Campo DC | Valor | Idioma |
dc.contributor.author | Plá Cid, J. | - |
dc.contributor.author | Nardi, L. V. S. | - |
dc.contributor.author | Conceição, Hebert | - |
dc.contributor.author | Bonin, Bernard | - |
dc.contributor.author | Sá, E. F. Jardim de | - |
dc.creator | Plá Cid, J. | - |
dc.creator | Nardi, L. V. S. | - |
dc.creator | Conceição, Hebert | - |
dc.creator | Bonin, Bernard | - |
dc.creator | Sá, E. F. Jardim de | - |
dc.date.accessioned | 2013-11-01T11:53:44Z | - |
dc.date.issued | 2000 | - |
dc.identifier.issn | 0895-9811 | - |
dc.identifier.uri | http://repositorio.ufba.br/ri/handle/ri/13478 | - |
dc.description | Texto completo. Acesso restrito. p. 661–683 | pt_BR |
dc.description.abstract | The Neoproterozoic of northeastern Brazil was marked by the development of collisional fold belts, mainly surrounding the Sa˜o Francisco
Craton, and an associated widespread granitic magmatism. The Casa Nova 555 ^ 10 Ma; Sri 0:7068 and Engrac¸adinha syenites and
granites, intrusive in the Riacho do Pontal Fold Belt, are related to the late stages of this collisional event. Melanocratic syenites, probably
generated by magmatic-flow cumulate processes, and mesocratic and leucocratic syenites, representing magmatic liquids, are associated with
granites, pegmatites, and syenite–granite dykes. Homogeneous or perthitic alkali feldspar, quartz, aegirine–augite, diopside, titanite, apatite,
magnesian biotite, winchite–richterite, and magnetite are the dominant mineral phases. It is suggested that these magmas belong to an
ultrapotassic silica-saturated alkaline series, defined on the basis of its alkaline, silica-saturated character and by a K2O/Na2O ratio of .3.0
— that is, intermediate. Major- and trace-element evolution is consistent with mineral fractionation processes, controlled by magmatic flow,
and dominated by apatite–titanite–pyroxene in the less differentiated terms and by alkali feldspar in the more evolved. The source of primary
magmas is a previously subduction-metasomatised mantle, probably with anomalous enrichment in LREE and LILE elements. Barite–
ilmenite mineralisations are related to the more differentiated Engrac¸adinha granites. | pt_BR |
dc.language.iso | en | pt_BR |
dc.publisher | Journal of South American Earth Sciences | pt_BR |
dc.rights | Acesso Aberto | pt_BR |
dc.source | http://dx.doi.org.ez10.periodicos.capes.gov.br/10.1016/S0895-9811(00)00047-X | pt_BR |
dc.subject | Ultrapotassic magmatism | pt_BR |
dc.subject | Syenites | pt_BR |
dc.subject | Geochemistry | pt_BR |
dc.title | The alkaline silica-saturated ultrapotassic magmatism of the Riacho do Pontal Fold Belt, NE Brazil: an example of syenite–granite Neoproterozoic association | pt_BR |
dc.title.alternative | Journal of South American Earth Sciences | pt_BR |
dc.type | Artigo de Periódico | pt_BR |
dc.description.localpub | Salvador | pt_BR |
dc.identifier.number | v. 13, n. 7 | pt_BR |
dc.embargo.liftdate | 10000-01-01 | - |
Aparece nas coleções: | Artigo Publicado em Periódico (IGEO)
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