Young Explorers Grant

Most of SOPHIA KAST'S research trip was funded through a new program sponsored by National Geographic called Young Explorers Grants. The grants, which range from $2,000 to $5,000, offer opportunities for young people ages 18 to 25 to pursue research, conservation, and exploration-related projects.

Kast and crew: Sophia Kast in Madagascar (below left) with geology
professor Ray Rogers and other team members (above).

MEETING MADAGASCAR

Senior geology major Sophia Kast of Corvallis, Oregon, had the scholarly experience of a lifetime last summer when she was the only undergraduate member of a geological research team in Madagascar. Other team members included Macalester geology professor Ray Rogers, Malagasy graduate students, and guides, drivers, and a cook. After graduation, Kast plans to take a year off before applying to graduate school. Here’s her report of the experience:

The red, pink, and gray sandstones crumble when I touch them. Some have patterns of crisscrossed lines, evidence of currents in ancient rivers, while others are mottled with white powdery squiggles left by 75 million-year-old roots.

These paleosols, or ancient soils, hold so much information—about the plants and animals that lived there, the formations that eroded to form the sediment, and the climate millions of years ago. The tiny clay minerals within these red soils give clues as to how much rain fell when they were forming. These samples are the focus of my two years of geological research into the climate of northwestern Madagascar, specifically the Mahajanga Basin, 75 million years ago.

Paleoclimate research is done for many reasons. In this case the goal was to provide an environmental framework for the dinosaurs that once roamed northwestern Madagascar. Geology professor Ray Rogers has been serving as the geologist for the Mahajanga Basin Project since 1996, and for years has involved his students in his research.
My thesis, which focuses on the clay minerals of Madagascar’s ancient soils, will contribute to a greater understanding of the environment in Madagascar just before the great extinction that eliminated the world’s dinosaurs.

Last summer, I spent almost a month with Rogers and some graduate students in the Mahajanga Basin. We traveled in Land Cruisers down rutted dirt trails and crossed crocodile-infested rivers searching for ancient soils and fossils of dinosaurs, fish, and crocodiles. When we found a good rock outcrop, we’d tumble out of the vehicle and hike to the exposures, stopping occasionally to pick wads of spear grass out of our socks. Usually the rocks would yield a good deal of fossil bone, and we’d spend the day there, measuring sections, describing paleosols, and collecting samples.

Back in Macalester’s Keck Laboratory, I separated the clay out of the samples using a centrifuge, and with the help of a new X-ray diffractometer identified the various kinds of clay in each sample. Different clay minerals form in response to varying amounts of rainfall. This, coupled with an investigation of the weathering of the associated sand grains, gives a good picture of the climate in which the dinosaurs lived.

My summer research experience provided an amazing foundation for my lab work back at Mac, and gave me a personal connection to the Mahajanga Basin Project.