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Reconstructing the architectural evolution of volcanic islands from combined K/AR, morphologic, tectonic, and magnetic data. The Faial Island exemple (Azores)

2012-10-01Journal article Restricted access
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dc.contributor.authorHildenbrand, A.
dc.contributor.authorMarques, Fernando O.
dc.contributor.authorCosta, A. C. G.
dc.contributor.authorSibrant, A. L. R.
dc.contributor.authorSilva, Pedro
dc.contributor.authorHenry, B.
dc.contributor.authorMIRANDA, JORGE MIGUEL
dc.contributor.authorMadureira, P.
dc.date.accessioned2015-09-07T09:04:51Z
dc.date.available2015-09-07T09:04:51Z
dc.date.issued2012-10-01
dc.description.abstractThe 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 topography at successive stages, in response to complex interactions between volcanic construction and mass wasting, including the development of a graben. We show that: (1) sub-aerial evolution of the island first involved the rapid growth of a large elongated volcano at ca. 0.85 Ma, followed by its partial destruction over half a million years; (2) beginning about 360 ka a new small edifice grew on the NE of the island, and was subsequently cut by normal faults responsible for initiation of the graben; (3) after an apparent pause of ca. 250 kyr, the large Central Volcano (CV) developed on the western side of the island at ca 120 ka, accumulating a thick pile of lava flows in less than 20 kyr, which were partly channelized within the graben; (4) the period between 120 ka and 40 ka is marked by widespread deformation at the island scale, including westward propagation of faulting and associated erosion of the graben walls, which produced sedimentary deposits; subsequent growth of the CV at 40 ka was then constrained within the graben, with lava flowing onto the sediments up to the eastern shore; (5) the island evolution during the Holocene involves basaltic volcanic activity along the main southern faults and pyroclastic eruptions associated with the formation of a caldera volcano-tectonic depression. We conclude that the whole evolution of Faial Island has been characterized by successive short volcanic pulses probably controlled by brief episodes of regional deformation. Each pulse has been separated by considerable periods of volcanic inactivity during which the Faial graben gradually developed. We propose that the volume loss associated with sudden magma extraction from a shallow reservoir in different episodes triggered incremental downward graben movement, as observed historically, when immediate vertical collapse of up to 2 m was observed along the western segments of the graben at the end of the Capelinhos eruptive crises (1957-58).por
dc.identifier.citationHILDENBRAND, A.; [et al] - Reconstructing the architectural evolution of volcanic islands from combined K/AR, morphologic, tectonic, and magnetic data: The Faial Island exemple (Azores). Journal of Volcanology and Geothermal Research. ISSN: 0377-0273. Vol. 241-242 (2012), pp. 39-48.
dc.identifier.doi10.1016/j.jvolgeores.2012.06.019
dc.identifier.issn0377-0273
dc.identifier.urihttp://hdl.handle.net/10400.21/5061
dc.language.isoengpor
dc.peerreviewedyespor
dc.publisherElsevier Science BVpor
dc.relationPOCTI/CTE/48137/2002 - TEAMINT
dc.relationPTDC/CTE-GIX/108149/2008 - MEGAHazards
dc.relationPTDC/CTE-GIN/71838/2006 - Project EVOLV
dc.subjectFaialpor
dc.subjectVolcanic constructionpor
dc.subjectMass-wastingpor
dc.subjectK/Arpor
dc.subjectTectonicspor
dc.subjectMagnetismpor
dc.subjectAzores triple junctionpor
dc.titleReconstructing the architectural evolution of volcanic islands from combined K/AR, morphologic, tectonic, and magnetic data. The Faial Island exemple (Azores)por
dc.typejournal article
dspace.entity.typePublication
oaire.citation.endPage48por
oaire.citation.startPage39por
oaire.citation.titleJournal of Volcanology and Geothermal Researchpor
oaire.citation.volume241-242por
person.familyNameSilva
person.familyNameMIRANDA
person.givenNamePedro
person.givenNameJORGE MIGUEL
person.identifier1232178
person.identifier1644327
person.identifier.ciencia-idC314-1157-FD0C
person.identifier.ciencia-idED1A-8CC7-06DB
person.identifier.orcid0000-0002-9178-3623
person.identifier.orcid0000-0002-1321-8709
person.identifier.ridB-8512-2008
person.identifier.ridB-5287-2008
person.identifier.scopus-author-id55431034700
person.identifier.scopus-author-id7202982159
rcaap.rightsclosedAccesspor
rcaap.typearticlepor
relation.isAuthorOfPublication54c96e27-8c3a-42d9-b751-ebc637c2f478
relation.isAuthorOfPublication6949869a-9af7-4284-ac56-85747a2dfa45
relation.isAuthorOfPublication.latestForDiscovery6949869a-9af7-4284-ac56-85747a2dfa45

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