An examination of some of oldest rocks on the planet suggests that the first continents were unstable and then sank back into Earth’s mantle, before resurfacing and reforming.
This could explain some of their more bizarre characteristics, particularly the extremely old and stable areas of the The lithosphere(the crust and the uppermost mantle) which have survived continental changes over many eons. They also record Earth’s ancient history.
TThese new findings could aid in understanding Earth’s changing geology over its estimated 4.5 billion-year-long lifespan.
“The rocks at the cores of the continents, known as cratons are more than three trillion years old,” explainsFabio Capitanio, a geologist at Monash University School of Earth, Atmosphere and Environment, Australia.
They formed in the early Earth. They hold the secret of how continents and the planet have changed over time.
We don’t know the exact process of how continents were formed. No other planet is in the Solar System Has anyone done anything similar to them?So it is evident that there must exist a set of specific circumstances.
Multiple evidences suggest that the continents could have been formed from the interior, out, or around. cratonic Cores. However, the formation mechanism for the cratons itself is hotly debated.
Cratons, which are found all around 35 are known at the momentThey are more stable than other parts of the Lithosphere because they are rigid and buoyant. Their composition is different from the more recent lithosphere. It contains a bizarrely varied mix of minerals, including minerals with a variety of ages, compositions and sources.
This diversity or heterogeneity is called heterogeneity. It is an indication of recycling and/or reworking Previous research has shown that.
Capitanio and his colleagues used computational modeling to model the evolution of Earth over the first billion years of its existence. They also observed the chemical and thermal evolution of the cratonic mantle. To test the model’s sensitivity to different parameters, they also ran several simulations.
These results revealed that the first continent blocks to appear on Earth were instabile and were able to sink back into the mantle. These blocks melted and were mixed with the molten material, until they became dissolved.
Some pieces, however, can remain there for a very long time before floating up. They build up underneath the lithosphere, giving it buoyancy, rigidity, and layers.
Some older pieces of rock may remain in the mantle for a long time. This can explain why there is heterogeneity in the cratonic structure: older rocks from different locations mixed with younger rocks.
It is possible that some pieces could still be down there, just waiting to float up again.
This mechanism was dubbed’massive region relamination’ by the team (MRR). Its apparent alignment with the observed composition of the cratons suggests that it could have been an important component of early Earth’s continent formation.
Understanding the formation of continents is crucial to the existence and survival of life on Earth. This knowledge will also be useful for searching for planets that are habitable outside our Solar System.
Capitanio: “Our work is valuable in two ways.” Says.
“First, cratons store/found important metals. They also tell us about the history of planets, such as how they formed and changed over time, how they supported life, how they formed, and how the atmosphere changed and formed due to tectonics.
The research was published in PNAS.
