Molecular hydrogen production occurs through the serpentinization of mantle peridotite exhumed at mid‐ocean ridges. Hydrogen is considered essential to sustain microbial life in the subsurface; however, estimates of hydrogen flux through geological time are unknown. Here we present a model of the primary, abiotic production of molecular hydrogen from the serpentinization of oceanic lithosphere using full‐plate tectonic reconstructions for the last 200 Ma. We find significant variability in hydrogen fluxes (1–70 • 10¹⁶ mol/Ma or 0.2–14.1 • 10⁵ Mt/a), which are a function of the sensitivity of evolving ocean basins to spreading rates and can be correlated with the opening of key ocean basins during the breakup of Pangea. We suggest that the primary driver of this hydrogen flux is the continental reconfiguration during Pangea breakup, as this produces ocean basins more conducive to exhuming and exposing mantle peridotite at slow and ultraslow spreading ridges. Consequently, present‐day flux estimates are ~7 • 10¹⁷ mol/Ma (1.4 • 10⁶ Mt/a), driven primarily by the slow and ultraslow spreading ridges in the Atlantic, Indian, and Arctic oceans. As methane has also been sampled alongside hydrogen at hydrothermal vents, we estimate the methane flux using methane‐to‐hydrogen ratios from present‐day hydrothermal vent fluids. These ratios suggest that methane flux ranges between 10 and 100% of the total hydrogen flux, although as the release of methane from these systems is still poorly understood, we suggest a lower estimate, equivalent to around 7–12 • 10¹⁶ mol/Ma (1.1–1.9 • 10⁷ Mt/Ma) of methane.

中文翻译：

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Pangea破裂带动的中洋海脊脉动的全球氢气和甲烷通量

氢气的产生是通过在中海脊发掘出的地幔橄榄岩蛇纹石化产生的。氢被认为对维持地下微生物的生存至关重要。但是，尚不清楚通过地质时间的氢通量的估算。在这里，我们提供了一个模型，该模型使用前200 Ma的全板构造重建从海洋岩石圈的蛇形化过程中产生了主要的非生物分子氢。我们发现氢通量存在显着变化（1–70•10 ¹⁶  mol / Ma或0.2–14.1•10 ⁵ Mt / a），这是不断演变的海盆对扩散速率的敏感性的函数，并且可以与Pangea破裂期间主要海盆的开放相关。我们认为，这种氢通量的主要驱动力是Pangea破裂期间的大陆重组，因为这会使海盆更有利于在慢速和超慢扩散脊上挖掘和暴露地幔橄榄岩。因此，目前的通量估计值为〜7•10 ¹⁷  mol / Ma（1.4•10 ⁶Mt / a），主要是由大西洋，印度洋和北冰洋的缓慢和超慢扩张脊所驱动。由于在热液喷口处还与甲烷一起对甲烷进行了采样，因此我们使用当今热液喷口液中甲烷与氢的比率估算了甲烷通量。这些比率表明甲烷通量在总氢通量的10％到100％之间，尽管由于人们对这些系统中甲烷的释放仍知之甚少，我们建议采用较低的估算值，大约为7–12•10 ¹⁶  mol / Ma （1.1–1.9•10 ⁷  Mt / Ma）的甲烷。