美国伍兹霍尔海洋研究所R. L. Tyne团队研究了浅层年轻地下水中岩石圈挥发物的被动脱气。该项研究成果发表在2025年6月5日出版的《自然—地球科学》杂志上。
地球上生命的发展得益于其富含挥发性的表面。地球表面的波动预算受进气（例如，通过俯冲）和排气（例如，经过岩浆和构造过程）之间的平衡控制。尽管与CI球粒陨石相比，地球内部的挥发物相对较少，但由于其巨大的体积，地球内部挥发物的总量仍然很大。然而，与火山活动没有直接关系的地球内部弥漫脱气的相对程度并没有得到很好的限制。
研究组使用了溶解的氦和高精度的氩同位素，以及哥伦比亚高原地区含水层（美国华盛顿和爱达荷州）地下水中溶解的无机碳的放射性碳。他们确定了地幔和地壳的挥发性来源，并量化了它们向地表的通量。地下水中过量的氦和氩表明是次大陆岩石圈地幔和地壳源的混合，这表明次大陆岩石圈地幔的被动脱气可能是一个重要但以前未被认识的脱气过程。这一发现对于量化长期全球挥发性物质平衡至关重要，即使在地壳火山活动静止的部分也可能发生大量放气。
附：英文原文
Title: Passive degassing of lithospheric volatiles recorded in shallow young groundwater
Author: Tyne, R. L., Broadley, M. W., Bekaert, D. V., Barry, P. H., Warr, O., Langman, J. B., Musan, I., Jenkins, W. J., Seltzer, A. M.
Issue&Volume: 2025-06-05
Abstract: The development of life on Earth has been enabled by its volatile-rich surface. The volatile budget of Earth’s surface is controlled by the balance between ingassing (for example, via subduction) and outgassing (for example, through magmatic and tectonic processes). Although volatiles within Earth’s interior are relatively depleted compared to CI chondrites, the total amount of volatiles within Earth is still substantial due to its vast size. However, the relative extent of diffuse degassing from Earth’s interior, not directly related to volcanism, is not well constrained. Here we use dissolved helium and high-precision argon isotopes combined with radiocarbon of dissolved inorganic carbon in groundwater from the Columbia Plateau Regional Aquifer (Washington and Idaho, USA). We identify mantle and crustal volatile sources and quantify their fluxes to the surface. Excess helium and argon in the groundwater indicate a mixture of sub-continental lithospheric mantle and crustal sources, suggesting that passive degassing of the sub-continental lithospheric mantle may be an important, yet previously unrecognized, outgassing process. This finding that considerable outgassing may occur even in volcanically quiescent parts of the crust is essential for quantifying the long-term global volatile mass balance.
DOI: 10.1038/s41561-025-01702-7
Source: https://www.nature.com/articles/s41561-025-01702-7