Late Eocene volcanic activity of vastly different styles produced a variety of products and landforms between Pikes Peak and South Park. They mantled and modified the landscape which had been developed on the Precambrian basement rocks more than a billion years older. Pyroclastic flows from the Sawatch Range blasted across a surface of low relief 36 million years ago, filling valleys with the resistant Wall Mountain Tuff. Lava flows, mudflows, and ash from the Guffey volcanic center created and then buried Lake Florissant about 2 million years later. This seminar begins with an introductory overview at the Monument followed by a 3/4-day field trip to the Guffey area and back via two different routes to visit the rocks produced during these volcanic episodes.

Meet at the Yurt at Florissant Fossil Beds National Monument.