College of LAS « Illinois

Research

Finding Fouke

Geologist Bruce Fouke doesn't leave many rocks unturned, nor coral or microbes.

Bruce Fouke

Where in the world is LAS professor Bruce Fouke?

The answer to that question could require the assistance of a persistent supersleuth, or at the very least, a Global Positioning System. That's because the multitasking geomicrobiologist is one fast-moving target. When he's not working with students—in the classroom or in a subterranean lab suite in the Natural History Building—Fouke most likely can be found in the field collecting data. But in which field would that be? Geology? Microbiology? Geobiology? Geomicrobiology? The latter two terms are used somewhat interchangeably to refer to emerging disciplines that the LAS researcher plays a lead role in defining.

In Fouke's world, one question naturally seems to lead to another, propelling him in different, yet interconnected, directions. His research may take him to Yellowstone Park's Mammoth Hot Springs to gather travertine samples from the terraced geological formations found there. The goal of that work is to determine how biodiversity and the activities of certain microbes or microbial communities interact with the mineralized spring water to create the terraced architectures present there and in other locations, including Mars.

His work also has led him to Curacao, Netherlands Antilles, an island in the Caribbean, and to Papua New Guinea in the Indo-Pacific Ocean. There Fouke and his research team have collected coral samples, then applied molecular microbiology techniques to identify the deadly microbes responsible for devastation of coral reefs in those and other tropical locations.

Fouke's field of inquiry expanded in yet another exciting direction a couple of years ago when he was introduced to Eric Hostetter. A U of I art history professor and an archeologist who teaches classics courses in LAS, Hostetter has directed excavation projects in Rome for many years.

After a couple of informal mind-melding sessions, the pair—who hail from what at first appeared to be radically different ends of the academic spectrum—realized they had solid grounds for collaboration.

"It started with a colleague of mine in art history who said he knew someone who could date stone buildings," says Hostetter, noting that finding such a person is "every archeologist's dream."

"When I met Bruce, I found that he could not date buildings, but could date the stone," Hostetter says. "He was working on the formation of travertine (a crystalline form of calcite) in Yellowstone, and he had developed methods of dating the formation of the travertine pretty precisely."

Ruins

The encrustation of mineral deposits that accumulated in the walls of ancient Roman aqueducts are travertine as well. The deposits also appear in the reservoir tanks that provided water to the Baths of Caracalla, which Hostetter characterized as "a very important, two-story monumental public building in the late republic, or Augustan Period." In its glory days, the baths—fed by two separate aqueducts—served as a popular leisure-time hot spot for Romans. The building and surrounding grounds were lavishly accented with mosaics and sculpture. In addition to massage rooms and hot- and cold-water baths and pools, the facility housed libraries, shops, bars, and multipurpose halls.

Together with Marina Piranomonte, an Italian government representative and expert on the archeology of the baths, Fouke and Hostetter launched a pilot project in 2000 funded by the Campus Research Board. Its goal, in part, was to determine when water stopped flowing through the channels that fed the baths.

Using methods developed by Fouke and his Yellowstone research team to understand the mechanics of crystallization, the pair hopes to "persuasively demonstrate that water was flowing through that aqueduct at a far later date than most people suspect," Hostetter says. Preliminary studies put that date at about 1050 A.D., "which is a number of centuries after anyone thought it was coming."

Just because water was flowing through the aqueduct at that late date, however, didn't mean the baths were still functioning as baths, Hostetter says. "It means water was flowing for a variety of purposes," for instance, to irrigate orchards or vineyards. "Water was still coming through those aqueducts in some volume, though not necessarily the volume of earlier, because there is no indication of regular maintenance."

Using the same data, Fouke says, "we're also coming up with ideas about what the temperature, salinity, and the chemistry of the water were. On top of that, we're in the process of picking a couple of layers and trying to extract ancient bacteria from those layers—because what we've been finding at Yellowstone is that bacteria get trapped within these crystals."

If Fouke is able to extract ancient bacterial DNA from the travertine samples and identify specific microbes trapped within the crystals, the knowledge could possibly lead to new information about the presence and spread of certain diseases prior to the fall of Rome.

In the meantime, Fouke and Hostetter hope to collect and analyze more samples from the same aqueducts and other water complexes. "If we find out the water is a different age in different parts of the aqueduct," Fouke says, "that's going to tell us important information about the history within the baths."

The researchers expect to publish some of their initial results soon. Fouke hopes to secure new funding to continue the work, because it dovetails so well with other projects in his lab. "All of them fall under this huge umbrella we call biocomplexity.

"For the project with Eric on Rome, for the work on Yellowstone, for the work on the corals, there's a central thread that runs through it all," Fouke says. "All this work is saying, ‘How does every factor involved on Earth's surface interact with each other to create an environment, to create some sort of deposit from an environment?' All I need to have is water, bacteria, and mineral precipitation. And that narrows it down to every single environment on the face of the Earth."

And, perhaps, beyond.

By Melissa Mitchell, July 2004
Photos by Thompson-McClellan, Bruce Fouke, and Eric Hostettler