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Protection needed for geological features

WASHINGTON, D.C. — Motorists driving along Highway 36 near Stockton, Utah, may not notice a tall, dam-like pile of gravel and rocks spanning the mile-long gap between two mountains. To the untrained eye the pile doesn’t look like what it really is — an ancient sand bar left from a massive, deep lake that covered the region thousands of years ago.

To scientists, the formation — called the Stockton Bar — is a geologic treasure, containing evidence of thousands of years of geologic history. To the layperson, including those with the authority to grant excavation rights, it looks like a particularly large gravel pile. But to geologists, the Stockton Bar is a prime example of many valuable, but not obviously important, geological features around the country that need to be protected by law.  

“Geologists from all over the world want to come and look at [the Stockton Bar],” said Marjorie Chan, a geologist at the University of Utah in Salt Lake City. The sandbar was built during the last major ice age by waves and currents on what was then a massive lake now known as Lake Bonneville. The lake level changed over thousands of years, at times reaching a depth of 1,200 feet, and at its maximum covered 20,000 square miles.  It was essentially a small sea that finally receded at the end of the last ice age. It left behind beaches, spits and sandbars — including the massive Stockton Bar and the Great Salt Lake.

Lake Bonneville’s waxing and waning burrowed into the Stockton Bar a continuous record of the wave energy, current direction, lake chemistry and precipitation and evaporation levels that geologists can interpret to reveal a timeline of local environmental history that is thousands of years long. “It’s the most important bar of its type in the Western Hemisphere,” said Chan.

But to the untrained eye, the bar remains just a long, massive mound of gravel and sand. Scientists fear that if the bar is left unprotected it could be vulnerable to excavation and development. And the bar isn’t alone — it is one of countless features important to scientists that could be vulnerable if left unprotected.  On Oct. 19 at the Geological Society of America meeting in Portland, Oregon, a group met to discuss strategies to protect the Stockton Bar and other features significant to what they call the “geoheritage” of the United States.

“[There are] all sorts of landforms, fossil sites, and more that should not be broken up willy-nilly,” said John F. Shroder, a geologist at the University of Nebraska at Omaha. “We want to use the geology community to collect the sites that are important to us and gather information so it can be shared and hopefully protected.”

“We have important geologic sites here in the U.S. that we need to conserve because otherwise they will be permanently lost,” said Chan. “They might be textbook examples of geologic features or some historical site that’s associated with geologic features.”

Douglas Prose is a geologist turned filmmaker. “But once a geologist always a geologist,” he said. He feels that the remote, rugged region spanning Oregon and Northern California informally called the “Klamath Knot” also merits protection as a geoheritage site.

“I think it is the most diverse temperate conifer forest in North America and one of the top five in the world,” said Prose. “A large part of that is because of the geology.”

There has been an international effort to preserve scientifically significant features for educational and reference purposes, but the United States has not yet matched the protections offered in other countries, said Chan.

The U.S. has a program for designating National Natural Landmarks to recognize some of the best examples of biological or geological resources in the nation, which is posted on the program’s website. There are 586 landmarks scattered throughout the country and its territories, on both public and private land. They are monitored by the National Park Service, but the designation does not add land use restrictions or ensure public access to the sites, both of which Chan and Shroder consider important to the concept of geoheritage.

Geological features have not been protected to the same degree as endangered species or cultural artifacts. “Some of these features are on private land and they’re unprotected,” said Chan. “There’s just no chance to preserve them the way the system is currently set up.”

Geologists themselves did not always recognize the importance of preserving features. “We used to treat the land like everything was ‘finder’s keepers,'” said Shroder. He described a large group of fossil trilobites (an ancient marine animal) once found in a Boston naval yard. They are appealing fossils, and just the size to be plucked from rocks with pocketknives. Fossils such as these were important in proving that a supercontinent once joined New England and Europe before plate tectonic forces separated them. The trilobites have been stripped from that location.

Prioritizing the sites that they hope to protect is important, both geologists noted. The discussion detailed methods to preserve geologic features and establish geoparks, as well as covering the importance of several specific features, including the Stockton Bar and the Klamath Knot.

“Basically we’re just out to get the U.S. to recognize its [geological] heritage that’s so neat and not cover it up with concrete and houses,” said Shroder.

Geoheritage sites, said Prose, represent “a great new conservation tool that a lot of people can get behind. I want to do a film about the whole idea and get people primed to think about it.”

Chris Gorski reports for Inside Science News Service.

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