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| Peate, Dw; Baker, Ja; Blichert-toft, J; Hilton, Dr; Storey, M; Kent, Ajr; Brooks, Ck; Hansen', H; Pedersen, Ak; Duncan, Ra. |
| We present elemental and isotopic (Sr-Nd-Pb-Hf-Os-He) data on primitive alkalic lavas from the Prinsen af Wales Bjeige, East Greenland. Stratigraphical, compositional and Ar-40-Ar-39 data indicate that this inland alkalic activity was contemporaneous with the upper parts of the main tholeiitic plateau basalts and also postdated them. The alkalic rocks show a marked crustal influence, indicating establishment of new magmatic plumbing systems distinct from the long-lived coastal systems that fed the relatively uncontaminated plateau basalts. The least contaminated lavas have high He-3/He-4 isotope ratios (R/R-A 12.4-18.5), sub-chondritic Os-187/(OSi)-O-88 (0.120-0.126), low epsilonNd(i) (similar to + 4) and epsilonHf(i) (similar to+ 6) that plot below the... |
| Tipo: Text |
Palavras-chave: Alkalic lavas; Flood basalts; High He-3/He-4; East Greenland; Recycled lithosphere; Iceland plume. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00224/33507/31953.pdf |
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