LARAMIE, Wyo., June 2 (UPI) -- Figuring out exactly what the magma chambers of the Yellowstone supervolcano look like -- or how the magma in those deep-lying pipes behaves -- isn't easy.
One strategy is to study the footprints left behind by the supervolcano's past activity. That's what researchers at the University of Wyoming are doing, looking for clues among ancient granite deposits.
"Every geology student is taught that the present is the key to the past," geologist Carol Frost said in a news release. "In this study, we used the record from past to understand what is happening in modern magma chambers."
Frost is currently on leave from her professorship at Wyoming in order to head up the National Science Foundation's Division of Earth Sciences. She's the co-lead author of a new study on the remnants of ancient supervolvano magma chambers. The paper was recently published in the journal American Mineralogist.
Evidence of one ancient magma chamber, exposed by millions of years of erosion, is found in the 2.62 billion-year-old Wyoming batholith that makes up the Granite, Shirley and Laramie Mountains.
Wyoming Earth scientist and graduate student Davin Bagdonas, who partnered with Frost, collected samples of the batholith from across all three mountain ranges. He found surprising uniformity.
"Only minor variations were observed in granite near the roof and margins," said Bagdonas, co-lead author of the recent study.
Large granite deposits are more common among much older layers of the Earth. Younger strata feature much less granite. The dichotomy suggests the ancient Earth hosted the intense heat required for the formation of granite.
"If these ancient rocks are analogs for the magma systems underlying modern supervolcanoes, then explosive volcanism may have been far more abundant in Earth's past than it is today," researchers wrote in their paper.