Carleton Faculty, Students and Alumni to Present Papers at Geological Society of America Annual Meeting
Several Carleton College students, faculty and alumni will present their research at the annual meeting of the Geological Society of America (GSA), to be held Nov. 12 through 16 in Reno, Nev.
Several Carleton College students, faculty and alumni will present their research at the annual meeting of the Geological Society of America (GSA), to be held Nov. 12 through 16 in Reno, Nev.
Senior Carl Tape will present a poster titled “Evidence for Tides in Cambrian Epeiric Seas of North America,” which is the culmination of an independent summer research project on a roadside outcrop of sandstone near Winona, Minn. He became interested in the outcrop while taking a sedimentary geology class last fall, during which guest lecturer Dr. Anthony Runkel from the Minnesota Geological Survey showed a slide of this particular outcrop and discussed the opportunity for study there. Tape’s study is co-authored by Runkel and Clint Cowan, assistant professor of geology at Carleton.
Tape, who is from Fairbanks, Alaska, lived in Northfield this summer and took trips to Winona to study the sandstone outcrop. The sandstone Tape studied was deposited there 500 million years ago when there was a shallow sea covering the eastern part of the United States. The sandstone formed from sand dunes on the sea floor, which left a pattern of sandy and muddy layers. “You can look at the thickening and thinning of the layers in the sandstone and determine that they were influenced by tides,” Tape said.
The study particularly appeals to Tape, a double major in geology and physics who is preparing his senior physics thesis on tides. “Knowing the physics behind the tides adds an interesting dimension to the story,” he said.
Tape described the notion that an ocean covered this area as “overwhelming” and the evidence that there were tides “convincing.” His presentation at the GSA conference lends more credence to his research. “At first I didn’t think it was important enough to show anywhere, but as I do more reading on the topic, I realize that it’s important to bring this outcrop to the attention of others,” Tape explained.
This project was something that Tape started simply because he was interested in the subject. “It gives you a good perspective on time when you realize that 500 million years ago you could have been standing in this shallow water near Winona with tides coming in,” he explained.
Shelby Boardman, the Charles L. Denison Professor of Geology, who also will present a paper at the annual GSA meeting, describes his study as an extension of research that he’s been doing for most of his career. Boardman has been studying a rock called komatiite in an area near Mount Ouray in central Colorado. The earth has produced less and less komatiite as it has evolved, and Boardman stated that “to find komatiite in terrain younger than 2.5 billion years old is unusual.” He travels to Colorado every summer and brings students with him to work on their own projects or to work as field assistants.
Boardman studies how the earth’s crust in that part of North America came
into being about 1.8 billion years ago. His field work consists of mapping to
understand relationships of rocks to one another and sampling for analysis
back at Carleton. By studying both the field relationship and the chemistry of the rocks, Boardman is able to determine that they represent an old volcanic environment.
“The rocks I’m working with are chemically unusual and because of that, they are particularly valuable in telling us where beneath the earth’s surface the volcanic melts formed,” Boardman said.
In addition to Tape and Boardman, Ed Buchwald, the McBride Professor of
Geology and Environmental Studies, will present a paper. Senior Ani
Kameenui and 1999 graduate Alison Anders are collaborating on a paper on physical erosion in the Copper River Basin in Alaska. Between 40 and 70
Carleton alumni attend this convention every year, and the Carleton geology department holds a reception for its alumni at the convention.
“It’s nice for alums of all ages to meet each other and to hear about Carleton and to reconnect,” Boardman said.