Morro do Chaves Formation are considered important potential hydrocarbons source rock of
the Sergipe-Alagoas basin. Cretaceous shales from Morro do Chaves Formation have been investigated to identify their isotopic signature and source areas by stable sulphur ä34S
isotopes technique. In addition, this study shows the potential source rocks based on organic geochemical parameters. The 16 samples of shales were collected and submitted to total organic carbon (TOC), total sulphur (S), Rock-Eval pyrolysis and stable sulphur isotopes ä34S.
The TOC and Rock Eval results revealed high organic contents and the predominance of kerogen classified as type I. The results of the geochemical analyses indicated TOC and S contents reaching 9,22% and 1,67%, respectively and it was possible to observe two intervals anoxic events. The results indicate sea water source from the bacterial sulfate reduction to high values of the sulfur isotopic ratio and low values reflect the isotopic signature of meteoric water. The paleoenvironment conditions were characterized like lagoon ambient with possibility marine invasion. / O objetivo deste trabalho visa caracterizar a geoquimica de folhelhos do periodo Cretaceo da Formacao Morro do Chaves, Bacia Sergipe-Alagoas. Foram estudadas 16 amostras de
folhelhos submetidas a analise de carbono organico total (COT), enxofre Total (S), pirolise Rock Eval e razao isotopica de enxofre Â34S com o objetivo de identificar a assinatura
isotopica e possiveis areas fontes. Os resultados de COT e Rock Eval demonstrou alta quantidade de materia organica e determinou-se o querogenio caracteristico como do tipo I,
essencialmente algalica. Os resultados da analise geoquimica de COT e S atingiram valores de 9,22% e 1,67%, respectivamente, possibilitando a identificacao de dois intervalos anoxicos. Os resultados isotopicos identificaram duas provaveis fontes, sendo os altos valores relacionados a reducao bacteriana de sulfato provenientes de agua marinha, os baixos valores provenientes de fonte meteorica e os valores intermediarios de ambas as fontes. As condicoes paleoambientais foram caracterizadas como um ambiente lagunar que possivelmente ocorreu invasoes marinhas no sistema.
| Identifer | oai:union.ndltd.org:IBICT/oai:ri.ufs.br:riufs/5391 |
| Date | 26 March 2013 |
| Creators | Pontes, Naedja Vasconcelos |
| Contributors | Garcia, Antônio Jorge Vasconcellos |
| Publisher | Pós-Graduação em Geociências e Análise de Bacias |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFS, instname:Universidade Federal de Sergipe, instacron:UFS |
| Rights | info:eu-repo/semantics/openAccess |
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