The geology of Southeastern Utah includes many famous formations. In addition to their beauty, to the trained eye, they also include the history of eras and extinctions.
“We can actually look out towards the east, and we see the La Sals that are above Moab, Utah, off to the distance, and that's another volcanic field," said Benjamin Burger, associate professor of geology at Utah State University Uintah Basin Campus.
The formations themselves are striking and perhaps mysterious to many of us. But to Burger, they tell the story of Earth’s past.
“We're going to be passing through a series of Triassic rocks. The rocks that we see in the far distance are the big sand stones, the Navajo sandstone, those are the Jurassic, and Late Cretaceous rocks,” he said.
Leading a field trip in partnership with Green River Rocks, Burger shared his knowledge and enthusiasm with others as he navigated around Temple Mountain and stopped to search for black crystals.
“They're tiny, you almost have to get down here to see them," Burger said as he scrambled around on the ground. "We'll find, maybe, oh here’s a couple.”
The crystals themselves are pyrite, which formed in ancient seas during a period of little to no oxygen. An event that followed an especially significant moment in Earth’s history.
“The end of the Permian period and the beginning of the Triassic, at the onset of the worst mass extinction in Earth's history, that defines a whole new geological era,” Burger said.
Standing directly on top of the catastrophic event that preceded the extinction of the dinosaurs and led to the extinction of up to 97% of all species on the planet about 250 million years ago, Burger surveyed the rocks around him.
“Above us, we have a whole sequence of early Triassic rocks. And at the top, we have a big huge cliff that represents the Sinbad limestone, which is a recovery of a reef complex, the first recovery of this mass extinction," Burger said. "But below us, we have another big limestone unit that's known as the Kaibab and limestone and it is Permian and we find Permian fossils in it.”
Burger himself has published scientific research on this boundary, focusing in particular on the reconstruction of ocean chemistry during the mass extinction.
Check out Green River Rocks to learn more about the festival.
