Microorganisms 830 million years old have been discovered in Australia

Researchers at West Virginia University have been able to identify tiny remnants of prokaryotic and eukaryotic life trapped in 830 million-year-old halite crystals.

Microbial life trapped hundreds of millions of years

described in the review geologyThis important discovery involved the use of petrography Using transmitted light and ultraviolet rays to examine the crystalshalite (or rock salt) from the depths of the formation Neoproterozoic from Brownat Australia. Although this area is now a desert, millions of years ago it was home to an ancient sea teeming with marine microbial life.

” When halite crystals grow in saline surface waters, they trap the parent water in primary fluid impurities ‘, he explains Sarah Schrader Gomez, co-author of the study. ” They can also pick up any solids in the water near or in contact with the face of the crystal. »

Some of these solids have been shown to exhibit properties (size, shape, fluorescent response to UV and visible light) corresponding to those of cells. Prokaryotes And eukaryotesas well as various organic compounds.

” Many of the crystals used in this study show an exceptionally high concentration of microorganisms and organic compounds in the inclusions of the primary fluids. [jusqu’à 40 % d’entre elles en contiennent] “, study authors details.” These allow exceptionally good preservation of organic matter over long periods of geological time. »

Possible organisms

According to the team, these organisms were trapped at the exact time of crystal formation, about 830 million years ago, and some may still be alive, living inside these crystals.” Micro-habitat By feeding on organic compounds or dead cells, which provide the minute amounts of energy needed for an extremely slow metabolism.

If this hypothesis may seem absurd, in 2009, researchers fromUniversity of Pennsylvania He found that bacterial spores trapped in 250 million-year-old fluids of halite survived, and many terrestrial organisms are known to thrive in environments that are not particularly inhospitable.

Confirmation that the microorganisms present in halite did indeed survive would have particularly important implications for the search for present and past life on Earth. Mars. Researchers have determined that many Martian sedimentary formations are similar to those found in Brown So they will be prime targets.