A world leader in ancient Earth geology
From the outside, Webster 1026 looks just like any other college laboratory except for one small detail: several pairs of shoes lined up near the door.
WSU geologist Jeff Vervoort slips off his shoes, places them among the others, and heads into a small antechamber where he dons rubber slippers, a blue coat, and latex gloves. He then opens a pressurized door into the laboratory’s spotless interior.
It is a cleanroom where researchers take intense precautions to keep out even the tiniest particles. Dust, hair, and mere flakes of skin pose a contamination risk to samples of materials being prepared for analysis.
The cleanroom is part of the WSU Radiogenic Isotope and Geochronology Laboratory, one of only a handful of facilities in the world where scientists analyze characteristic isotopes of rocks, minerals, and meteorites to determine their ages and how they formed.
Vervoort is the lab’s director and a leading expert in early Earth geology. His research analyzing hafnium isotopes in meteorites has helped scientists determine the composition and characteristics of our planet and other objects in the solar system. Utilizing the School of the Environment’s suite of high-tech instruments—electron microprobes, micro drills, mass spectrometers, wavelength spectrometers, and more—which occupy two floors of Webster Hall, Vervoort and his colleagues analyze a wide range of Earth and planetary materials, including rocks and minerals of all ages, modern sediments, meteorites, and volcanic matter.
“The old way of doing geochemical analysis was to take a rock and dissolve it to determine its isotopic composition, but it’s increasingly obvious that we must take a different approach to complex rocks and meteorites with multiple components,” Vervoort said. “Our combined lab is one of the few in the world with the capability to isolate and analyze individual elements in rocks and minerals using a mix of chemical processes and mass spectrometry.”
Collaborating across campus and worldwide
Scholars from across the University and around the globe, in disciplines ranging from anthropology to physics, engineering, biology, hydrology, chemistry, and even veterinary science, regularly consult with Vervoort and employ WSU’s geoanalytical capabilities to advance their research. Geologists from as far away as China send rocks containing garnets and zircons to help determine when continents collided and mountains formed. Researchers in mining and energy exploration send deep-earth samples for geochemical analyses.
In the geochronology lab, graduate student Alex Johnson demonstrated how he extracts isotope information from zircon crystals that are billions of years old .
Rocks containing microscopic zircon minerals are first crushed into sand-sized grains. Next, the zircons are isolated in a series of steps using water and magnetic separators and heavy mineral liquids. The zircons are then mounted in epoxy and polished, revealing their interiors. A laser is used to vaporize the zircons into an aerosol which is swept into an inductively coupled plasma mass spectrometer. Finally, the zircon atoms are ionized, accelerated through a magnetic field, and separated based on their atomic mass. The differences in isotopic ratios are measured in the mass spectrometer and used to determine the mineral’s age and physical history.
“The isotope work we do is kind of like taking a geological fingerprint,” Johnson said. “We can determine the time the rock formed as well as its prehistory.”
Insights to Earth’s great mysteries
Vervoort is currently collaborating with scientists at the Massachusetts Institute of Technology to answer two of the longest standing mysteries in the field of geology: when and how did Earth’s continents form?
Scientists know the window for “when” is between 2.5 and 4 billion years ago. Most of Earth’s surface during this period, the so-called Archean Eon, has long since been destroyed by erosion and plate movements. Any trace minerals that remain were remixed into larger rock formations over millions of years and are exceedingly rare.
Vervoort and his collaborators are now studying one of the few known samples from this period. The specimens are from Canada’s Northwest Territories and contain 4-billion-year-old zircons that formed from magmas that crystallized to form Earth’s early crust.
“One of the models we are converging on now is that the continents didn’t form early on,” Vervoort said. “We think that the Earth, 4.5-4 billion years ago, may have resembled modern day Venus where you have vertical tectonics instead of tectonic plates moving more horizontally along the surface as they do today. And then, around 3.8 to 3.5 billion years ago, there was a transition to the geology we have today and the continents started to form.”
The ‘big picture’ of natural science
At WSU, Vervoort teaches introductory oceanography, supervises four MS and three PhD students, and works with two geology postdoctoral researchers. His investigations of ancient rocks have taken him to most of the world’s continents, including Antarctica where he spent more than a month studying the Transarctic Mountains on a project funded by the National Science Foundation Office of Polar Programs.
His personal interest in geology goes back to his childhood in northern Minnesota where he walked rocky shorelines examining stones he found along the way. Always interested in the “big picture” of natural science, he earned a bachelor’s degree in English and zoology before finding his passion and earning a doctoral degree in geology at Cornell University.
“Earth science combines physics, chemistry, mathematics, and biosciences to help us explain the natural world,” he said. “It helps us understand the landscape around us—the mountains, the rivers, the lakes, the oceans, the deserts. It explains why the physical world is the way it is. That is what I love about it.”