Interpretações paleoambientais com base em padrões anatômicos de lenhos fósseis
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2019-01
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Jasper, André
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Nas Ciências Ambientais, a construção do conhecimento ambiental deve integrar diferentes áreas, entre elas a adequada compreensão das características dos ecossistemas pretéritos. Estudos que analisem as características básicas da evolução do Sistema Terra ao longo do tempo, contribuem de forma significativa para entendimento das dinâmicas atuais. Tendo em vista que as plantas são excelentes marcadores ecológicos, a paleobotânica tem muito a contribuir nesse sentido, e os dados produzidos são fundamentais para um enfoque conceitual ampliado da área. Dentre as diferentes avaliações possíveis, o estudo das características de lenhos, constitui-se em excelente ferramenta para a inferência de variáveis paleoambientais
predominantes quando do crescimento da planta. Neste contexto, o presente estudo investigou as características anatômicas de lenhos preservados por permineralização ou carbonização provenientes do Permiano das bacias do Parnaíba e do Paraná, além de um lenho permineralizado do Plioceno-Pleistoceno do Rio Grande do Sul com a finalidade de construir inferências paleoambientais para os sistemas deposicionais em que se formaram. O material proveniente da Formação Touro Passo, foi associado a Subfamília Mimosoideae (Fabaceae), e nomeado como Itaquixylon heterogenum. Já o material proveniente do Permiano da Bacia do Paranaíba, tem afinidades gimnospérmicas, e permitiu confirmar a predominância de um clima semi-árido para a área de estudo. Por fim, o material proveniente do Permiano da Bacia do Paraná, se
constituem de fragmentos de macro-charcoal investigados para o afloramento Porongos, e fornecem a primeira evidência da ocorrência de recorrentes paleoincêndios vegetacionais durante os depósitos da camada de carvão Barro Branco. Já os fragmentos carbonizados coletados no afloramento Barrocada,
fornecem a primeira evidência de paleoincêndios vegetacionais para o Grupo Itararé. A integração dos dados advindos das diferentes áreas e idades, permitiu estabelecer que o estudo da anatomia de lenhos fósseis, independente da sua forma de preservação, é uma ferramenta imprescindível para a definição das características dos sistemas em que foram depositados e, portanto, sempre que possível devem ser
considerados em estudos voltados à compreensão da evolução do Sistema Terra ao longo do tempo. Além disso, independentemente da idade e origem dos registros, reforça-se a necessidade de utilização de dados advindos da paleobotânica para a compreensão dos processos envolvidos nas dinâmicas dos ambientes atuais.
In Environmental Sciences, the construction of environmental knowledge must integrate different areas, among them the proper understanding of the characteristics of the past ecosystems. Studies that analyze the basic characteristics of the evolution of the Earth System over time, contribute significantly to understanding the current dynamics. Considering that plants are excellent ecological markers, paleobotany has much to contribute in this sense, and the data produced are fundamental to an extended conceptual approach of the area. Among the different possible evaluations, the study of wood characteristics is an excellent tool for the inference of paleoenvironmental variables predominant when plant growth occurs. In this context, the present study investigated the anatomical characteristics of woodlands preserved by permineralization or carbonization from Permian of the Parnaíba and Paraná basins, as well as a permineralized wood from Pliocene-Pleistocene Rio Grande do Sul in order to construct paleoenvironmental inferences for the depositional systems in which they were formed. The material coming from the Touro Passo Formation, was associated to the Subfamily Mimosoideae (Fabaceae), and named as Itaquixylon heterogenum. On the other hand, the material from Permian of the Paranaíba Basin has gymnospermic affinities, and confirmed the predominance of a semi-arid climate for the study area. Finally, the material coming from the Permian of the Paraná Basin, consisted of macro-charcoal fragments investigated for the Porongos outcrop, and provide the first evidence of the occurrence of recurrent vegetation paleoincences during the deposits of the Barro Branco coal layer. The carbonized fragments collected in the Barrocada outcrop provide the first evidence of vegetative paleoincences for the Itararé Group. The integration of data from different areas and ages allowed us to establish that the study of the anatomy of fossil wood, regardless of its form of preservation, is an essential tool for defining the characteristics of the systems in which they were deposited and, therefore, whenever should be considered in studies aimed at understanding the evolution of the Earth System over time. In addition, regardless of the age and origin of the records, the need to use data from paleobotany to understand the processes involved in the dynamics of current environments is reinforced.
In Environmental Sciences, the construction of environmental knowledge must integrate different areas, among them the proper understanding of the characteristics of the past ecosystems. Studies that analyze the basic characteristics of the evolution of the Earth System over time, contribute significantly to understanding the current dynamics. Considering that plants are excellent ecological markers, paleobotany has much to contribute in this sense, and the data produced are fundamental to an extended conceptual approach of the area. Among the different possible evaluations, the study of wood characteristics is an excellent tool for the inference of paleoenvironmental variables predominant when plant growth occurs. In this context, the present study investigated the anatomical characteristics of woodlands preserved by permineralization or carbonization from Permian of the Parnaíba and Paraná basins, as well as a permineralized wood from Pliocene-Pleistocene Rio Grande do Sul in order to construct paleoenvironmental inferences for the depositional systems in which they were formed. The material coming from the Touro Passo Formation, was associated to the Subfamily Mimosoideae (Fabaceae), and named as Itaquixylon heterogenum. On the other hand, the material from Permian of the Paranaíba Basin has gymnospermic affinities, and confirmed the predominance of a semi-arid climate for the study area. Finally, the material coming from the Permian of the Paraná Basin, consisted of macro-charcoal fragments investigated for the Porongos outcrop, and provide the first evidence of the occurrence of recurrent vegetation paleoincences during the deposits of the Barro Branco coal layer. The carbonized fragments collected in the Barrocada outcrop provide the first evidence of vegetative paleoincences for the Itararé Group. The integration of data from different areas and ages allowed us to establish that the study of the anatomy of fossil wood, regardless of its form of preservation, is an essential tool for defining the characteristics of the systems in which they were deposited and, therefore, whenever should be considered in studies aimed at understanding the evolution of the Earth System over time. In addition, regardless of the age and origin of the records, the need to use data from paleobotany to understand the processes involved in the dynamics of current environments is reinforced.
Descrição
Palavras-chave
Charcoal; Lenhos permineralizados; Evolução de biomas; Paleobotânica; Paleoambiente; Paleoecologia; Gondwana; Evolution of biomes; Environmental dynamics; Paraná Basin; Parnaíba Basin; Gondwana
Citação
BENÍCIO, José Rafael Wanderley. Interpretações paleoambientais com base em padrões anatômicos de lenhos fósseis. 2019. Tese (Doutorado) – Curso de Ambiente e Desenvolvimento, Universidade do Vale do Taquari - Univates, Lajeado, 28 fev. 2019. Disponível em: http://hdl.handle.net/10737/2515.