DEVELOPMENT OF A GEOLOGIC GUIDE FOR FLORISSANT FOSSIL BEDS NATIONAL MONUMENT

The Florissant Fossil Beds National Monument Geologic Guide is designed to acquaint visitors with the geologic history of the monument with a self-guided tour. The geology includes the Proterozoic granitic pluton of the Pikes Peak Granite as well as Eocene volcanic, fluvial, and lacustrine units of the Wall Mountain Tuff and Florissant Formation. This guide communicates the geologic significance of Florissant Fossil Beds National Monument by relating these stratigraphic and igneous rock units to geologic events, then indicating specific locations to view tangible examples of the area’s geologic history. The guide begins with a small scale 1:117,000 map of the monument as well as areas to the north and south. The late Eocene Florissant Formation, the primary fossil-bearing formation in the area, is initially shown on this map as a homogeneous unit, showing its broader relation to the surrounding units. This view illustrates an outline of the ancient lake. The next geologic map is a 1:20,000 perspective showing the rock units and topography only within the monument’s boundaries. This map differentiates the Florissant Formation into its six separate lithologies previously defined. The third map shows an enlarged 1:10,000 perspective of the principle hiking trails within the monument, indicating specific points of geologic interest along those trails. Those points are explained below the map with photos and texts describing geologic significance. A table of waypoints is provided for GPS navigation.

The rock units portrayed on the geologic maps are then put into context with an illustration of a stratigraphic column. Each rock layer is further described with photos in outcrop and as a hand sample. Fossils are illustrated for the fossiliferous layers. In depth descriptions of each rock layer include lithology, deposition, paleontology (if applicable), and locations where outcrops can be viewed. The guide ends with a brief text describing the geologic history of the area and a customized time scale, placing the deposition of the Florissant Formation and other surrounding units into context with the entirety of geologic time.