They used radiometric dating, X-ray fluorescence spectrometry, and chemical analysis of the minerals to verify that the volcanic ash was all from the same ancient super-eruption.
The impact also created shocked quartz crystals that were blasted into the air and subsequently fell to the west into the inland sea that occupied much of central North America at that time.
The scientific journal Geosphere recently published two of their papers detailing the discoveries.
Despite their enormous size, the supervolcanoes have been hidden in plain sight for millions of years.
Hundreds of other students were involved with the geologic mapping of the volcanic areas.
The skills and experience each student gained along the way have opened doors to graduate schools, employers and entrepreneurship. "Supervolcanoes discovered in Utah: Evidence of some of the largest eruptions in Earth's history." Science Daily. When water interacts with magma, it can dramatically increase the explosivity of the eruption.