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 history of Earth is written on the great tablets of tectonic plates. The motions of plates shaped land masses, formed oceans, and created the varied climates and habitats that set the stage for evolution and the diversity ...
Earth Sciences
Mar 19, 2026
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Scientists have long sought to explain a key mismatch in Earth's early history: oxygen-producing photosynthesis evolved hundreds of millions of years before atmospheric oxygen began to rise during the Great Oxidation Event. ...
Earth Sciences
Mar 19, 2026
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The rocks beneath our feet are leaving a hidden signature in the shells of marine snails along Australia's ancient coastline, according to new research led by Adelaide University scientists. A study published in Proceedings ...
Ecology
Mar 18, 2026
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Western Australian hydrothermal and magmatic deposits that formed several hundred kilometers apart more than two and half billion years ago share more commonalities than previously thought.
Earth Sciences
Feb 19, 2026
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Oxygen is a vital and constant presence on Earth today. But that hasn't always been the case. It wasn't until around 2.3 billion years ago that oxygen became a permanent fixture in the atmosphere, during a pivotal period ...
Evolution
Feb 6, 2026
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More than 3.5 billion years ago, the Earth was not the hospitable world we know today. The atmosphere lacked oxygen, the seas were acidic and rich in iron, and volcanic activity roared across a barren landscape. Yet, in this ...
Evolution
Jan 23, 2026
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By resurrecting a 3.2-billion-year-old enzyme and studying it inside living microbes, researchers at the University of Wisconsin–Madison have created a new way to improve our understanding of the origins of life on Earth ...
Astrobiology
Jan 22, 2026
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You have probably seen the images of the surface of Mars, beamed back by NASA's rovers. What if there were a time machine capable of roaming Earth during its remote geological past, perhaps even going right back to its beginnings, ...
Earth Sciences
Jan 2, 2026
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For roughly 2 billion years of Earth's early history, the atmosphere contained no oxygen, the essential ingredient required for complex life. Oxygen began building up during the period known as the Great Oxidation Event (GOE), ...
Astrobiology
Dec 9, 2025
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A new study uncovered fresh chemical evidence of life in rocks more than 3.3 billion years old, along with molecular traces showing that oxygen-producing photosynthesis emerged nearly a billion years earlier than previously ...
Astrobiology
Nov 17, 2025
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