Other
Scientific paper
Sep 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994jgr....9917709b&link_type=abstract
Journal of Geophysical Research (ISSN 0148-0227), vol. 99, no. B9, p. 17,709-17,715
Other
9
Argon Isotopes, Basalt, Contamination, Helium Isotopes, Magma, Planetary Geology, Argon, Carbon Dioxide, Crushing, Degassing, Earth Mantle, Mid-Ocean Ridges, Neodymium Lasers, Olivine
Scientific paper
Combined mass spectrometric and manometric techniques permit simultaneous analysis of noble gases amd major volatiles from the same sample extraction. He, Ar, and CO2 data of inclusion- and vesicle-trapped fluids from two high He-3/He-4 islands (Reunion and Iceland) presented here show that air contamination is probably present in all trapped fluids and that the Ar-36 content of high He-3/He-4 mantle volatiles is low. The least contaminated fluid compositions indicates a Ar-36 abundance in these fluids (CO2/Ar-36 = 2.7 x 10(exp 8)) indistinguishable from published mid-ocean ridge basalt (MORB) values. Although the high Ar-40/Ar-36 ratio of the uncontaminated fluids (approximately equals 2000) may be due to incorporation of radiogenic Ar (derived from Morb volatiles or the overlying crust), it is likely that high Ar-40/Ar-36 ratios are characteristic of the high He-3/HJe-4 mantle source region. Degassing of primordial Ar-36 from the source region must have occurred while retaining a primordial He component. Helium isotope ratios, Ar-40/Ar-36, and CO2/Ar-36 of olivines entrained in Icelandic picrite glasses support pertrographic evidence for their origin as lower crustal material entrained by the picrite magma. It is probable that olivine 'phenocrysts' from other oceanic islands (e.g., Reunion) are similarly unrelated to their host lavas and that cumulate or xenolith phases may represent more suitable 'bottles' of mantle volatiles.
Burnard Pete G.
Oskarsson Niels
Stuart Finlay M.
Turner Gary
No associations
LandOfFree
Air contamination of basaltic magmas: Implications for high He-3/He-4 mantle Ar isotopic composition does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Air contamination of basaltic magmas: Implications for high He-3/He-4 mantle Ar isotopic composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Air contamination of basaltic magmas: Implications for high He-3/He-4 mantle Ar isotopic composition will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1791490