Given the scarcity of geological data, knowledge of Earth’s landscape during the Archaean eon is limited. Although the continental crust may have been as massive as present by 4 Gyr ago, the extent to which it was submerged or exposed is unclear. One key component in understanding the amount of exposed landmasses in the early Earth is the evolution of the oceanic lithosphere. Whereas the present-day oceanic lithosphere subsides as it ages, based on numerical models of mantle convection we find that higher internal heating due to a larger concentration of radioactive isotopes in the Archaean mantle halted subsidence, possibly inducing seafloor shallowing before 2.5 Gyr ago. In such a scenario, exposed landmasses in the form of volcanic islands and resurfaced seamounts or oceanic plateaus can remain subaerial for extended periods of time, and may have provided the only stable patches of dryland in the Archaean. Our results therefore permit a re-evaluation of possible locations for the origin of life, as they provide support to an existing hypothesis that suggests that life had its origins on land rather than in an oceanic environment.

鉴于地质数据的稀缺，对太古宙期间地球景观的了解是有限的。尽管大陆地壳可能与 4 Gyr 以前一样大，但它被淹没或暴露的程度尚不清楚。了解早期地球裸露陆地数量的一个关键组成部分是海洋岩石圈的演化。尽管当今的海洋岩石圈随着年龄的增长而消退，但基于地幔对流的数值模型，我们发现由于太古宙地幔中放射性同位素浓度较高而导致的较高内部加热停止了下沉，可能在 2.5 Gyr 之前引起海底变浅。在这种情况下，以火山岛和重新浮出水面的海山或海洋高原形式的裸露陆地可以在很长一段时间内保持在空中，并且可能提供了太古代唯一稳定的旱地。因此，我们的结果允许重新评估生命起源的可能位置，因为它们为现有假设提供了支持，该假设表明生命起源于陆地而不是海洋环境。