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Helium isotope ratios

Poreda, R., Craig, H. (1989) Helium isotope ratios in circum-Pacific volcanic arcs. Nature, 338, 473-8. [Pg.272]

Sano, Y., Wakita, H. (1987) Island arc tectonics of New Zealand manifested in helium isotope ratios. Geochim. Cosmochim. Acta, 51, 1855-69. [Pg.273]

Busemann H., Baur H., and Wieler R. (2001) Helium isotopic ratios in carbonaceous chondrites significant for the early solar nebula and circumstellar diamonds Lunar Planet. Sci. XXXII, 1598. Lunar and Planetary Institute, Houston (CD-ROM). [Pg.404]

Measurements of xenon in high He/" He OIB samples have often found atmospheric isotopic ratios (e.g., Allegre et al, 1983) that appear to be due to overwhelming air xenon contamination (Harrison effll., 1999 Patterson efal., 1990) rather than reflecting mantle xenon with an air composition. Although Samoan samples with intermediate (9-20Ra) helium isotope ratios have been found with xenon isotopic ratios distinct from those of the atmosphere (Poreda and Farley, 1992), the xenon in these samples may have been derived largely from the MORB source. Harrison et al. [Pg.992]

Extensive volcanism can be found in eastern Africa associated with the East African rift system. Helium isotope ratios measured in basalts from the Ethiopian Rift Valley and Afar, near the triple junction of Red Sea, Aden, and Ethiopian rift systems, are 6-17/ a (Marty et al., 1993, 1996 Scarsi and Craig, 1996). These values include MORB ratios as well as indications of both contributions from radiogenic He and high He/ He hotspots. To the south, the rift system divides into eastern and western branches. Xenoliths from Tanzanian vents in the eastern branch... [Pg.1010]

Hilton D. R., Maepherson C. G., and Elliott T. R. (2000a) Helium isotope ratios in mahe phenocrysts and geothermal fluids from La Palma, the Canary Islands (Spain) implications for HIMU mantle sources. Geochim. Cosmochim. Acta 64, 2119-2132. [Pg.1015]

Scarsi P. and Craig H. (1996) Helium isotope ratios in Ethiopian rift basalts. Earth Planet. Sci. Lett. 144, 505—516. [Pg.1018]

Bodmer P, Bochsler P (1998b) The helium isotopic ratio in the solar wind and ion fractionation in the corona by inefficient Coulomb drag. Astron Astrophys 337 921-927 Bogard DD (1988) On the origin of Venus atmosphere possible contributions from simple component mixtures and fractionated solar wind. Icarus 74 3-20... [Pg.64]

Craig H, Lupton JE, Welhan JA, Poreda R (1978) Helium isotope ratios in Yellowstone and Lassen Park volcanic gases. Geophys Res Lett 5 897-900... [Pg.307]

Poreda RJ, Schilhng J-G, Craig H (1993) Helium isotope ratios in Easter Microplate basalts. Earth Planet Sci Lett 119 319-329... [Pg.314]

Scarsi P (2000) Fractional extraction of helinm by crashing of olivine and clinopyroxene phenociysts effects on the He/ He measured ratio. Geochim Cosmochim Acta 64 3751-3762 Scarsi P, Craig H (1996) Helium isotope ratios in Ethiopian Rift basalts. Earth Planet Sci Lett 144 505-516... [Pg.315]

Sano Y, Wakita H, Giggenbach WF (1987) Island arc tectonics of New Zealand manifested in helium isotope ratios. Geochim Cosmochim Acta 51 1855-1860 Sano Y, Nakamura Y, Notsu K, Wakita H (1988) Influence of volcanic eruptions on helium isotope ratios in hydrothermal systems induced by volcanic eraptions. Geochim Cosmochim Acta 52 1305-1308 Sano Y, Wakita H, Italiano F, Nuccio MP (1989) Helium isotopes and tectonics in southern Italy. Geophys Res Lett 16 511-514... [Pg.368]

Sano Y, Notsu K, Ishibashi J, Igarashi G, Wakita H (1991) Secular variations in helium isotope ratios in an active volcano Eruption and plug hypothesis. Earth Planet Sci Lett 107 95-100 Sano Y, Hirabayashi J, Oba T, Gamo T (1994) Carbon and helium isotopic ratios at Kusatsu-Shirane volcano, Japan. Appl Geochem 9 371-377... [Pg.368]

Eor samples highly enriched in helium such as volcanic rocks and hydrothermal vent fluids, the helium isotope ratio is usually expressed in the R/Ra notation described above. However, for the relatively small variations observed in sea water samples, the He/" He variations are usually expressed as i5( He), which is the percentage deviation from the ratio in air, defined as in eqn [1]. [Pg.147]

Fig. 4. (a) 6 C(CH4) vs. relationship for Taranaki natural gases helium isotopic ratios... [Pg.73]

See other pages where Helium isotope ratios is mentioned: [Pg.137]    [Pg.148]    [Pg.132]    [Pg.980]    [Pg.303]    [Pg.316]    [Pg.279]    [Pg.95]    [Pg.64]    [Pg.97]    [Pg.255]    [Pg.329]    [Pg.334]    [Pg.404]    [Pg.535]    [Pg.596]    [Pg.643]    [Pg.709]    [Pg.710]    [Pg.71]   
See also in sourсe #XX -- [ Pg.304 , Pg.306 , Pg.307 ]



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