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Reply to the comment by Quartau and Mitchell on “Reconstructing the architectur...
Hildenbrand, Anthony; Marques, Fernando; Costa, A.; Sibrant, A.; Silva, Pedro; Henry, Bernard; Miranda, Jorge Miguel; Madureira, PedroReply to the comment by Quartau and Mitchell on “Reconstructing the architectural evolution of volcanic islands from combined K/Ar, morphologic, tectonic, and magnetic data: The Faial Island example (Azores)”, J. Volcanol. Geotherm. Res. 241–242, 39–48, by Hildenbrand et al. (2012)
Mantle dynamics and characteristics of the Azores plateau
Adam, Claudia; Madureira, Pedro; Miranda, Jorge Miguel; Lourenço, Nuno; Yoshida, M.; Fitzenz, DelphineSituated in the middle of the Atlantic Ocean, the Azores plateau is a region of elevated topography encompassing the triple junction between the Eurasian, Nubian and North American plates. The plateau is crossed by the Mid-Atlantic Ridge, and the Terceira Rift is generally thought of as its northern boundary. The origin of the plateau and of the Terceira Rift is still under debate. This region is associated wit...
Magma Signatures in the Terceira Rift Azores: a melt inclusion study
Marques, Ana Filipa; Zajacz, Zoltan; Madureira, Pedro; Scott, StevenThe Terceira Rift (TR) is a 550km long ESE trending line of volcanic reliefs (Graciosa Island, Terceira Island, D. João de Castro Bank, S. Miguel Island) alternating with deep basins (e.g. E of Terceira, Hirondelle) that define the plate boundary between the European and African plates on the Azores plateau [1]. Seismic tomography suggests that the Azores plume is centered NE of Terceira supplying upwelling plu...
Palaeomagnetic study of a subaerial volcanic ridge (S˜ao Jorge Island, Azores) ...
Silva, Pedro; Henry, Bernard; Marques, Fernando; Hildenbrand, Anthony; Madureira, Pedro; Mériaux, Catherine; Kratinová, ZusanaWe present a palaeomagnetic study on 38 lava flows and 20 dykes encompassing the past 1.3 Myr on S. Jorge Island (Azores Archipelago—North Atlantic Ocean). The sections sampled in the southeastern and central/western parts of the island record reversed and normal polarities, respectively. They indicate a mean palaeomagnetic pole (81.3◦N, 160.7◦E, K = 33 and A95 = 3.4◦) with a latitude shallower than that expect...
Geochemical evidence for melting of carbonated peridotite on Santa Maria Island...
Beier, Christoph; Mata, João; Stöckhert, Ferdinand; Mattielli, Nadine; Brandl, Philipp; Madureira, Pedro; Genske, Felix; Martins, Sofia; Madeira, JoséThe islands of the Azores archipelago emerge from an oceanic plateau built on lithosphere increasing in age with distance from the Mid-Atlantic Ridge from 10 to 45 Ma. Here, we present the first comprehensive major and trace element and Sr–Nd–Pb isotope data from Santa Maria, the easternmost island of the archipelago, along with published data from the other Azores islands situated much closer to the Mid-Atlant...
Reconstructing the architectural evolution of volcanic islands from combined K/...
Hildenbrand, Anthony; Marques, Fernando; Costa, A.; Sibrant, A.L.R.; Silva, Pedro; Henry, Bernard; Miranda, Jorge; Madureira, PedroThe morpho-structural evolution of oceanic islands results from competition between volcano growth and partial destruction by mass-wasting processes. We present here a multi-disciplinary study of the successive stages of development of Faial (Azores) during the last 1 Myr. Using high-resolution digital elevation model (DEM), and new K/Ar, tectonic, and magnetic data, we reconstruct the rapidly evolving topograp...
Helium and neon isotopes in São Miguel island basalts, Azores Archipelago: New ...
Moreira, Manuel; Kanzari, Aisha; Madureira, PedroLavas from the São Miguel Island, Azores Archipelago, have peculiar isotopic compositions, including radiogenic lead and strontium and un-radiogenic neodymium. The peculiar isotopic trend of São Miguel is evident in the lead-lead diagram where both 207Pb/204Pb and 208Pb/204Pb ratios are high for a given 206Pb/204Pb ratio compared to other oceanic island basalts. This signature is unique among OIBs and is partic...
Reconstructing the architectural evolution of volcanic islands from combined K/...
Hildenbrand, Anthony; Marques, Fernando; Costa, A.C.G.; Sibrant, A.L.R.; SIlva, Pedro; Henry, Bernard; Miranda, Miguel; Madureira, PedroThe morpho-structural evolution of oceanic islands results from competition between volcano growth and partial destruction by mass-wasting processes. We present here a multi-disciplinary study of the successive stages of development of Faial (Azores) during the last 1 Myr. Using high-resolution digital elevation model (DEM), and new K/Ar, tectonic, and magnetic data, we reconstruct the rapidly evolving topograp...
Mantle dynamics and volcanism emplacement in the Azores
Adam, Claudia; Lourenço, Nuno; Madureira, Pedro; Miranda, Miguel; Yoshida, M.The Azores plateau is a triangular shaped topographic feature encompassing the boundary zone where three major tectonic plates (EU, NU and NA) meet. The eastern side of the plateau is delimited by two major tectonic discontinuities: the Mid Atlantic Ridge, and the Terceira Rift, a recently formed ultra-slow-spreading ridge. The origin of the plateau is still under debate. One hypothesis argues that the plateau ...
The Terceira Rift, Azores: a melt inclusion study of submarine lavas
Marques, Filipa; Scott, Steve; Madureira, Pedro; Conceição, Patrícia; Lourenço, Nuno; Rosa, CarlosThe Azores plateau, a bathymetric high, is seated on an anomalous mantle domain located in the Azores Triple Junction where the American, EUR and AFR lithospheric plates meet. The cause for these anomalies is controversial but many authors consider the presence of an anomalously hot/wet enriched mantle probably supplied by a plume [3]. The origin, size and present location of the plume is under debate but an ar...
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