Publicação
Environmental evolution of the Ria Formosa barrier islands system during the Pleistocene-Holocene based on very highresolution reflection seismic profiles
| Resumo: | This study analyses the seismic stratigraphy of the Algarve coast, in order to understand the evolution of the Ria Formosa Barrier Island System (RFBIS), once is not well established yet. This was based on seismic profiles from previous data collection. The RFBIS consists of five islands and two peninsulas, dynamically shaped by waves, tides, sea-level rise, and storms. These systems are vulnerable to threats like erosion and sea-level rise, making it crucial to understand their geological evolution in response to environmental changes. The study focuses on interpreting seismic discontinuities and sedimentary units, of the platform adjacent to the system, on its western side, to infer depositional environments, using previously analysed cores. Four seismic discontinuities (D1-D4) were identified, along with five main seismic units (U1-U5). The data indicates that the bottom of the unit U5, the upper most unit, is dating to 8280 ± 30 BP (Conventional Age). Because U5 is the youngest unit it is inferred that its deposition is synchronous to the formation of the barrier islands. The seismic and core data analysis, including sediment dating, provides insights into the dynamic interaction between sea-level changes, sediment deposition, and erosion. This study helps establish a geological timeline for the system, considering factors such as the complexity of the area in which it is located, and offers a framework for understanding the intricate processes beneath the evolution of the RFBIS over time. However, the system’s full development stages remain uncertain due to the area's complexity, but this study is a starting point to better understand the steps for the reconstruction of the system. |
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| Autores principais: | Amaral, Joana Tavares Perfeito |
| Assunto: | Ilhas-barreira Algarve análise sísmica cores sedimentares Relatórios de estágio de mestrado - 2024 |
| Ano: | 2024 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | This study analyses the seismic stratigraphy of the Algarve coast, in order to understand the evolution of the Ria Formosa Barrier Island System (RFBIS), once is not well established yet. This was based on seismic profiles from previous data collection. The RFBIS consists of five islands and two peninsulas, dynamically shaped by waves, tides, sea-level rise, and storms. These systems are vulnerable to threats like erosion and sea-level rise, making it crucial to understand their geological evolution in response to environmental changes. The study focuses on interpreting seismic discontinuities and sedimentary units, of the platform adjacent to the system, on its western side, to infer depositional environments, using previously analysed cores. Four seismic discontinuities (D1-D4) were identified, along with five main seismic units (U1-U5). The data indicates that the bottom of the unit U5, the upper most unit, is dating to 8280 ± 30 BP (Conventional Age). Because U5 is the youngest unit it is inferred that its deposition is synchronous to the formation of the barrier islands. The seismic and core data analysis, including sediment dating, provides insights into the dynamic interaction between sea-level changes, sediment deposition, and erosion. This study helps establish a geological timeline for the system, considering factors such as the complexity of the area in which it is located, and offers a framework for understanding the intricate processes beneath the evolution of the RFBIS over time. However, the system’s full development stages remain uncertain due to the area's complexity, but this study is a starting point to better understand the steps for the reconstruction of the system. |
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