Only 800 million years after the formation of the earth, the first land masses already loomed.

We know that the Earth was formed about 4.5 billion years ago. Between 4.4 and 4.2 billion years ago, the first oceans appeared, covering the entire Earth’s crust. But when did the first land rise above sea level? Dutch researchers are now lifting a corner of the veil.

First Landmasses

In the new study, published in Nature Geoscience, geologists examined the appearance of the first significant land masses. And that leads to a surprising conclusion. For example, it seems that the first country on Earth appeared about 3.7 billion years ago. That is a billion years earlier than thought. Moreover, this means that the first country appeared only 800 million years after the creation of the earth.


The researchers rely on analyzes of ancient rocks. “We can’t look back in time to the first country,” explains researcher Paul Mason. “But we can find traces of it that are stored in old rocks. We examined minerals that precipitated from seawater and stored, as it were, the information about those first pieces of exposed land.”


Scientists suspect that the very first mountain ranges on Earth may have consisted mainly of the granite rock. Granite has a relatively low density, which easily rises above other rocks on the seabed. The researchers therefore elaborated on this. Granite is rich in the element rubidium, which can make a new isotope of the element strontium via radioactive decay. “We can then see from the ratio of strontium isotopes in seawater whether it comes from exposed granite rocks,” explains research leader Desiree Roerdink. “In other words, from land above sea level.”

However, the composition of the seawater from the past can no longer be traced. Therefore, in their study, the researchers used an indirect way to analyze seawater from billions of years ago. They studied the mineral barite, which forms on the sea floor. Barite captures the strontium from the seawater and thus contains a fingerprint of the isotopes that originally washed out of those first land masses.

The research leads to the striking discovery that the first land on earth arose much earlier than thought. The minerals under investigation, which were found in present-day South Africa, India and Australia, have subsequently been preserved unaltered for 3.5 billion years.

Oldest traces of land

Mason does have an important caveat, however. “Note that we are talking about the oldest traces of land that have been recovered here,” he nuances. “That doesn’t mean there wasn’t land above sea level before. There may have been islands in the oceans longer than 3.7 billion years ago, but they were simply too small to leave traces after they eroded and disappeared.”


In addition, the findings also do not imply that present-day South Africa, India and Australia are the oldest landmasses. “Only that those areas harbor the traces of those old rocks,” says Roerdink. “The Earth’s crust is constantly changing. Continents shift, disappear or arise. And a piece of rock that you now find somewhere may have formed on the other side of the earth.”

In addition to re-dating the first country on our planet, the study also provides crucial information about the origin of life, Roerdink emphasizes. “The erosion of rocks supplied the oceans with essential nutrients, such as phosphorus,” she says. “The geological and biological evolution on the early Earth were thus closely linked.”