FabulousEmotions

FabulousEmotions t1_iwt4dss wrote

The mounds, called stromatolites, are made from cyanobacteria, one of the first and most prolific lifeforms on Earth. They left behind extremely tiny grains from their bodies after death which became sedimentary rock after millions of years. These stromatolites survive today and can be dated w radioactive dating. http://ircamera.as.arizona.edu/NatSci102/NatSci102/text/extfirstlife.htm

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