The Fountain Formation is found along the Front Range of Colorado. To the north, the Formation
unconformably overlies
Precambrian granite and gneiss. To the south, it overlies Mississippian, Ordovician and Devonian Limestones, as well as Cambrian sandstones. Outcrops of the formation typically dip steeply to the east.
Depositional environment The formation was formed by the erosion of the
Ancestral Rocky Mountains, and deposition by fluvial processes as
alluvial fans. The characteristic predominant red color and the composition of the Fountain reflect that of the
granites and
gneisses from which it was eroded.
Notable outcrops • Flagstaff Mtn Park, near
Boulder, Colorado •
Flatirons, near
Boulder, Colorado •
Red Rocks Park and Amphitheater,
Morrison, Colorado •
Roxborough State Park, south of
Denver, Colorado •
Perry Park, west of
Larkspur, Colorado •
Garden of the Gods in
Colorado Springs, Colorado •
Red Rock Canyon Open Space in
Colorado Springs, Colorado • Red Canyon Park near
Cañon City, Colorado Fossils Marine invertebrates have been discovered in a limestone and shale member of the Fountain Formation, cropping out on a low hogback in
Perry Park. Invertebrates include
bryozoans,
brachiopods,
crinoids,
echinoids, and
gastropods. Plant fossils have been discovered in Garden Park north of
Cañon City, including
Lepidophloios laricinus,
Sigillaria,
Syringodendron sp.,
Lepidophyloides sp.,
Lepidostrobus sp.,
Lepidostrobophyllum sp.,
Calamites,
Neuropterus sp.,
Cyclopteris sp., and
Stigmaria ficoides. == Age ==