Podrobnosti záznamu

    Combined Li-He isotopes in Iceland and Jan Mayen basalts and constraints on the nature of the North Atlantic mantle
    Halliday, Alexander
    Harrison, Darrell
    Magna, Tomáš
    Stuart, Finlay
    Wiechert, Uwe
Typ dokumentu
    článek v periodiku
Zdrojový dokument - seriál
    Geochimica et Cosmochimica Acta
    Roč. 75, č. 3
Výraz tezauru
    lithium isotopes, helium isotopes, Iceland, Jan Mayen, recycling, mantle
Klíčové slovo
Abstrakt (anglicky)
   Basaltic glasses from the Hengill fissure system, Iceland, define an inverse trend in d7Li vs. 3He/4He space. The highest 3He/4He of 20 RA is associated with "normal" mantle d7Li of 3.8?. Despite light O isotope compositions and positive Eu and Nb anomalies, the high-3He/4He component carries no evident Li isotope trace of being the product of recycling of altered slab or wedge material. The high d7Li (>6.9?) component with lower 3He/4He includes samples with elevated Nb/U, Sr/Nd and excess Eu providing evidence of a cumulate enriched source that may also be part of an ancient altered ocean floor slab. Jan Mayen basalts (d7Li=3.9-4.7?) are characterized by large degrees of enrichment in ITE providing evidence for a third source with EM-like characteristics. Therefore, oceanic basalts can display a wide range in He isotope compositions, and trace element compositions, associated with recycled components whilst exhibiting no sign of surface-altered slab or wedge material from the Li isot
   ope composition.
    Česká geologická služba
Kód přispěvatele
    ČGS (RIV)
Zdrojový formát
Datum importu
    15. 10. 2014