Schenck rocks out on railroad geological tours

William S. Schenck, a scientist with the Delaware Geological Survey, has been taking students from A.I. duPont High School on Wilmington & Western Railroad tours, observing rock outcrop locations along the way.

Schenck's involvement with the high school started in 2006 when his daughter's earth science teacher asked him to lead a field trip for the class. His involvement with the Wilmington & Western began several years earlier.

“Originally, in 1998, the Wilmington & Western Railroad asked me to write about the geology along the tracks for a publication they were working on. Part of their mission is education, so I did,” Schenck said. “In the end they never published their report so my co-author and I published Delaware Piedmont Geology, including a guide to the rocks of the Red Clay Creek Valley.”

The reason Schenck chose the Delaware Piedmont to study, and to show the A.I. du Pont High students, has to do with the area's geological diversity.

According to Schenck's publication, five distinct rock units can be recognized in the Delaware Piedmont: rocks of the volcanic arc, rocks formed from the mud and sand deposited in the deep ocean that existed between the volcanic arc and the ancient continental margin, rocks that were once sand and carbonates (calcium carbonate) lying on the shallow shelf of the ancient continental margin, and rocks of the ancient North American continent, called Laurentia by geologists.

“The rest of the 94 percent of the state,” explains Schenck, “is covered by layers of sediment of the Atlantic Coastal Plain.”

As far as activities on the field trip, Schenck says that the students “basically look at the rock outcrops and listen to me preach about them. But one thing I always do is pan for garnets in the Red Clay Creek in Brandywine Springs Park. There are lots of them in the stream sediments there, reddish-brown ones and bright lavender ones. It is always exciting to see the bottom of my black gold pan turn red and purple as we pan.”

Schenck's favorite part of the trips, however, is the fact that it allows the students a chance to see rock formations that they might otherwise miss.

“Because it is a field trip on a train, it is a great way to get a lot of people to the rocks almost no one gets to see,” he says.

Article by Adam Thomas
Photos by Kathy Atkinson
Published in UDaily Dec. 10, 2008

For questions and information, contact DGS at, 302-831-2833