The Friends of the Florissant Fossil Beds

While the paleontology of Florissant has been studied extensively, the geology is less well-known. This summer and over the next few years, Dr. Charles Ver Straeten, a sedimentary geologist from the New York State Museum, will be studying the preservation of volcanic ash layers in the late Eocene Florissant Formation, which dates to about 34 Ma (million years ago).

Just like living organisms that died and fell into ancient Lake Florissant, ash layers aren’t always preserved after deposition. Animal activity can disturb and even destroy thin ash layers, and ash layers are also subject to destructive chemical processes. Understanding how ancient ash layers are preserved–or altered–helps scientists to better interpret the geological record of volcanism.

Ver Straeten is also examining ash layer preservation at the ~48 Ma early Eocene Green River Formation in and around Fossil Butte National Monument. His original ash preservation studies were on much older Devonian rocks (416 to 359 Ma), and he plans to begin a research collection of ash slides as a resource for other researchers.

-Melissa Barton

Photos: Ver Straeten and park paleontologist Dr. Herb Meyer discussing sampling possibilities (top); layers of volcanic ash-clay, pumice, and diatomite at the “Scudder Pit” interpretive site (left); Ver Straeten, Meyer, and summer paleontology interns Kathy Salas and Eva Lyon (right).
Photographer: Melissa Barton