#Qualif
A team of #geologists found an unusual #ecosystem in the Atacama Puna region, on the border of #Argentina with Chile, that could provide important information about how #life originated on #Earth and Mars.
Within this desert plateau, located at an altitude of 3,660 meters above sea level, a system of 12 lakes is found surrounded by extensive salt plains.
Under the clear waters of these lakes, which extend over an area of 101,171 square meters, scientists found 4.6-meter-wide hills of rocks covered in microbes.
According to scientists, these structures resemble the first known life forms on our planet, which are called stromatolites (sedimentary rocks that contained organisms that are the oldest microbes on Earth). These are thought to have existed during the Early Archaic period, which was characterized by the absence of oxygen in Earth’s atmosphere.
Geologist Brian Hynek, associate professor of geological sciences at the University of Colorado Boulder, said that this environment is “strange,” and unlike any other, adding: “This lake could be one of the best modern examples of the first signs of life on Earth.” “It is amazing that things like this can still be found on our planet,” he stressed.
Stromatolites still form today in many marine and freshwater habitats, such as those found off the coast of the Bahamas, but they grow much smaller than their ancient counterparts. However, compared to their primitive ancestors, which reached up to 6 meters in height, modern stromatolites are relatively smaller, grow passively, and feed on grains of sand and debris floating in the ocean.
The Atacama stromatolites were made mostly of gypsum, a mineral common in fossilized stromatolites, but absent from modern examples.
“We think these mounds are actually growing from microbes, which is what was happening in older mounds,” Hynek said, noting that until now, it is not known how these organisms were able to reproduce in such a hostile environment.
On the other hand, scientists stated that these structures could provide details about how the first signs of life appeared on the red planet.
“If life on Mars evolved to the fossil level, it would be like this,” Hynek continued, adding that “understanding these modern societies on Earth can tell us what to look for when looking for similar features in Martian rocks.”
Geologists plan to conduct further experiments to confirm that these stromatolites are what build the rock formations in which they are found, as well as to analyze the conditions that allow them to survive in the desert.
