Marbled with rich garnet, amber, and gold tones, a collection of petrified wood embellishes the slope alongside the Ho Science Center. Shining with a glossy luster, the pieces almost seem like man-made sculptures — but they are millions-of-years-old geological wonders.
The Petrified Woods exhibition, presented by the Robert M. Linsley Geology Museum and geology department, began showing this spring.
Petrification occurs when trees and woody vegetation are buried in mud or volcanic ash. Over thousands of years, mineral-rich waters infuse the wood. Its cells are slowly replaced by silica, which hardens into opal or quartz. “The colors of each piece of wood come from impurities of metals, like iron, manganese, and cobalt,” explains Rich April, the Dunham Beldon Jr. Professor of geology emeritus. He and Di Keller, senior lecturer in geology, are the Linsley curators who coordinated the exhibition.
For April, the standout specimen is a black beauty from the island of Java in Indonesia. Buried in the ash of a volcanic eruption approximately 20 million years ago, the mostly black tree trunk is now lined with white stripes of pure silica. He calls the piece “sheer magnificence.”
Keller’s favorite is a 700-pound fossil stump from 385 million years ago. It was discovered in Gilboa, N.Y., (only approximately 75 miles east of Colgate) in “the oldest known petrified forest,” as described in 1927 by Winifred Goldring, the first woman in the United States to be appointed as a state paleontologist. “There’s just something about the textures on it, and there’s an iridescent play of colors in some areas because of different minerals that are oxidizing out,” Keller says. “And I love the story of it too,” she adds, referring to Goldring’s accomplishments as a female geologist.
Also in the exhibition: three brown and tan slices from Madagascar, as well as 11 pieces from lands surrounding Arizona’s Petrified Forest National Park. “Most of the rainbow-colored petrified wood that you see in the United States comes from that area,” April says.
He and Keller began organizing the exhibition last spring when they realized University museums would likely be closed for a while due to the pandemic. On the heels of Linsley’s Bicentennial exhibition, Petrified Woods began taking shape. As new trees were being planted on campus in preparation for Colgate’s third century, this exhibition represented “a lasting forest,” Keller notes.
In addition, “it seemed appropriate to have an exhibit that would show Colgate’s beauty and perseverance through some very difficult times,” April says. The two put the finishing touches on the exhibition in November — just in time for snow to blanket campus and cover their hard work. But, this spring, as the snow melted, the creations gradually began to show themselves. April says: “It’s making its debut by nature’s hand.”