr and Fe/Sr ratios, where it is suggested that the values of δ13C and δ18O of the samples in the Bonança and Calcário Cruzeiro quarries (with the exception of two anomalous samples) can be considered close to their primary signatures . |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.lume.ufrgs.br/bitstream/handle/10183/150926/001009866.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
