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Petrology and Geochemistry of Recent Lavas from Santo Antão (Cape Verde Islands)

dc.contributor.authorHenriques, S.B.A.
dc.contributor.authorMunhá, José
dc.contributor.authorSilva, L. Celestino da
dc.contributor.authorMendes, M. H.
dc.date.accessioned2020-12-18T12:39:35Z
dc.date.available2020-12-18T12:39:35Z
dc.date.issued2005-04
dc.date.updated2020-12-15T17:58:58Z
dc.description.abstractABSTRACT: Santo Antão Island is the northernmost island of the Cape Verde Archipelago that is located in the Atlantic Ocean between 17º 13’N-14º 48’N and 22º 42’W-25º 22’W. The genesis of this Archipelago is explained by the activity of a hot-spot, which began 25 My ago. The main stratigraphic sequences of Santo Antão island (Silva et al., 1994; 2004) have been dated by Plesner et al. (2003) and comprise, from base to top, the “Complexo Eruptivo Antigo” (7.57 ± 0.56 My) the “Formação Conglomerático-Brechóide”, the “Formação Eruptiva Principal” (3.24 ± 0.89 to 0.22 ± 0.03 My) (which is overlain by a white phonolitic deposit pumice) and the “Formação Eruptiva do Tope de Coroa” (0.17 ± 0.02 My to 0.09 ± 0.03 My). The “Complexo Eruptivo Antigo” includes chiefly basaltic flows. The “Formação Conglomerático-Brechóide” is a sedimentary unit formed during an intensive erosion period and was followed by an important volcanic event, represented by the “Formação Eruptiva Principal”, comprising nephelinitic, phonolitic, tephritic and basanitic lava flows. The “Formação Eruptiva do Tope de Coroa”, the most recent unit of the island, was divided (Silva et al. 2004) into three sub-units (figure 1): “Sequência Antiga”, “Sequência Intermédia” and “Sequência Superior”. The “Sequência Antiga” is composed by phonolitic and nephelinitic flows and scorias, the “Sequência Intermédia” comprises basaltic flows and scorias and the “Sequência Superior” includes basaltic, phonolitic and nephelinitic flows and scorias. Santo Antão recent lavas are silica undersaturated (carrying abundant feldspathoids, particularly hauyne), alkaline and considerably evolved (Mg#=13-53 wt%, Ni=0-252 ppm, Cr=0-434 ppm). They display a strong enrichment in incompatible trace elements, suggesting that their primary magmas were produced by low degrees of partial melting, from a heterogeneous, metassomatized, source (including residual garnet and phlogopite), with a significant HIMU component.pt_PT
dc.description.versioninfo:eu-repo/semantics/publishedVersionpt_PT
dc.identifier.citationHenriques, S... [et.al.] - Petrology and Geochemistry of Recent Lavas from Santo Antão (Cape Verde Islands). In: Sal2005: Book of Abstract of International Workshop on Ocean Island Volcanism, 2005, p. 58-59pt_PT
dc.identifier.slugcv-prod-805282
dc.identifier.urihttp://hdl.handle.net/10400.9/3524
dc.language.isoengpt_PT
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/pt_PT
dc.subjectPetrologiapt_PT
dc.subjectGeoquímicapt_PT
dc.subjectLavaspt_PT
dc.subjectilha de Santo Antão (Arquipélago de Cabo Verde)pt_PT
dc.titlePetrology and Geochemistry of Recent Lavas from Santo Antão (Cape Verde Islands)pt_PT
dc.typeconference object
dspace.entity.typePublication
oaire.citation.endPage59pt_PT
oaire.citation.startPage58pt_PT
oaire.citation.titleSal2005 International Workshop on Ocean Island Volcanismpt_PT
person.familyNameHenriques
person.givenNameSusana Branco dos Anjos
person.identifier.ciencia-idD517-B389-532D
person.identifier.orcid0000-0001-6336-570X
rcaap.cv.cienciaidD517-B389-532D | Susana Branco dos Anjos Henriques
rcaap.rightsopenAccesspt_PT
rcaap.typeconferenceObjectpt_PT
relation.isAuthorOfPublication85a8667f-c112-4a14-a7b6-53153dc8c74a
relation.isAuthorOfPublication.latestForDiscovery85a8667f-c112-4a14-a7b6-53153dc8c74a

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