The emergence of volcanic oceanic islands on a slow-moving plate: the example of Madeira Island, NE Atlantic

Ramalho, Ricardo S.; Silveira, António Brum da; Fonseca, Paulo E.; Madeira, José; Cosca, Michael; Cachão, Mário; Fonseca, Maria M.; Prada, Susana N.; PRADA, SUSANA

Publication

The emergence of volcanic oceanic islands on a slow-moving plate: the example of Madeira Island, NE Atlantic

2015-02Journal article

datacite.subject.fos	Ciências Naturais::Ciências da Terra e do Ambiente
dc.contributor.author	Ramalho, Ricardo S.
dc.contributor.author	Silveira, António Brum da
dc.contributor.author	Fonseca, Paulo E.
dc.contributor.author	Madeira, José
dc.contributor.author	Cosca, Michael
dc.contributor.author	Cachão, Mário
dc.contributor.author	Fonseca, Maria M.
dc.contributor.author	Prada, Susana N.
dc.contributor.author	PRADA, SUSANA
dc.date.accessioned	2025-11-20T15:47:31Z
dc.date.available	2025-11-20T15:47:31Z
dc.date.issued	2015-02
dc.description.abstract	<jats:title>Abstract</jats:title><jats:p>The transition from seamount to oceanic island typically involves surtseyan volcanism. However, the geological record at many islands in the NE Atlantic—all located within the slow‐moving Nubian plate—does not exhibit evidence for an emergent surtseyan phase but rather an erosive unconformity between the submarine basement and the overlying subaerial shield sequences. This suggests that the transition between seamount and island may frequently occur by a relative fall of sea level through uplift, eustatic changes, or a combination of both, and may not involve summit volcanism. In this study, we explore the consequences for island evolutionary models using Madeira Island (Portugal) as a case study. We have examined the geologic record at Madeira using a combination of detailed fieldwork, biostratigraphy, and <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/ggge20671-math-0001.png" xlink:title="urn:x-wiley:15252027:media:ggge20671:ggge20671-math-0001" /> geochronology in order to document the mode, timing, and duration of edifice emergence above sea level. Our study confirms that Madeira's subaerial shield volcano was built upon the eroded remains of an uplifted seamount, with shallow marine sediments found between the two eruptive sequences and presently located at 320–430 m above sea level. This study reveals that Madeira emerged around 7.0–5.6 Ma essentially through an uplift process and before volcanic activity resumed to form the subaerial shield volcano. Basal intrusions are a likely uplift mechanism, and their emplacement is possibly enhanced by the slow motion of the Nubian plate relative to the source of partial melting. Alternating uplift and subsidence episodes suggest that island edifice growth may be governed by competing dominantly volcanic and dominantly intrusive processes.</jats:p>	eng
dc.identifier.citation	Ramalho, R. S., A. Brum da Silveira, P. E. Fonseca, J. Madeira, M. Cosca, M. Cach~ao, M. M. Fonseca, and S. N. Prada (2015), The emergence of volcanic oceanic islands on a slow moving plate: The example of Madeira Island, NE Atlantic, Geochem. Geophys. Geosyst., 16, 522–537, doi:10.1002/ 2014GC005657.
dc.identifier.doi	10.1002/2014gc005657
dc.identifier.issn	1525-2027
dc.identifier.issn	1525-2027
dc.identifier.uri	http://hdl.handle.net/10400.13/7476
dc.language.iso	eng
dc.peerreviewed	yes
dc.publisher	American Geophysical Union (AGU)
dc.relation	LA-0019 IDL
dc.relation.ispartof	Geochemistry, Geophysics, Geosystems
dc.rights.uri	http://creativecommons.org/licenses/by/4.0/
dc.subject	Volcanic oceanic islands
dc.subject	Madeira Island (Portugal)
dc.subject	Geology
dc.subject	Vulcanism
dc.subject	.
dc.subject	Faculdade de Ciências Exatas e da Engenharia
dc.title	The emergence of volcanic oceanic islands on a slow-moving plate: the example of Madeira Island, NE Atlantic	eng
dc.type	journal article
dspace.entity.type	Publication
oaire.citation.endPage	537
oaire.citation.issue	2
oaire.citation.startPage	522
oaire.citation.title	Geochemistry, Geophysics, Geosystems
oaire.citation.volume	16
oaire.version	http://purl.org/coar/version/c_970fb48d4fbd8a85
person.familyName	PRADA
person.givenName	SUSANA
person.identifier.orcid	0000-0003-4050-8186
relation.isAuthorOfPublication	56cda262-2033-4f1e-95a3-7aeefd019f39
relation.isAuthorOfPublication.latestForDiscovery	56cda262-2033-4f1e-95a3-7aeefd019f39