Abnormal lithium isotope composition from the ancient lithospheric mantle beneath the North China Craton

Abstract : Lithium elemental and isotopic compositions of olivines in peridotite xenoliths from Hebi in the North China Craton provide direct evidence for the highly variable δ7Li in Archean lithospheric mantle. The δ7Li in the cores of olivines from the Hebi high-Mg# peridotites (Fo > 91) show extreme variation from −27 to +21, in marked deviation from the δ7Li range of fresh MORB (+1.6 to +5.6) although the Li abundances of the olivines are within the range of normal mantle (1–2 ppm). The Li abundances and δ7Li characteristics of the Hebi olivines could not have been produced by recent diffusive-driven isotopic fractionation of Li and therefore the δ7Li in the cores of these olivines record the isotopic signature of the subcontinental lithospheric mantle. Our data demonstrate that abnormal δ7Li may be preserved in the ancient lithospheric mantle as observed in our study from the central North China Craton, which suggest that the subcontinental lithospheric mantle has experienced modification of fluid/melt derived from recycled oceanic crust.
Document type :
Journal articles
Complete list of metadatas

https://hal.univ-lorraine.fr/hal-01765187
Contributor : Crpg Ul <>
Submitted on : Thursday, April 12, 2018 - 4:10:13 PM
Last modification on : Wednesday, August 14, 2019 - 8:32:01 PM

Links full text

Identifiers

Collections

Citation

Yan Tang, Hong-Fu Zhang, Etienne Deloule, Ben-Xun Su, Ji-Feng Ying, et al.. Abnormal lithium isotope composition from the ancient lithospheric mantle beneath the North China Craton. Scientific Reports, Nature Publishing Group, 2015, 4 (1), ⟨10.1038/srep04274⟩. ⟨hal-01765187⟩

Share

Metrics

Record views

46