Highest terrestrial 3He/4He credibly from the core
Highest terrestrial 3He/4He credibly from the core
复制标题
地核中最高的 3He/4He
DOI：
10.1038/s41586-023-06590-8
复制
发表时间：
2023
期刊：
影响因子：
64.8
通讯作者：
Boyes, X. M.
中科院分区：
文献类型：
--
作者：
Horton, F.;Asimow, P. D.;Farley, K. A.;Curtice, J.;Kurz, M. D.;Blusztajn, J.;Biasi, J. A.;Boyes, X. M.
许多与地幔柱有关的熔岩比上对流地幔具有更高的3 He/4 He比值，这一观测结果支持了地球深部的地球物理、地球动力学和地球化学模型。高的3 He/4 He比率被认为来自太阳星云或太阳风辐射的物质，这些物质在早期的行星吸积过程中被并入地球。传统上，这种高3 He/4 He组分被认为是地幔固有的，避免了巨大撞击和数十亿年地幔对流造成的释气。在这里，我们报告了最高的岩浆3 He/4 He比（67.2 ± 1.8倍的大气比），但在陆地火成岩，从巴芬岛熔岩橄榄石测量。我们认为，这些熔岩中极高的3 He/4 He氦可能来自地核。核心假说的可行性放松了长期存在的限制基于全球范围内与地幔柱相关的熔岩中的惰性气体来自太阳星云的挥发性元素自吸积早期就在地幔中存活下来。
The observation that many lavas associated with mantle plumes have higher3He/4He ratios than the upper convecting mantle underpins geophysical, geodynamic and geochemical models of Earth’s deep interior. High3He/4He ratios are thought to derive from the solar nebula or from solar-wind-irradiated material that became incorporated into Earth during early planetary accretion. Traditionally, this high-3He/4He component has been considered intrinsic to the mantle, having avoided outgassing caused by giant impacts and billions of years of mantle convection, , –. Here we report the highest magmatic3He/4He ratio(67.2 ± 1.8 times the atmospheric ratio) yet measured in terrestrial igneous rocks, in olivines from Baffin Island lavas. We argue that the extremely high-3He/4He helium in these lavas might derive from Earth’s core, , , –. The viability of the core hypothesis relaxes the long-standing constraint—based on noble gases in lavas associated with mantle plumes globally—that volatile elements from the solar nebula have survived in the mantle since the early stages of accretion.