Study at NSLS may help reveal the role of mantle oxidation states in understanding the Earth’s deep interior.
Molten lava erupts from Earth’s mantle at a scorching 1000 to 1300 degrees Celsius. But when the hot liquid rock spews from a mid-ocean ridge volcano, the lava succumbs to the seafloor’s freezing waters and crushing pressures – solidifying into volcanic glass. Geologists Elizabeth Cottrell, from the Smithsonian National Museum of Natural History, and Katherine Kelley, from the University of Rhode Island, analyze mid-ocean ridge basalt glass to better understand Earth’s deep interior and ancient past. Their work hints at a connection between the mantle’s geochemistry and the carbon reservoirs stored for billions of years in the depths of our planet.
The pair used x-rays produced by the National Synchrotron Light Source (NSLS) at the U.S. Department of Energy’s Brookhaven National Laboratory to examine a large collection of deep-sea glass in order to uncover geochemical “fingerprints” left behind during the magma’s ascent and eruption.
“In our study we looked at lavas from volcanoes on the sea floor all around the globe, and we measured the oxidation state of iron,” said Cottrell. “We wanted to know if that could tell us something about the history and character of the mantle that melted to make those lavas, and then froze to form the glass.”
Read more at: Phys.org