A Life in Science

Almost 40 years into a distinguished career as a paleontologist at the University of Florida, Bruce MacFadden will be the first to admit that his interests have moved in recent years toward science education and the training of the next generation of scientists. It is what motivated him to develop the Panama Canal Project PIRE through the National Science Foundation.

But that doesn’t mean he doesn’t still like to get his hands dirty occasionally. Today, he gave a clinic in how to collect rock samples, and it was fascinating.

One of MacFadden’s scientific interests is paleomagnetism, the study of the record of the Earth's magnetic field in rocks. Paleomagnetic rocks are extremely useful to paleontologists because they enables them to precisely date the fossils in those rocks.

So MacFadden’s goal was to collect rock samples to test for their paleomagnetism. After carefully scoping out an appropriate site, MacFadden went to work, armed with a pick axe, a hammer, a chisel, a knife and a compass. Wielding the pick axe, he dug away the soft clay around a promising sample. Then he was ready to take some measurements. Key to determining paleomagnetism is precisely measuring the sample’s orientation relative to magnetic north. Using a special Brunton compass, he oriented the sample to north, writing the compass reading right on the rock. Finally, he used the hammer and chisel to pop the sample from the wall.

Over the course of two hours, MacFadden collected 10 samples from two sites. The carefully wrapped rocks will be shipped to the UF geology department in Gainesville, where their magnetic fields will be measured.

MacFadden’s field notebook is testament to his scientific process. The current version, in use since 2002, reflects his travels throughout the Americas. Inside, are measurements and drawings in neat, precise handwriting. Each follows a convention he has developed over his career. In this case, the first sample from the first site he has collected in 2013 was marked 13-01-A, the second sample was 13-01-B, and so on.

The work was hard and MacFadden was soon soaked with sweat and covered with muddy clay. But he was clearly in his element.

A few hours later, a freshly showered MacFadden was in his other element, presenting a lecture to a hundred faculty and students of the Smithsonian Tropical Research Institute about the use of horse fossils in museums to illustrate evolution. MacFadden argues that many museums, including some of the largest in the United States, have done a poor job of illustrating the complicated evolution of the horse and thereby contributing to public misunderstanding of evolution in general.

Photos: Jeff Gage