Story & Photos by Richard Dayvault…
Ever heard of a cold water geyser? They are rare, but you can visit one about 100 miles west of Grand Junction near Green River, Utah. The story of this unusual phenomenon merits a closer look.
Most geysers erupt because geothermally heated water near the Earth’s surface leaks down along faults and establishes a deep-seated plumbing system. As the water is heated from below, it eventually overcomes the overlying hydrostatic head and the water expands, releasing steam. It has been likened to popping the cap off a carbonated drink and watching it fizz.
Crystal Geyser is not powered by heat, but instead by carbon dioxide gas emanating from great depths along a fault. In 1935, an oil well was drilled along a fault structure to a depth of 2,400 feet. Oil was not found, but carbon dioxide, sometimes associated with hydrocarbon deposits, was tapped. The reason it had remained in the ground and not already dissipated was a confining layer of sediment that prevented upward migration. The well was not properly abandoned and capped, and eventually the carbon dioxide started bubbling up to the surface along this artificial chimney in a spectacular display that we now call the Crystal Geyser.
This geyser truly is analogous to opening a carbonated drink and watching it bubble out. As near-surface water leaks down into a fault zone, it produces enough pressure or head to keep the carbon dioxide dissolved in solution — or nearly so, until the pressure of the gas overcomes the pressure of the water and produces an eruption. After the release of the gas, the pressure is low, and water again fills the drill hole from surrounding fractures.
Eruptions are not exactly predictable, unlike those of the famous geothermal geyser, Old Faithful, in Yellowstone National Park. However, a study conducted in 2005 by personnel from the Lawrence Livermore National Laboratory of 140 eruptions over a 76-day period yielded some interesting facts. They discovered that about two-thirds of the eruptions were of short duration, from 7 to 32 minutes, and the other third were of much longer duration, from 98 to 113 minutes. About twice as many shortduration eruptions occurred as long ones.
Even more interesting: No eruptions lasted from 32 to 98 minutes. The time between eruptions also correlates with the duration of eruption time. The average lag time after a short eruption was only 7.6 hours, but the average lag time after a long eruption was 22.2 hours. No explanation for this bimodal eruption distribution was offered. The team also estimated that 12,000 tons of carbon dioxide are emitted every year from the vent.
A strong eruption may produce a spray of cold water that shoots 40 to 60 feet in the air and last a half-hour or more. Most eruptions are not that impressive.
The day we visited the geyser, it was erupting every few minutes for the hour we stayed, and the spray rarely exceeded 20 feet high. The smell of sulfur was obvious near the geyser, and clear colorless gas disrupted the air as it exited the standpipe. Presumably, this was mostly excess carbon dioxide.
Several small pools of water were continuously bubbling the entire period. Water from the geyser is not only full of carbon dioxide, it is highly saturated with calcium carbonate.
As the water flows over the ground, it evaporates, and the calcium carbonate begins to precipitate and form calcite.
The area downhill from the geyser toward the Green River is covered with a series of travertine terraces that are colored various shades of yellow to orange from traces of iron oxide. Delicate rimrock structures grow as the water evaporates.
The current geyser is not the only location where carbon dioxide springs have deposited travertine in the area. The process has been replayed for thousands if not millions of years. An east/west fault drops Late Cretaceous rocks down and juxtaposes them against older Jurassic rocks. The fault is roughly parallel to the access road as you near the geyser. Look for rusty-colored deposits of layered and faulted travertine to the north of the road.
To find this remarkable little curiosity, proceed to Green River along I-70. At the most eastern off ramp, go south (instead of north to Green River) and follow the road back east and south for about 9.5 miles. The BLM has placed signs that are easy to follow. Sedans can easily make the trip. Enjoy. ***
Timing and Prediction of CO2 Eruptions from Crystal Geyser, UT. Lawrence Livermore National Laboratory UCRL-TR-221731, F.J. Gouveia and S.J. Friedmann, May 2006.
About the author: Richard Dayvault is a geologist based in Grand Junction, Colorado.
This and other select Grand Valley Magazine stories on this site are part of our GV Classics Collection. This story was featured in the April 2010 issue of Grand Valley Magazine (c) 2010.