Earth’s rocky crust has been its feature for billions of years; however, only a small fraction of it dates back that far. To determine the crust’s age, researchers have studied the decay of ancient chemicals trapped in rocks. They examine the carbonate materials extracted from oceans. But these minerals are hard to find and are rarely in a condition to be examined.
Now, a team of researchers has found a new way to date ancient pieces of the Earth’s crust. As per their latest research, previous studies misjudged the age of the continents by half a billion years.
Earth’s crust is 3.7 billion years old
In the research, the team showed that by examining barite mineral. It is a blend of ocean salts and barium released by volcanic ocean vents. The researchers found evidence that Earth’s continental crust was around at least 3.7 billion years ago, way older than estimated earlier.
“It has implications for the way that we think about how life evolved,” said the study’s lead author Desiree Roerdink. “The composition of a piece of barite … that has been on Earth for three and a half billion years is exactly the same as it was when it actually precipitated. It is a great recorder to look at processes on the early Earth,” he added.
The main process here is weathering. With time, continents wear down, spilling nutrients into the closest sea. These nutrients foster life in the seas, as per a study. The researchers also found that during Earth’s “middle age,” the evolution of life suddenly slowed down.
Half a billion years older than estimated
Continental crust also leaks strontium into the ocean. By calculating the ratio of two strontium isotopes in six different barite minerals, the team managed to calculate the age of these minerals, ranging from 3.2 billion to 3.5 billion years old. Researchers concluded that continental weathering started 3.7 billion years ago.
This also suggests that continents were well-established 3.7 billion years ago, which is around half a billion years earlier than previous estimates.
Astronomers have been unraveling many mysteries about our planet lately. Recently, a team of scientists found that in the last 25 years, Earth’s north and south poles have drifted about 13 feet. As per the study, Earth’s axis started shifting drastically in 1995, the main reason behind the shift is found to be melting glaciers.
