Typical oxygen isotope profile of altered oceanic crust recorded in continental intraplate basalts - Université de Lille Accéder directement au contenu
Article Dans Une Revue Journal of Earth Science Année : 2017

Typical oxygen isotope profile of altered oceanic crust recorded in continental intraplate basalts

Résumé

Recycled oceanic crust (ROC) has long been suggested to be a candidate introducing enriched geochemical signatures into the mantle source of intraplate basalts. The different parts of oceanic crust are characterized by variable oxygen isotope compositions (δ18O=3.7‰ to 13.6‰). To trace the signatures of ROC in the mantle source of intraplate basalts, we measured the δ18O values of clinopyroxene (cpx) phenocrysts in the Cenozoic basalts from the Shuangliao volcanic field, NE China using secondary ion mass spectrometer (SIMS). The δ18O values of the Shuangliao cpx phenocrysts in four basalts ranging from 4.10‰ to 6.73‰ (with average values 5.93‰±0.36‰, 5.95‰±0.30‰, 5.58‰±0.66‰, and 4.55‰± 0.38‰, respectively) apparently exceed those of normal mantle-derived cpx (5.6‰±0.2‰) and fall in the typical oxygen isotope range of altered oceanic crust. The δ18O values display the negative correlations with the Eu, Sr anomalies of whole rocks and erupted ages, demonstrating that (1) the ROC is the main enriched component in the mantle source of the Shuangliao basalts and (2) the contributions of ROC varied with time. The basalt with the lowest δ18O value is characterized by a significant K positive anomaly, highest H2O/Ce and Ba/Th ratios, suggesting that the mantle source of basalts with low δ18O can also include a water-rich sediment component that may be the trigger for partial melting. Considering the continuous subduction of the Pacific slab, the temporal heterogeneity of the source components is likely to be caused by the Pacific slab subduction.
Fichier non déposé

Dates et versions

hal-04642949 , version 1 (10-07-2024)

Identifiants

Citer

Huan Chen, Qun-Ke Xia, Etienne Deloule, Jannick Ingrin. Typical oxygen isotope profile of altered oceanic crust recorded in continental intraplate basalts. Journal of Earth Science, 2017, Journal of Earth Science, 28, pp.578-587. ⟨10.1007/s12583-017-0798-5⟩. ⟨hal-04642949⟩
0 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Mastodon Facebook X LinkedIn More