Written by EPS Graduate Student Lev Jukna-ParsonsLev Jukna-Parsons
1,500 miles driven. 17 days. Four states. All in pursuit of rare, pristine volcanic glass.
At the tail end of September 2025, fellow grad student Theo and I set out on a trip through the Columbia River Basalt Group (CRBG). It would be part targeted sampling, part reconnaissance, and all rugged exploration of the remote and wild west.
Our route ran from Spokane, Washington, through the Salmon River-carved canyons of north-central Idaho, over the Blue and Steens Mountains of Eastern Oregon, and out to the high desert along the Oregon-Nevada border.
The goal was deceptively simple: collect fresh volcanic glass spanning the entire eruptive history of the CRBG, the youngest and best-preserved large igneous province on Earth. From that glass, we would study the ratio of ferric to ferrous iron trapped inside, which is a window into the redox conditions of its mantle source and the chemical journey these lavas took on the way to the surface. It would provide a small piece of the puzzle of how this enigmatic province formed.
In practice, our goal was anything but simple. Volcanic glass forms only under narrow conditions and rarely survives unaltered and unweathered after 16.7 million years. Worse, our method for measuring redox is exceedingly sensitive to contamination, even from nanometer-scale crystals. We weren't just hunting glass. We were hunting glass so pristine that it would be optically transparent in thin section.
At our first stop, where the Yakima River has sliced through the youngest stacks of CRBG flows, we got lucky almost immediately: fresh glass right at the contact between the Ward Gap flow and the Yakima Bluffs flow below it. Our expectations soared after this early success.
The next several sites brought us back to earth fast. Hours of hiking steep mountainous game trails, scouring flow boundaries and dikes both charted and uncharted, turned up almost nothing, a hard lesson in just how rare intact, multi-million-year-old glass really is. Rain hammered our campsite and our morale in equal measure.
Then, on our last day, with nothing to lose, we pulled a Hail Mary. I'd read a master's thesis on an obscure corner of the CRBG. It had no mention of glass, but I had a hunch. Driving south on the scenic US Route 95 (not to be confused with New Jersey's decidedly unscenic I-95), my eyes were locked on towering sheets of Imnaha Formation lavas while Theo navigated. I finally spotted it: a flow boundary with all the right markers. We pulled over. Wedged between two Imnaha flows was a vanishingly thin sliver of pristine glass. Our goal was met, with little time to spare.
Back in the Rutgers Volcano Lab, the work looks different: picking through samples under a microscope for the cleanest glass chips, then mirror-polishing them into wafers just a few dozen microns thick for analysis.
My fieldwork isn't slowing down. Thanks to a Lipman Research Grant from the Geological Society of America, I'm taking this same approach to the North Atlantic Igneous Province this summer, collecting volcanic glasses in the Faroe Islands to draw links between the redox states of two large igneous provinces a world apart. I hope I have better luck!
