| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
40 AR/39 AR ages for the alkaline volcanism and the basement of Gorringe Bank, North atlantic Ocean
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| Autores: |
Feraud, Gilbert
Gastaud, Janine
Auzende, Jean-marie
Olivet, Jean-louis
Cornen, Guy
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| Data: |
1981-08
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| Ano: |
1981
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| Palavras-chave: |
Histoire Ifremer
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| Resumo: |
Gorringe Bank is situated on the Europe-Africa plate boundary at the eastern end of the Azores-Gibraltar fracture zone. It has two summits. Gettysburg Bank to the southwest and Ormonde Bank to the northeast. We applied the 40Ar/39AR stepwise heating method to date six samples of the alkaline volcanic rocks. Two gabbros from the Ormonde Bank and a dolerite from the Gettysburg Bank. The results suggest that the alkaline volcanism lasted probably for less than 6 Ma(66-60 Ma). Although the nature of this volcanism precludes any subduction feature during its setting. the alkaline volcanism of Ormonde is probably linked to Upper Cretaceous/Eocene compressive tectonic events. The basement rocks of Gorringe Bank reveal disturbed 40Ar/39Ar age spectra. One plagioclase and one biotite from a gabbrogive evidence for a thermic event whose age is tentatively estimated al about 75 Ma, and relared to a variation in the direction of the relative movement between Europe and Africa. The more probable age given by a plagioclase of another gabbro and by a dolerite (110 Ma) corresponds to tilting northeastward of the Gorringe massif. [NOT CONTROLLED OCR]
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
http://archimer.ifremer.fr/doc/1981/publication-5365.pdf
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| Relação: |
http://archimer.ifremer.fr/doc/00000/5365/
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| Formato: |
application/pdf
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| Fonte: |
Earth and Planetary Science Letters, 1981-08 , Vol. 57 , N. 1 , P. 459-474
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| Direitos: |
Centre Océanologique de Bretagne
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