Geology graduate student Collin Jensen isn’t the first Mormon geologist to wonder how the granite of Little Cottonwood Stock formed.
“James E. Talmage, not only was he a prominent figure in the Church and an apostle, he was also a geologist,” Jensen said. “He was the first person who looked at Little Cottonwood Stock 100 years ago and said, ‘No, this thing isn’t Proterozoic [over 500 million years old]. . . . I think this thing is a lot younger.’”
Unfortunately for Talmage, author of the famous book Jesus the Christ, the technology of the 1910s was not advanced enough to prove his hypothesis. That’s where Jensen comes in.
“Now we can figure out, from our studies, that Little Cottonwood Stock is thirty million years old, plus or minus five-million years for some of the other parts of it,” Jensen said. “Much more accurate than James E. Talmage could ever do.”
The connections between Mormonism and Jensen’s thesis research into the origins of Little Cottonwood Stock don’t end with James E. Talmage. Beyond being just an interesting geological subject, Little Cottonwood Stock is also the source of the granite used to build the Salt Lake Temple.
And what’s most interesting is that the temple-building Saints didn’t have to travel very far to find their building materials.
“They didn’t actually drill straight into the mountainside to get much granite,” Jensen said. “They did that a little bit, but for the most part the granite that they got was brought to them by the glaciers.”
During the most recent ice age, approximately 12,000 years before Brigham Young led the Saints to Utah, glaciers in Little Cottonwood Canyon plucked up large chunks of granite and dropped the boulders at the mouth of the canyon when the ice melted.
“Glaciers act like a bulldozer,” Jensen said. “They rip up chunks of rock and they will carry down whatever is in front of them. It doesn’t matter how strong the rock is, the glacier is stronger and it will carve it out.”
This glacier delivery service put the granite blocks a mere twenty miles south of Salt Lake City. For Jensen, this is not just a geological coincidence.
“It’s cool to see that in all things the Lord prepares a way,” Jensen said. “Some would say it is fortuitous, but I don’t think it is fortuitous at all—I think that was by design.”
Because of his research, Jensen sees a deeper meaning in the outer walls of the temple.
“If you look closely at [the temple], there are these little inclusions or ‘mafic enclaves’ of darker rock,” Jensen said. “President [Gordon B.] Hinckley referred to those black splotches as blemishes which gave character to the Salt Lake Temple and Conference Center. My thesis adviser, Dr. Keith, says, ‘oh, those things just make it more beautiful! I don’t see them as blemishes. I see them as something that makes it even more beautiful and aesthetically pleasing.’”
So, next time you visit Temple Square or pass Salt Lake City on I-15, check out the granite in the temple walls—just remember that you’re not the first to take a look.