Jeffrey Trop

"It's incredibly gratifying to take students out and show them how the Earth really works."

Associate professor of geology

Jeff Trop grew up hiking and canoeing in northern New York. Today, as an associate professor of geology, he still loves exploring the earth.

Trop studies the geology of Alaska. With explosive volcanoes, large-magnitude earthquakes and shifting continental plates, the forty-ninth state is the most tectonically active area in North America.

“If we want to understand how continents grow, Alaska is a wonderful natural laboratory,” Trop said. It is also relatively unknown.

Geological observations
Each summer Trop and one or two Bucknell students are dropped off by helicopter or bush plane to backpack through remote mountain ranges, making geological observations and collecting samples for analysis back home.

One of Trop’s goals is to understand past environmental conditions. In 2006, he and John Witmer ’07 discovered a remarkable outcrop of marine fossils in the Wrangell Mountains of southeast Alaska. The exposed sediments revealed conditions of the Triassic-Jurassic boundary, which occurred about 200 million years ago at a time of a major mass extinction.

Such lessons from the earth’s past may help us understand the present.

Rapid deglaciation
“During my experience over the past 15 years, I’ve seen arctic warming firsthand,” Trop said. “We’re watching geology become unearthed by this rapid deglaciation, so it’s a great place to take students to look at an active landscape that is evolving in response to climate change.”

Alaskan geology might also illuminate processes on Mars. Trop and Bucknell geology professor Craig Kochel have been comparing Alaskan alluvial fans to similar features seen in images of Mars. Understanding the geological events that create these structures on Earth could indicate where water has been on Mars.

Trop and Kochel, in collaboration with students Christine Kassab ’08 and Steve Smith ‘08, are also studying how northeast and southeast-facing shorelines are differently affected by storms in the Outer Banks of North Carolina. One goal of the project is to educate the public on the natural cycles of these shifting islands.

“Native Americans did not set up permanent structures on barrier islands,” Trop said. “They realized that major storms displaced large amounts of sediment that make up the islands.”

Today, with major structures on the islands, huge amounts of money are spent to fight the natural progression by moving sand that has washed over the islands back to the windward side.

Trop’s love of field work carries over to his teaching. His courses are field based, taking advantage of the spectacular geology of central Pennsylvania.

“It’s incredibly gratifying to take students out and show them how the Earth really works,” Trop said. “They are going to spend the rest of their lives walking around on it, so it’s good for them to know something about the processes and features that shape the earth.”

Teaching areas

  • Evolution of the earth
  • Global change – past and present
  • Paleontology
  • Physical sedimentology and stratigraphy
  • The sixth extinction

Research interests

  • Evolution of sedimentary basins along convergent plate margins
  • Tectonics and sedimentation of forearc, fold-thrust, and strike-slip orogeny
  • Sedimentology and petrology of clastic depositional environments

Recent publications

  • Trop, J.M., Latest Cretaceous Forearc-Basin Development along an Accretionary Convergent Margin: South-Central Alaska: Geological Society of America Bulletin, accepted.
  • Trop, J.M., and Ridgway, K.D., 2007, Mesozoic and Cenozoic tectonic growth of southern Alaska: a sedimentary basin perspective: in Ridgway, K.D., Trop, J.M., and Glen, J.M.G., eds., Tectonic growth of a collisional continental margin: Crustal evolution of southern Alaska: Geological Society of America Special Paper 431, in press.
  • Manuszak, J.D., Ridgway, K.D., Trop, J.M., and Gehrels, G.E., 2007, Sedimentary Record of the tectonic growth of a collisional continental margin: Upper Jurassic-Lower Cretaceous Nutzotin Mountains Sequence, eastern Alaska Range, Alaska: in Ridgway, K.D., Trop, J.M., and Glen, J.M.G., eds., Tectonic growth of a collisional continental margin: Crustal evolution of southern Alaska, Geological Society of America Special Paper 431, doi:10:1130/2007.2431(14), in press.
  • Trop, J.M., Szuch, D.A., Rioux, M., Blodgett, R.B., 2005, Sedimentology and provenance of the Upper Jurassic Naknek Formation, Talkeetna Mountains, Alaska: bearings on the accretionary tectonic history of the Wrangellia composite terrane: Geological Society of America Bulletin, v. 117, no. 5/6, p. 570–588.