Team member John Holloway, emeritus faculty in the School of Earth and Space Exploration and ASU's Department of Chemistry and Biochemistry, designed and built the hydrothermal reaction vessels necessary for testing. At ASU's new Omni-pressure Lab, simple compounds such as water and carbon dioxide are placed in the inert gold capsules and then tested.
"The samples are held at temperatures up to 300 degrees Celsius and pressures of 250 atmospheres, equivalent to the bottom of the ocean (2,500 meters) or slightly higher, for periods of hours to weeks," explains Holloway. "They are then quenched to ambient conditions and we analyze the products using gas chromatography and mass-spectrometry."
The results of past similar experiments have shown that the concentration, variety, and complexity of compounds all increase with time, and are strongly influenced by contact with minerals during the experiments.
"It will be important to find out if the mixture of compounds we make in the lab looks anything like the organic compounds that are found in the deep subsurface," says Hartnett. "If they do, then maybe this is how they formed - just rocks, hot water and simple carbon compounds. If they don't, well, we need to figure out what else is required."
"Lots of researchers have looked at individual aspects of the questions we're asking, but this is one of the first - or maybe the first - attempt to look at these high-temperature water-rock-organic processes from an integrated experimental and theoretical standpoint," Hartnett says.
A project of this caliber requires a team with a wide-range
|Contact: Nikki Staab|
Arizona State University