Published on Tuesday December 19, 2006
Dee Breger, Director of Microscopy for the College of Engineering, was quoted in the lead story in the Science section of theThe New York Times on November 14, 2006, for her involvement in characterizing microscopic samples from four huge chevrons (wedge-shaped sediment deposits) in Madagascar.
These chevrons, according to the Holocene Impact Working Group, to which Breger belongs, are megatsunami deposits, evidence that asteroids and comets have impacted the Earth in the last 10,000 years. The small group of collaborators is composed of experts in geology, geophysics, geomorphology, and tsunamis, among other scientific focuses, who hail from the U.S., Australia, France, Ireland, Italy, and Russia. Their findings suggest that catastrophic impacts on Earth could happen every few thousand years, contradicting the existing theory that these impacts occur only every 500,000 to one million years.
Using one of the powerful scanning electron microscopes (SEM) and X-ray microanalyzers in Drexel’s Materials Characterization Facility, Breger and her colleague, Dr. Dallas Abbott, an adjunct research scientist at Lamont-Doherty Earth Observatory in Palisades, N.Y, investigated samples from the chevrons in Madagascar. Breger and Abbott have been working on the oceanic extraterrestrial impact project for six years. In the Madagascar samples, they found benthic foraminifera, tiny fossils from the ocean floor. On closer examination, the microscope revealed drops of iron, nickel, and chrome fused to the fossils. The presence of these three metals indicates an impact in the ocean from a chondritic meteorite, according to Abbott. “Confirmation of the existence of multiple comet and asteroid impacts into the oceans during the span of human history could not easily have been obtained without the use of the Materials Characterization Facility’s instruments,” Breger said.
The New York Times article in which Breger was mentioned was syndicated in Australia, where the story also received significant radio air time, and has led to a segment on the Discovery Channel Canada, which may also be shown in the U.S., as well as internationally. The story has led to a one-hour documentary on the History Channel’s Mega Disasters series, which will include a segment to be filmed in Drexel’s SEM lab.