# Bristol's Simon Lock models how a fast-spinning early Earth formed the first continental crust

- Published: 2026-11-15 17:43 UTC
- Section: Planet › Earth sciences
- Tags: formation of continents, early Earth rotation, Moon-forming impact, Simon Lock, JGR: Solid Earth, primary crust, granitoid rocks, plate tectonics, carbon cycle, Venus and Earth
- URL: https://realtech.media/news/rt-b11a1028e40260d2703abbc8_bristol_s_simon/

**A study in JGR: Solid Earth proposes that the slowing of Earth's spin after the Moon-forming impact cracked the early crust. The hypothesis remains theoretical.**

![Bristol's Simon Lock models how a fast-spinning early Earth formed the first continental crust](https://realtech.media/media/2026/11/5db801e730e3c2b3.jpg)
*pravda.ru*

About 4.5 billion years ago, the early Earth was struck by a Mars-sized body, according to pravda.ru's account of a study by planetologist Simon Lock of the University of Bristol, published in JGR: Solid Earth. The collision formed the Moon and set Earth spinning so fast that a day lasted only a few hours [1]. Lock proposes that this rapid rotation drove the formation of the first continents and the start of geological processes [1].

## Spin, bulge and crust stress

Because of the fast rotation, the young Earth was strongly flattened at the poles and had a pronounced bulge at the equator [1]. As the Moon gradually moved away, the planet's rotation slowed and the equatorial bulge shrank. The crust, which had already begun to cool, was under enormous stress [1].

According to Lock's calculations, equatorial regions were compressed with a force comparable to the one that builds mountain ranges such as the Himalayas today. Such deformation cracked the dense primary crust. Water and carbon dioxide penetrated into the interior, causing active volcanism and melting of rocks. In this way, the scientists believe, the first light granitoid-like rocks appeared, which became the basis of future continents [1].

Geologists had long been unable to explain why elements of continental crust appeared so early, within the first 200 million years of Earth's history. Existing models assume that this requires plate tectonics. Lock's scenario shows that the planet could have reworked its interior without that mechanism [1].

## Implications for early Earth

Manar Al-Asad, a geophysicist at Dartmouth College, notes that the work opens new prospects for understanding the early Earth, including the interaction of its core and mantle. There is also a suggestion that fragments of the dense primary crust sank deep into the planet and formed the dense zones at the core-mantle boundary that still exist [1].

The study also touches on why Earth became habitable while its "sister" Venus became a lifeless planet with an extremely hot climate. The scientists suggest that tectonic activity triggered by the Moon's tidal influence and the slowing of rotation played a key role in regulating the carbon cycle [1].

Planetologist Yoshinori Miyazaki of Rutgers University says Lock's model looks quite logical and fits the overall picture, explaining Earth's unique geological evolution [1]. For now the hypothesis remains theoretical, since too few rocks from that period have survived [1].

## Sources

1. [pravda.ru](https://www.pravda.ru/news/science/2443232-early-earth-geology-evolution)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-b11a1028e40260d2703abbc8_bristol_s_simon/