Fossil Plants from the Denver Basin, D1 Section (approx. 64 mya)
(East of Colorado Springs, CO, April 2003)

Reporter from The Gazette (Colorado Springs) 
interviews Rich Barclay (DMNS), 4/22/03.

Large seed, possibly of the walnut family (4/22/03)

Note the red/orange color of this seed, all others found
here are tan/beige. This seed also had a porous structure
in its center. (4/23/03)

The day gives way to the snow on 4/23/03

The Denver Museum of Nature & Science (DMNS) & its "Fossil Posse" are working on another fossil plant locality as part of the Denver Basin Project.  This site, termed "Chopping at the Gap", is east of Colorado Springs.  It is believed to be in the D1 strata of the Denver Basin - beginning approx. 68 MYA and ending about 64 MYA (million years ago).

The D1 & D2 sections are separated by the paleosol layer (a brightly-colored interval marking an unconformity in the stratigraphic record. The red, orange & sometimes purple paleosol consists of mudrocks that show morphologic features indicating ancient soil development [2].  This paleosol layer has yet to be found near "Chopping at the Gap".  However, it's believed to be somewhere between the quarry (foreground at left) and the line of pine trees (background at left) at the Black Forest.  The pine trees prefer the soil mix of the D2 layer because of its looser, more coarse material and better drainage.

The fossil layer at "Chopping at the Gap" is approximately 0.5 meters thick.  It's believed to be a crevasse-splay (see "Meandering River") because of its mat layer of horizontal leaves at the bottom and mix of fine sandstone & imperfect horizontal leaves just above the mat.

Until further excavation is done at this site, its exact locality cannot be revealed.  The property belongs to El Paso County. The roadcut is an El Paso County Dept of Transportation right-of-way. There is no public access at this site.

The image at left shows large seeds, believed to be from the walnut family, found at the quarry.

Unidentified leaf


Note: This locality has been designated as DMNS #2687.


1. The "Fossil Posse" is a group of staff and volunteers at the Denver Museum of Nature & Science (DMNS) specifically organized to respond rapidly to fossil discoveries.  For more on the Fossil Posse, CLICK HERE.
2. "The stratigraphic and climatic significance of Paleogene alluvial paleosols in synorogenic strata of the Denver Basin, Colorado.", Timothy M. Farnham and Mary J. Kraus, 2002.
[Created 4/24/2003]
[Last Updated: 5/02/2003]