© 2019 Corral Bluffs Alliance

All photographs copyright S. Milito, Corral Bluffs Alliance; HHMI Tangled Bank Studios; Bill Koerner, Corral Bluffs Alliance; Cody Sutton, City of Colorado Springs Parks

Geology and Paleontology of Corral Bluffs

Corral Bluffs and Jimmy Camp are important because the rocks tell the story of dinosaurs, the extinction of 75% of life on Earth and its subsequent recovery leading to the origin of our modern world . The Denver Museum of Nature & Science has been conducting research concerning the ancient environment surrounding the K-Pg (K-T) boundary in Corral Bluffs and Jimmy Camp since 1991. The University of Colorado, Colorado College, University of New Hampshire and The Smithsonian Institution have also conducted research here.

The rocks of Corral  Bluffs were deposited as the Rocky Mountains were uplifting and simultaneously eroding, rivers and flood waters carrying off the debris. During that process exquisite fossil skulls of rare mammals were preserved in hard rock packages called concretions. 

 

At that time, 66 million years ago, Corral Bluffs was barely above sea level; the climate was subtropical, similar to that in Florida today. Evidence for this climate is found in leaf and tree fossils, as well as fossils of turtles and crocodiles.

Over 1,000 vertebrate fossils, 6,000 leaf fossils and 37,000 fossil pollen grains from Corral Bluffs have been collected and analyzed by Dr. Tyler Lyson and Dr. Ian Miller of DMNS and their colleagues to reveal the ecosystem, temperature, climate and location of the K-Pg boundary.

For detailed information on recent fossil discoveries at Corral Bluffs please see our NEWS page

 

An over head shot of the prepared mammal skull fossils and lower jaw retrieved from Corral Bluffs.

HHMI Tangled Bank Studios.

CGI rendering of ancient Loxolophus mammal taken from the PBS NOVA special, Rise of the Mammals. In this recreation, Loxolophus scavenges for food in the palm dominated forests found within the first 300,000 years after the dinosaur extinction.

HHMI Tangled Bank Studios

CGI rendering of ancient Carsioptychus mammal taken from the PBS NOVA special, Rise of the Mammals. In this recreation, Carsioptychus coarcatus eats plants in a newly diversified forest, about 300,000 years after the mass extinction that wiped out the dinosaurs

HHMI Tangled Bank Studios

An overhead shot of selected plant fossils retrieved from Corral Bluffs. More than 6,000 leaves were collected as part of the study to help determine how and when Earth's forest rebounded after the mass extinction event.

HHMI Tangled Bank Studios

A cranium of a new species of Loxolophus  uncovered at the Corral Bluffs fossil site.

HHMI Tangled Bank Studios

A cranium of a Carsioptychus, uncovered at the Corral Bluffs fossil site.

HHMI Tangled Bank Studios

CGI rendering of ancient Taeniolabis mammal taken from the PBS NOVA special, Rise of the Mammals. HHMI Tangled Bank Studios

Denver Museum of Nature & Science age model for the rocks of the D1 sequence in the Denver Basin [Raynolds RG, Johnson KR, Dechesne M, Miller IM (2017) Earth History along Colorado’s Front Range: Salvaging geologic data in the suburbs and sharing it with the citizens. GSA Today: Vol. 17, No. 12 pp. 4-10]

If you were to dig a hole 3 miles deep straight down through Colorado Springs these are the rock formations you would find. Or, you could visit these formations at local parks and open spaces!

Stratigraphic Section adapted from Geologic Portfolio of Red Rock Canyon Open Space, Weissenburger, Milito, Ellis. 2010

Download Colorado Springs Stratigraphic Section

A cranium of a Taeniolabis taoensis uncovered at Corral Bluffs fossil site. Taeniolabis appears approximately 700,000 years after the KT extinction, is a herbivore, and appears at the same time as the world's oldest legume plant fossil.

HHMI Tangled Bank Studios.

Corral Bluffs is at the southern end of the Denver Basin. Looking down from space, or seen from the side in a cross-section, the strata of the Denver Basin would resemble a sliced onion, each layer a different rock formation from a different geologic time period and environment. 

 

       Strata of Corral Bluffs

The Cretaceous/Paleogene sandstone and mudstone of Corral Bluffs and Jimmy Camp are a part of the D-1 Sequence of the Denver Formation.

 

West-east cross section “showing the distribution of synorogenic deposits in the unconformity-bounded D1 and D2 sequences, Denver Basin, Colorado... Modified from Raynolds (1997).”

[Roberts SB (2004) Coal in the Front Range Urban Corridor--An Overview of Coal Geology, Coal Production, and Coal-bed Methane Potential in Selected Areas of the Denver Basin, Colorado, and the Potential Effects of Historical Coal Mining on Development and Land-use Planning, Chapter F (p. 117-162) in Fishman, N.S., ed., Energy Resource Studies, Northern Front Range, Colorado, U.S. Geological Survey Professional Paper PP-1698.]