Bacteria built rocks

"

In the story of life on earth, single-celled, microscopic organisms have built our planet in spectacular landscapes such as the white cliffs of Dover and these banded iron formations in Pilbara, Australia (above). "Microbes...have dominated that story for three billion years. In fact, microbes have written it, forming rocks and giving rise to the oxygen in the atmosphere, and underpinning many other atmospheric and geological processes that can span millennia." Life at the Edge of Sight, Roberto Kolter and Scott Chimileski http://harvardmagazine.com/2017/09/microbes-in-soil