Canberra (Australia) – So far scientists have believed that deposits of the clay mineral stevensite can only occur in particularly hostile environments and environments such as volcanic lava or in hot alkaline lakes, so Australian researchers have now discovered living microbes that produce the mineral. The discovery also has consequences for the search for extraterrestrial life – after all, Stevensit has been discovered on Mars.
Like the team around Dr. Bob Burne of the ANU Research School of Earth Sciences at the University of Western Australia, who is currently reporting in the journal “Geology” (DOI: 10.1130 / G35484.1), says that although the Mars stevensite is more likely to be of geological origin, show it Discovery that stevensite can also occur in the environment of biological organisms. For this reason, the deposits of the mineral on Mars would have to be re-examined for possible connections to life forms on the Red Planet.
The microbes discovered by the researchers form a crust of stevensite that protects them and their fragile interior while leaving behind coral-like structures called microbialites.
“Microbialites are the earliest large-scale evidence of life on earth,” notes Burne . “These structures show us how microscopic organisms are able to work together to create huge structures, in some cases similar to the size of today’s coral reefs.” The process can still be observed today, for example in Shark Bay and Lake Clifton in Western Austalia.
” Stevensite has traditionally been thought to require highly alkaline conditions to form, such as volcanic sodium lakes, but the stevensite microbialites we’ve discovered now grow in water that is even lower in salt than normal seawater and has an almost neutral pH Value, “explains the researcher.