A Layered Lake is a Little Like Earth’s Early Oceans − and Lets Researchers Explore How Oxygen Built up in our Atmosphere Billions of Years Ago

Little Deming Lake doesn’t get much notice from visitors to Itasca State Park in Minnesota. There’s better boating on nearby Lake Itasca, the headwaters of the Mississippi River. Iowa State University associate professor of geology Elizabeth Swanner and her colleagues need to maneuver hundreds of pounds of equipment down a hidden path made narrow by late-summer poison ivy to launch their rowboats.

But modest Deming Lake offers more than meets the eye for Swanner, a geochemist interested in how oxygen built up in the atmosphere 2.4 billion years ago. The absence of oxygen in the deep layers of Deming Lake is something this small body of water has in common with early Earth’s oceans.

On each of several expeditions here each year, Swanner and her team row their boats out into the deepest part of the lake – over 60 feet (18 meters), despite the lake’s surface area being only 13 acres. They drop an anchor and connect their boats in a flotilla, readying themselves for the work ahead.

Read Swanner’s full article in The Conversation here.