Carleton Geology Alums In The News
- September 14, 2010
Dinosaurs overshadowed mammals for most of the Mesozoic, but evidence of actual dinosaur-mammal interactions are very rare. On the mammalian score, a specimen of the relatively large Cretaceous mammal Repenomamus robustus described in 2005 was found with the bones of baby dinosaurs in its stomach—it had apparently fed on young Psittacosaurus shortly before it died. A new set of fossils from southern Utah, though, evens the score for the dinosaurs.
In Utah’s Grand Staircase-Escalante National Monument, within the 80-million-year-old rock of the Wahweap Formation, paleontologists have discovered evidence that small predatory dinosaurs dug down into the soil to reach the burrows of small mammals. As reported in the journal Geology, the vestiges of these events are left behind as traces within the rocks—scratches made by dinosaurs and dens used by mammals—and by looking at them together scientists can replay what might have happened during those Late Cretaceous days at the end of the Mesozoic era.
Together the scratches and burrows tell of ancient interactions we could only previously infer on the basis of bones. It most have been terrifying for those small mammals, hearing the predatory dinosaur scratching deep into the ground in the hopes of catching them.
Edward L. Simpson, Hannah L. Hilbert-Wolf, Michael C. Wizevich, Sarah E. Tindall, Ben R. Fasinski, Lauren P. Storm and Mattathias D. Needle (2010). Predatory digging behavior by dinosaurs Geology, 38, 699-702
In findings that push back the clock on the scientific world's thinking about when animal life appeared on Earth, Princeton scientists may have discovered the oldest fossils of animal bodies, suggesting that primitive sponge-like creatures were living in ocean reefs about 650 million years ago. The shelly fossils, found beneath a 635 million-year-old glacial deposit in South Australia, represent the earliest evidence of animal body forms in the current fossil record by at least 70 million years.
Princeton geosciences professor Adam Maloof and graduate student Catherine Rose happened upon the new fossils while working on a project focused on the severe ice age that marked the end of the Cryogenian period 635 million years ago. Their findings, published in the Aug. 17 issue of the journal Nature Geosciences, provide the first direct evidence that animal life existed before -- and probably survived -- the severe "snowball Earth" event known as the Marinoan glaciation that left much of the globe covered in ice at the end of the Cryogenian.
- July 20, 2010
BANGOR, Maine — Bess Koffman is spending her summer watching ice melt.
But Koffman, 29, of Orono doesn’t stand around a lab at the University of Maine’s Climate Change Institute 10 hours a day monitoring any ordinary frozen H2O.
Her ice is ancient. Some sections of the ice cores Koffman is melting this summer are 2,000 years old.
On Tuesday, she spent much of the day looking for evidence of dust in the melting ice from a volcano that erupted in A.D. 186 in New Zealand to see whether it had drifted as far as western Antarctica.
“It would be new and exciting to document that,” the graduate student said Tuesday morning in a demonstration of her research for Bangor-area news outlets. “This volcanic eruption has not been documented in Antarctica before.”
We are very proud to announce that Laura Bazzetta '10 has received an Outstanding Student Paper Award for her presentation at the 2009 American Geophysical Union fall meeting in San Francisco, California. Her paper was entitled, "Linking river morphology to larval drift of an endangered sturgeon."
Good work Laura!!
- July 12, 2010
Laura Peterson, Luther College assistant professor of environmental studies, is the co-author of "Tropical Ocean Temperatures Over the Past 3.5 Million Years," a research paper published in the June 18 issue of the journal Science.
The paper explains the findings of a research project led by Brown University in which Peterson participated. The research team's discoveries that suggest that fluctuating carbon dioxide levels explain why temperatures in tropical oceans and arctic waters have changed together for the past 2.7 million years.
The research team analyzed cores taken from the seabed at four locations in tropical oceans: the Arabian Sea, the South China Sea, the eastern Pacific Ocean and the equatorial Atlantic Ocean.
- June 28, 2010
Rolling north through Northfield and Carleton’s Cowling Arboretum is the Cannon River. Although often enjoyed by sunbathers and fishermen along its banks, many people don’t think of the Cannon as a means of transportation. This spring, three friends and I canoed the Cannon from downtown Northfield—and on to Red Wing, Minnesota, where it joins the mighty Mississippi River. The journey lasted 13 hours and covered an ever-changing tableau of landscapes and wildlife.
We are paddling along the western edge of the North American continent, where land meets water. For this week's Notes from the Trail, we asked Ellen Root, our geology expert, to provide us with an explanation of the geology of this region. Here is what she told us:
You may already know that sea level on Earth changes over time. This depends on temperatures on the whole Earth as well as the amount of ice that is frozen in glaciers and the polar ice caps. At different times in Earth’s history we could have been traveling through what is now land far from the ocean’s edge or among islands that presently lie deep beneath the surface of the water. Today we want to talk about another aspect of the coastline we see each day. We want to look at the rocks that form the support structure for the plants, animals, people, and buildings we have encountered as we paddle along the Canadian coast. Many people think of rocks as solid and immovable, but every day they are moving, very slowly, on a scale so large it can be difficult to comprehend. The science that explains this process is called Plate Tectonics.
- June 18, 2010
A service of celebration and remembrance for Eiler Henrickson ‘43, Carleton College Charles L. Denison Professor of Geology emeritus, was held during Reunion 2010. The service featured readings, reflections, and music, including a performance by several of Eiler's former students.
Eiler taught geology at Carleton for 41 years and coached the Carleton wrestling team for 12 seasons. He retired in 1987 and passed away on Dec. 10, 2009.
See a video of the "Sometime Geology Field Trip Band" performing "Eiler's Schottische" at the June 18 memorial service, along with two short documentary videos by Aleshia Mueller '01, at the Remembering Eiler Henrickson page.
- June 15, 2010
We have just learned that Nate Evenson ’10 was recognized for the “Outstanding Undergraduate Oral Presentation” at this spring’s Cordilleran Section of the Geological Society of America meeting in Anaheim, California. Nate’s title was, “U-Pb zircon geochronology and provenance of the Paleogene–Neogene Kootznahoo Formation, southeast Alaska.” The award includes a check for $400.
- May 25, 2010
We are extremely pleased to be able to report that the Dean of the College, Beverly Nagel, has just announced faculty promotions for this year, and Clint Cowan '83 is being promoted to full professor effective September 1, 2010. Congratulations, Clint!
Professor Clint Cowan was educated at Carleton College and earned his M.Sc. in Geology from The University of Michigan in 1985. After receiving his Master’s degree, he worked as an exploration geologist with Exxon in Houston, Texas, for two years before entering the Ph.D. program at Queen’s University in Kingston Ontario. He earned his Ph.D. in 1992, and taught at Carleton for one term as a Visiting Professor before taking a position as an International Staff Geologist with Royal Dutch Shell in The Hague, Netherlands. Five years later, in the fall of 1997, he returned to Carleton and began his present teaching career.