Leslie Hayden, who recently earned her Ph.D. at Rensselaer, didn’t shy away from a controversial topic in her studies. In the Earth Science world, core-mantle interactions are divisive.
“Some scientists believe that there is no chemical interaction at all between the Earth’s molten metal core and solid silicate mantle,” she said. “Others believe they see signs of such interaction, but no mechanism or pathway has been found that could deliver metal atoms over distances of more than a few meters.”
Hayden may have discovered such a pathway.
Under the guidance of E. Bruce Watson, Institute Professor of Science at Rensselaer, Hayden used some powerful equipment and creative techniques to uncover a potential pathway for metals to move between the core and mantle of the Earth.
If true, the findings could have broad implications on how geologists understand the deep Earth. They could also one day provide important information on how valuable elemental resources like gold and platinum are deposited. Hayden’s results were published in the Nov. 29, 2007 edition of scientific journal Nature.
How the Experiment Worked
Hayden and Watson developed an experiment that simulated the interface between the core of the Earth and the mantle. The highly pressurized core consists mostly of iron and nickel and is also believed to contain other “iron-loving” elements like gold and platinum. The mantle is comprised of silicate rocks rich in magnesium.
For the experiments they placed a rock that is representative of the material found in the Earth’s mantle in between what they refer to as a source and a sink layer. The source layer was one of the metals found in the core, such as gold, platinum, copper, and other lesser known metals like ruthenium and tungsten. For each metal, the miniaturized core/mantle boundary was then heated to extreme temperatures and pressures to represent conditions in the deep Earth.
Photo credit: RPI/Kris Qua