Identification of chondritic krypton and xenon in Yellowstone gases and the timing of terrestrial volatile accretion

Abstract

Identifying the origin of noble gases in Earth’s mantle can provide crucial constraints on the source and timing of volatile (C, N, H2O, noble gases, etc.) delivery to Earth. It remains unclear whether the early Earth was able to directly capture and retain volatiles throughout accretion or whether it accreted anhydrously and subsequently acquired volatiles through later additions of chondritic material. Here, we report high-precision noble gas isotopic data from volcanic gases emanating from, in and around, the Yellowstone caldera (Wyoming, United States). We show that the He and Ne isotopic and elemental signatures of the Yellowstone gas requires an input from an undegassed mantle plume. Coupled with the distinct ratio of129Xe to primordial Xe isotopes in Yellowstone compared with mid-ocean ridge basalt (MORB) samples, this confirms that the deep plume and shallow MORB mantles have remained distinct from one another for the majority of Earth’s history. Krypton and xenon isotopes in the Yellowstone mantle plume are found to be chondritic in origin, similar to the MORB source mantle. This is in contrast with the origin of neon in the mantle, which exhibits an isotopic dichotomy between solar plume and chondritic MORB mantle sources. The co-occurrence of solar and chondritic noble gases in the deep mantle is thought to reflect the heterogeneous nature of Earth’s volatile accretion during the lifetime of the protosolar nebula. It notably implies that the Earth was able to retain its chondritic volatiles since its earliest stages of accretion, and not only through late additions.

The Systematics of Chlorine, Lithium, and Boron andδ37Cl,δ7Li, and δ11B in the Hydrothermal System of the Yellowstone Plateau Volcanic Field

“…The emission rate and isotopic composition suggest that a significant amount of helium has been liberated from the Archean rocks over the past 2 million years since the crust was affected by magmatism (Lowenstern, Evans, et al., 2014). Other studies have shown some of the other noble gases and nitrogen emitted from the YPVF hydrothermal system are derived from the mantle (Broadley et al., 2020; Labidi et al., 2020).…”

“…nitrogen emitted from the YPVF hydrothermal system are derived from the mantle (Broadley et al, 2020;Labidi et al, 2020).…”

Spatial Characteristics of Recycled and Primordial Reservoirs in the Deep Mantle

“…Similarly, a value of 24.2 ± 2.8 Ra was reported by crushing olivine separates associated with glacial moraines near Yellowstone (Licciardi et al., 2001), but higher 3 He/ 4 He (92.6 Ra) was obtained by fusion of the crushed olivines, and more work is needed to exclude a cosmogenic 3 He component in the crushing experiment. Nonetheless, it is clear that a primordial component exists in the Yellowstone plume (e.g., Broadley et al., 2020; Labidi et al., 2020), and a deep plume source for Yellowstone (Nelson & Grand, 2018; Steinberger et al., 2019) is evidence that elevated 3 He/ 4 He exists outside of the LLSVPs in the deep mantle.…”

In situ produced cosmogenic krypton in zircon and its potential for Earth surface applications

“…Bromine concentrations are low in silicate minerals (Kendrick, 2012;Ruzie-Hamilton et al, 2016;Teiber et al, 2015) (Buizert et al, 2014;Aregbe et al, 1996)). Natural krypton is rarely measured in geological material due to the anticipated consistency of these values (Broadley et al, 2020;Trieloff et al, 2000).…”