A chemical fingerprint in ancient rocks suggests plate tectonics began 2.5 billion years ago
Tectonic plates may have allowed life to form on Earth – but exactly when they started moving is a long-standing mystery.
Plate tectonics, a process responsible for shaping Earth's surface and maintaining conditions conducive to life, has long puzzled scientists regarding its onset. A recent study analyzing ancient rocks from various continents, including Australia, Africa, North America, and Europe, has provided a compelling answer. This research found definitive evidence of plate tectonics beginning approximately 2.5 billion years ago, a crucial turning point in Earth's history.
According to the study, rocks older than 2.5 billion years contain a distinct chemical signature indicative of ancient crust formed around four billion years ago. This ancient crust persisted for over a billion years before disappearing abruptly around 2.5 billion years ago. The disappearance of this signature in later rocks suggests a significant shift in Earth's geological processes.
The findings imply that the emergence of plate tectonics around 2.5 billion years ago marked a pivotal moment in Earth's history. This period likely transitioned Earth from a "habitable" to a "non-habitable" state, setting the stage for the development of life as we know it. The study, conducted by analyzing over 1,200 rocks, provides compelling evidence of this critical geological event, shedding light on the long-standing mystery of when plate tectonics first began.
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