Some farmers call Iowa’s fertile soil “black gold,” but there may be real gold deep under all that dirt. University of Iowa researchers are studying core samples that could unlock secrets to valuable riches more than a thousand feet down. Ryan Clark, a geologist with the Iowa Geological Survey — an agency housed at the U-I, says geologists are now studying those samples to determine if it’s similar to a massive formation of precious minerals beneath Duluth, Minnesota.

The ten-county region being studied stretches from Decorah in the north, to Elkader and Manchester in the east, and as far west as Vinton. Don’t go out with a shovel, hunting for gold, either. Clark says the top of the potential mineral formation is at least one-to-two thousand feet down. It’s from the Precambrian era, he says, or about a billion years old.