当前位置: X-MOL 学术Geochim. Cosmochim. Acta › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Molybdenum isotopic constraints on the origin of EM1-type continental intraplate basalts
Geochimica et Cosmochimica Acta ( IF 4.5 ) Pub Date : 2021-11-16 , DOI: 10.1016/j.gca.2021.11.013
Liang Ma 1, 2, 3 , Yi-Gang Xu 1, 2, 3 , Jie Li 1, 2, 3 , Li-Hui Chen 4 , Jian-Qiang Liu 5 , Hong-Yan Li 1, 2, 3 , Xiao-Long Huang 1, 2, 3 , Qiang Ma 1 , Lu-Bing Hong 1 , Yu Wang 1, 2, 3
Affiliation  

The origin of enriched mantle 1 (EM1) component in the mantle has long been debated. EM1 source of basalts has been variously attributed to recycled sub-continental lithosphere, recycled lower continental crust, or recycled oceanic crust plus pelagic sediments. Molybdenum stable isotope systematics has the potential to resolve this debate, because of the significant isotopic differences between mantle and crustal reservoirs. Here we present molybdenum isotope data for EM1-type continental intraplate basalts from Nuominhe (NMH), Northeast China. The NMH basalts display significant variations in both δMo (Mo/Mo ratio relative to NIST SRM 3134, −0.49 to −0.15‰) and Mo/Ce (0.009–0.037), and strong correlations between δMo, Mo/Ce and Hf isotope and trace elements. EM1 end-member of the NMH basalts shows the lightest δMo and lowest Mo/Ce values. The involvement of continental crust and sub-continental lithospheric mantle cannot account for the light Mo isotopic compositions of the basalts. By contrast, the recycled oceanic crust with pelagic sediments, characterized by low δMo and Mo/Ce values, is the satisfactory candidate for the EM1 component in the NMH basalts. Our results also suggest a residual slab reservoir with light δMo values (<−0.5‰) in the mantle beneath Northeast China, representing the complementary reservoir to heavy Mo isotope continental crust. Identification of this reservoir makes the Mo isotope system a powerful tracer of crust-mantle interactions.
更新日期:2021-11-16
down
wechat
bug