Data/hora: 12/06/2024 00:44:08

Provedor de dados: 	Institutional Archive of Ifreme (ArchiMer)	
País: 	France	
Título: 	Helium isotopes on the Pacific-Antarctic ridge (52.5°–41.5°S)	
Autores: 	Moreira, M; Dosso, Laure; Ondreas, Helene.	
Data: 	2008-05	
Ano: 	2008	
Palavras-chave: 	Pacific Antarctic ridge; Mantle geochemistry; Helium isotopes.	
Resumo: 	The first isotopic data and concentrations of helium are reported for the Pacific-Antarctic ridge between 52.5 degrees S and 41.5 degrees S. The He-4/He-3 ratio is extremely homogeneous over more than 1200 km, with a mean ratio of 99,275 (R/Ra = 7.29) and a standard deviation of 2719 (0.19), which is the lowest dispersion observed for the global mid oceanic ridge system. Moreover, the Menard T. F. is a frontier between two mantles with slightly different helium isotopic ratios (96,595 +/- 1520 and 100,347 +/- 2330). No difference in the helium concentration between the two ridge segments defined by the Menard T. F. can be observed, as well as no significant difference in the U and Th contents suggesting that the difference in helium isotopic ratio is old (&gt;500 My) and may represent a slight difference in degassing or/and trace element depletion history.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	http://archimer.ifremer.fr/doc/2008/publication-4348.pdf

DOI:10.1029/2008GL033286	
Editor: 	American Geophysical Union	
Relação: 	http://archimer.ifremer.fr/doc/00000/4348/	
Formato: 	application/pdf	
Fonte: 	Geophysical Research Letters (0094-8276) (American Geophysical Union), 2008-05 , Vol. 35 , N. 10 , P. NIL_49-NIL_54	
Fonte: 	2008 American Geophysical Union