Using equipment in a new laboratory funded by Penn State, geoscientists are able to measure the age of rocks using an advanced mineral-dating process that analyzes the atomic proportions of uranium and lead in the mineral zircon.
IMAGE: David Kubarek
Joshua Garber, a postdoctoral scholar and lab manager, plans to use the lab to study subduction zones – where oceanic plates move below continental plates and is absorbed into the mantle – and particularly the Samail Ophiolite of Oman, an obduction zone where the oceanic plate instead veered towards the Earth’s surface.
When the lab gets a sample, Garber said, they’ll examine it to see the best course of action to take. They can take a sliver, put it under a microscope, and then move on to the crushing phase. The rocks are crushed and the minerals are sorted – just like panning for gold at a much smaller grain size – and the desired minerals are captured. They’re then mounted in epoxy, blasted with a laser, and moved to the mass spectrometer, which identifies the isotopic properties of the sample. The sample is then compared with blast standards to determine its age and composition.