Helium isotopic systematics within the neovolcanic zones of Iceland
Date of Original Version
Helium isotopic compositions have been measured in a suite of sub-glacial basaltic glasses from the neovolcanic zones of Iceland. The 3He/4He ratios vary between 8 and 26.2× atmospheric; the higher ratios are generally consistent with a relatively primitive undegassed mantle source for the helium. Several sampling tests indicate that sub-glacial basaltic glasses retain a representative sample of magmatic helium, much like mid-ocean ridge basalts. The overall variations, high observed helium concentrations (up to 1.6×10-6 cm3 STP/g), and young age of Icelandic crust argue strongly against crustal contamination as a primary control of helium isotopes in the basaltic lavas. Each volcanic zone has a distinctive basaltic 3He/4He isotopic signature: 18-26.2× atmospheric in the eastern volcanic zone and central Iceland, 12-16× atmospheric in the western volcanic zone, and 8-11 in the northeastern volcanic zone. The limited range of 3He/4He ratios within each zone, variability between volcanic zones in 3He/4He, and temporal aspects of Icelandic volcanism are interpreted within the framework of a plume model for the mantle beneath Iceland. The preferred model involves variable contributions from a plume source (i.e. undegassed) to each of the Icelandic volcanic zones. The fact that the highest 3He/4He ratios are observed in eastern and central Iceland suggests that volcanism in these areas has the greatest contribution from the plume. © 1985 Elsevier Science Publishers B.V.
Publication Title, e.g., Journal
Earth and Planetary Science Letters
Kurz, Mark D., Peter S. Meyer, and Haraldur Sigurdsson. "Helium isotopic systematics within the neovolcanic zones of Iceland." Earth and Planetary Science Letters 74, 4 (1985). doi: 10.1016/S0012-821X(85)80001-7.