The Archaean is a geologic eon of Earth history spanning approximately 4.0 to 2.5 billion years ago, following the Hadean and preceding the Proterozoic. It is characterized by high heat flow, a largely anoxic atmosphere, and the stabilization of the first substantial continental crust, dominated by granite–greenstone terranes and high-grade gneiss complexes. Plate tectonic processes were likely more vigorous due to higher mantle temperatures, influencing crustal growth and metamorphism. The Archaean also encompasses the earliest widely accepted evidence of life, primarily prokaryotic microorganisms, preserved in stromatolites and microfossils, which played a foundational role in shaping subsequent biospheric and geochemical evolution.
The early Earth was an extreme place. Asteroids pommeled the surface. Volcanoes spewed lava and carbon dioxide. The thick, toxic atmosphere lacked oxygen. Yet, in this turmoil, life emerged.
Astrobiology
Jan 8, 2025
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The key to unlocking the secrets of distant planets starts right here on Earth. Researchers at Tohoku University, the University of Tokyo, and Hokkaido University have developed a model that considers various atmospheric ...
Astrobiology
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Billions of years ago, long before anything resembling life as we know it existed, meteorites frequently pummeled the planet. One such space rock crashed down about 3.26 billion years ago, and even today, it's revealing secrets ...
Astrobiology
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