Due to its special karstic geology, submerged sinkholes and cracks are opening in the floor of Lake Huron.
From these cavities – ranging from 1 to 93 meters (3 – 279ft) deep – emerges groundwater, which contains bacteria of 300 million years ago.
Yes! And these bacteria are close cousin to those found in some of Earth’s most extreme environments, such as deep-sea hydrothermal vents and ice-locked Antarctic lakes. This sort of life was not supposed to be occurring in the Great Lakes. Do these submerged sinkholes in Lake Huron represent a window to the ancient world?
Although most of the water in the Great Lakes comes from rain and snowfall, Lake Huron’s sinholes are filled with groundwater rich in salts and dissolved sulfur. And their source is still unknown!
Moreover, it is still unknown if the microbes are truly primordial. But first tests show that the sinkhole bacteria can easily photosynthesize in sulfur-rich water and freshwater. These conditions were required to survive in shallow, primeval seas that existed billions of years ago.
The exposed limestone bedrock at the bottom of the lake — a landform called karst — was once the floor of a Silurian Sea that 300 million years ago blanketed what would become North America.
Sinkholes are merely terrifying. However, the sinkholes in Lake Huron bear something mystical and life-oriented. Amazing!