Millions of years ago, there was a near volcanic eruption in southern Illinois.
鈥淚t did not actually erupt lava onto the surface,鈥� said Southern Illinois University geologist Daniel Hummer. 鈥淭he magma got really close to the surface. It sort of punched those topmost layers of rock upwards to form the dome.鈥�
The now-dormant volcano is called Hicks Dome, and scientists like Hummer are fascinated by its geology, as it contains an unusual concentration of rare earth metals and radioactive minerals. Hummer hopes to better understand how it formed these materials.
鈥淲hen you dig in and see what is under the surface on that hill, what you find are some very bizarre types of igneous rocks 鈥� igneous being the type of rock that forms from molten rock formed from magma,鈥� Hummer said.
Hummer and his students have researched the site for several years. He specializes in crystal mineralization and regularly collaborates with other experts at the Illinois State Geological Survey for this work.
鈥淲hen you're all going out there together and collecting samples and looking around, you end up putting everybody's expertise together to learn new things,鈥� he said.
They鈥檝e found radioactive materials like thorium in the rocks as well as many rare earth metals. These rare earth elements are economically important, as they鈥檙e used in manufacturing of electronics and other modern technologies.
Now, Hummer said they鈥檙e trying to figure out how much of these sought-after metals exist in Hicks Dome.
The dome has a gentle slope with a few houses built on top of it. Yet, it remains a place of interest mostly to the scientific community.
鈥淚t's been shrouded in mystery, and not a lot of people realize that this volcanic feature is actually in their backyard,鈥� Hummer said.
For the full conversation with Daniel Hummer and to learn about what he has discovered about the dormant volcano in southern Illinois, listen to the full St. Louis on the Air conversation on , , , , or by clicking the play button below.
鈥�鈥� brings you the stories of St. Louis and the people who live, work and create in our region. The show is produced by , , , and . Ulaa Kuziez is our production assistant. The audio engineer is . Send questions and comments about this story to talk@stlpr.org.
