Mines Geology Professor Awarded NSF CAREER Grant

Article and pictures provided by Michelle Pawelski at South Dakota Mines. Pictured: Trevor Waldien, Ph.D., an assistant professor of geology at South Dakota Mines, received a more than $900,000 National Science Foundation CAREER grant to study the uplift of the Black Hills.

With over a million acres of rugged forests and towering peaks, the Black Hills are an adventurer’s dream—offering endless opportunities for hiking, biking, kayaking, rock climbing and camping.

But beyond its outdoor thrills, the region is also a geologist’s treasure trove, its unique landscape holding secrets about Earth’s ancient past. While many answers have been uncovered, mysteries remain—ones that Trevor Waldien, Ph.D., an assistant professor of geology at South Dakota Mines, hopes to reveal with the help of a more than $900,000 National Science Foundation CAREER grant.

“This is truly world-class geology,” Waldien said of the Black Hills. “Universities from across the Midwest bring students here to study the area.”

The Faculty Early Career Development (CAREER) Program is a Foundation-wide activity that offers the NSF’s most prestigious awards in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization. Activities pursued by early-career faculty should build a firm foundation for a lifetime of leadership in integrating education and research.

“The Black Hills are hills now, but there are multiple phases of mountain building recorded in the geology of the Black Hills,” Waldien said.

The most recent phase, the uplift of the Black Hills, happened around 60 million years ago, a short time ago in geological terms. “This is the topography we can see and enjoy with hiking, biking, camping and all the cool stuff we do in the Black Hills. The idea is that the Hills were uplifted, and the Badlands were the sediment removed off the top of the Hills during uplift.”

Long before the uplift, approximately 1.8 billion years ago, the area was the site of another mountain building event – the growth and evolution of North America.

“Disparate fragments of crust came together to make our North American continent, and the Black Hills is one of these places where two crustal blocks came together – one in the east called the Superior Block and one in the west called the Wyoming Block,” Waldien said.

The project aims to study if these two mountain-building phases, happening millions of years apart, are linked.

The NSF grant includes an educational component that will involve undergraduate and graduate students along with local high schools.

“The Black Hills are this inherent weakness in the crust from formation of North America; when the mountain building resumed to uplift the hills, did it exploit that weakness, and is that the reason the Black Hills are here instead of another place,” Waldien said. “We want to use the Black Hills to explain why some continents have isolated mountain ranges hundreds of miles from the coastlines where active plate boundaries typically reside.”

“Using modern geophysical techniques, we can image this crustal suture up through Canada, but we don’t actually see the rocks at the surface anywhere except for the Black Hills,” he said.

To develop an understanding of ancient fault reactivation, Waldien and his team will study the ancient faults exposed in the Black Hills to determine how those faults formed and evolved throughout the tectonic evolution of North America. The project will target specific sites in the Black Hills and use the chemistry of the rocks to determine their ages.

The history of fault motion and rock ages in the Black Hills will help determine the timing and causes of uplift, as well as whether the responsible faults formed during uplift, are older faults inherited from the growth of North America, or both.

The first step is to determine the geological structure related to the uplift. “Historically, it has been described as a big fold, but there is a lot more complexity than that,” Waldien said.

Next, the team will work to determine the age of the rocks by analyzing when they cooled. “As you drill deeper into the Earth, temperatures rise, so when mountains form and uplift occurs, the rocks begin to cool as they are brought toward the surface. By using radioactive elements in specific minerals, we can date this cooling process,” Waldien explained. “This allows us to link cooling rates to particular geological structures (faults), helping us understand when they formed and how they relate to uplift of the hills.”

Once this information is gathered, Waldien said they can identify the primary uplift zones, pinpoint when they developed, and gain deeper insight into the ancient geologic history largely preserved in the heart of the Black Hills, including Hill City, Custer and Nemo.

In addition to the research, the grant focuses on educational outreach. The project will include undergraduate and graduate students who will receive training on how to perform geologic field work and help collect related data.

It will also involve local high schools.

For several years, Waldien has taken high school students on field trips throughout the Black Hills. The CAREER grant will help him expand on this and create a curriculum.

“I plan to develop these field trip guides for local high schools so at the end of five years, they will be able to go out and do it themselves and hopefully lead the students to a future in geology,” Waldien said.

That is what happened with Waldien.

His passion for rocks and the stories they hold began in high school. “I grew up in Oregon, and I had a teacher who was a geologist. He took us on field trips to the beach, and it quite literally changed my life. Many kids don’t realize that becoming a geologist is an option. This is my way of making it more mainstream and showing them that this path is possible,” he said.

The project will strengthen the relationship between the local high schools and Mines, leading to increased interest in geoscience.

With the support of the NSF CAREER grant, Waldien’s research will deepen the understanding of the geological history of the Black Hills while also inspiring the next generation of geoscientists.