It turns out that rock salt harbors 830 million-year-old microorganisms (which may still be alive!)

It may have been bacteria or algae that got trapped in the minerals hundreds of millions of years ago.

It can be read in the magazine geology† The study is about rock salt, which originated about 830 million years ago and is found in the Brown Formation in central Australia. “Mineral rock salt is formed when there are an abundance of sodium and chloride ions in solution,” explains researcher Sarah Schrader-Gomez. Scientias. nl from. “When there are a lot of ions in the solution and the saturation point is reached, solid minerals are formed.” Those minerals have a crystalline structure. Which means they are made up of a regular pattern of particles: in this case sodium and chloride ions. “However, when rock salt crystals grow rapidly, defects can form in those crystals and some water can become trapped in the crystal structure.” Some of these trapped fluids also contain solids, such as microorganisms that lived in the water near where the rock salt crystals formed.”

Bacteria or algae
And that’s exactly what researchers found in rock salt recovered in Australia. “Based on their size, shape, and color, we can classify microorganisms as prokaryotes (bacteria and/or archaea) or eukaryotes (possibly algae or fungi),” Schrader Gomez said.

noticeable
It’s a wonderful discovery. “We weren’t much surprised to find microorganisms in rock salt from the Brown Formation,” the researcher said. “But we were very excited about it. Previous studies have already found microorganisms in modern rock salt and in ancient rock salt, up to 250 million years old. It is remarkable that we were able to find microorganisms in such ancient minerals and that they were so well preserved. !”

Because the microorganisms must have been trapped in the rock salt when it formed, it was certainly as old as the minerals themselves. The researchers wrote that these minerals originated 830 million years ago.

extremists
It is not possible to be certain of the type of microorganisms involved. It can be bacteria, but also algae or fungi. However, based on the environment in which the unfortunate microorganisms lived millions of years ago, researchers believe they can say more about the nature of the microorganisms. For example, we have to keep in mind that crystals in which microorganisms are trapped are formed in very salty water. Thus it is quite possible to classify the microorganisms now present in the crystals as microorganisms. These are organisms that live in harsh conditions. This is not certain; For example, microbes could also have been deposited in the highly saline water by the wind. In this case, they are not extreme microorganisms, but “normal” microorganisms that have ended up in a harsh environment.

sympathy?
However it turns out, one thing is certain: microorganisms have not been able to escape the crystal structure and are still trapped in it – 830 million years later. Sounds like a tragic story. But it’s not yet certain that the microorganisms that were spotted also died in solitary confinement, says Schrader Gomez. “It is possible—but not likely—that these organisms are still alive. Some of the salt-loving (salt-loving) organisms that we know today have survival mechanisms that enable them to survive even at times when conditions are not favorable (on (e.g., when available nutrients are limited). For example, they put their metabolism on the back burner. We don’t yet fully understand how microorganisms – particularly microorganisms in highly saline environments – can survive for so long. In previous studies, researchers sometimes extracted bacteria from rock salt up to 250 million years old and then placed them on a farm. Future research could similarly examine life in the Brown Formation.”

Pending a follow-up study, it remains a mystery whether the microorganisms survived millions of years of captivity. But even if they all died, it would still be a curious discovery. Because what this teaches us is that the microorganisms in rock salt can be well preserved and recognizable for hundreds of millions of years in a row. This provides opportunities. For example, in the search for extraterrestrial life on Mars. The planet today is dry, cold, and unattractive to life as we know it, but that may have been different in the past; There is plenty of evidence that the planet was wet and warm. If Mars at that time also harbored microbial life (perhaps now extinct), minerals might be a good place to look for them. “Mars is home to a range of minerals and rock formations very similar to what we see in the Brown Formation,” Schrader Gomez explains. Sometimes these minerals are incomplete and contain water. And if that water in turn contained microorganisms, they could still be identified in that crystal structure. “Potential bio-fingerprints can be stored in this way and can be detected if we can study the waters trapped here on Earth.” So the implications of Schraeder-Gomes and colleagues’ work could extend far beyond Earth. Schrader Gomez asserts that “the age of the rocks (which has been studied for the research) is also important.” “Because it shows that traces of life here on Earth – and thus hopefully also on Mars – can still be detected hundreds of millions of years later.”