Duarte, João Daniel Casal, 1981-Pereira, Ricardo N.Araújo, Bruno Miguel Duarte de2024-02-142024-02-1420232023http://hdl.handle.net/10451/62615Tese de mestrado, Geologia Estrutural, 2023, Universidade de Lisboa, Faculdade de CiênciasFor over a century, the investigation of Late Cretaceous alkaline magmatism in the Western Iberian Margin (WIM) has focused on individual massifs, notably the Monchique massif, revealing unique rock types like Foyaite and Monchiquites (Blum, 1861; Hunter & Rosenbusch, 1890; Rock, 1982). Despite these studies, integrating these occurrences into a comprehensive geodynamic and mantle source framework has remained challenging. Existing analyses often treated them as isolated entities, relying on age dating and geochemical profiles (Grange et al., 2008, 2010; Martins et al., 2010; Mata et al., 2015; Miranda et al., 2009; Neres et al., 2012, 2018). To establish correlations among these discrete magmatic events, a paleogeographic reconstruction model was executed via GPlates software. This tool enabled the exploration of tectonic plate positions over time, coupled with underlying mantle dynamics, seeking explanations for the non-linear distribution and varied timing of magmatism in the WIM. Three primary hypotheses were evaluated: a static or mobile Hot Spot model (Courtillot et al., 2003; Elder, 1976; Koppers, 2011; Morgan, 1971, 1972), the Superplume magmatism hypothesis (Civiero et al., 2021; Courtillot et al., 2003; Long et al., 2020), and Edge-Driven Convection (King, 2007; King & Anderson, 1998; King & Ritsema, 2000; Matton & Jébrak, 2009; Missenard & Cadoux, 2012). Results indicate that a persistent and robust Super Plume better explains the distinct magmatic instances in the Western Iberian Margin than the Hot Spot theory. Edge-Driven Convection is deemed improbable due to a lack of conditions for initiation. Motion paths were analysed to validate or refute these hypotheses, including alignments like Tore-Sintra-Sines-Monchique, Tore-Madeira, and Monchique-Gorringe-Madeira. However, these paths were adjusted to better reflect regional geodynamics. Notably, specific motion paths, such as the Lisbon Volcanic Complex, hint at the potential interconnection of all WIM intrusions, with overlapping patterns suggesting the magmatic plumbing in locations and time frames matching the intrusion of these formations. Moreover, the study suggests a potential link between the Madeira Archipelago and other seamounts like Ampère, Seine, and Unicorn, such as seen in the Ampère motion path. This research demonstrates the complex interplay of geological and geodynamic processes shaping the magmatic history of the Western Iberian Margin, shedding light on the intricate relationships between magmatic occurrences and tectonic processes.engMagmatismo Tardi-CretácicoMargem Oeste IbéricaReconstruções PaleogeográficasTectónica de PlacasGPlatesTeses de mestrado - 2023master thesis203525140