Layers of Time
To uncover the geologic history of the Florissant region, you must peel back the surface and examine the rock layers below. Sediments are deposited layer upon layer, with the oldest at the bottom and the youngest on top. Because of this principle of superposition, digging downward is like traveling backward in time.
The diagram above represents the rock layers in the Florissant valley. Erosion has revealed these rocks after millions of years of burial. By studying this exposed record of sediment deposition and volcanic activity, we can see how the environment changed over time.
Late Eocene
Florissant Formation 34.07 million years old
[Top to bottom]
Terrace gravels
Deposits of gravel, sand, and soil from weathering of rocks during the last 2 million years
Pumice conglomerate
Airborne volcanic fragments
Upper shale
Fossil-bearing lakebed deposits
Caprock conglomerate
Volcanic debris flow
Middle shale
Fossil-bearing lakebed deposits
You Are Here
Fossil tree stumps preserved in the upper layers of the lower mudstone
Lower mudstone
A series of volcanic mudflows and stream deposits
Lower shale
Fossil-bearing lakebed deposits
Wall Mountain Tuff
A superheated volcanic cloud deposited ash, pumice, crystals, and glass that then compacted and cooled into a welded mass.
Granular granite fragments
Tallahassee Creek conglomerate
Large volcanic boulders
Pikes Peak Granite
This coarse-crystalline reddish granite formed from molten rock cooled deep beneath Earth's surface.
Erected by National Park Service.
Topics. This historical marker is listed in these topic lists: Environment • Paleontology • Parks & Recreational Areas • Science & Medicine.
Location. 38° 54.815′ N, 105° 17.186′ W. Marker is near Florissant, Colorado, in
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Regionally, this marker is in the Colorado High Rockies and in Pikes Peak Region. It is also in the American Mountain West. Globally, it is in North America, the Rocky Mountains, the Western Hemisphere, the Western World, and the Anglosphere.
Other nearby markers. At least 8 other markers are within walking distance of this marker: Just One Piece at a Time (here, next to this marker); Is the Trio in Trouble? (a few steps from this marker); Delicate Impressions (a few steps from this marker); Florissant Valley Today (a few steps from this marker); Ancient Clones (a few steps from this marker); Dawn of the Recent Past (a few steps from this marker); Reading the Rings (a few steps from this marker); Valley Through Time (within shouting distance of this marker). Touch for a list and map of all markers in Florissant.
Also see . . .
1. Florissant Fossil Beds National Monument. (Submitted on October 23, 2020, by William Fischer, Jr. of Reynoldsburg, Ohio.)
2. Eocene Florissant. (Submitted on October 23, 2020, by William Fischer, Jr. of Reynoldsburg, Ohio.)
3. Eocene. (Submitted on October 23, 2020, by William Fischer, Jr. of Reynoldsburg, Ohio.)
4. Geologic History of Florissant. (Submitted on October 23, 2020, by William Fischer, Jr. of Reynoldsburg, Ohio.)
Credits. This page was last revised on October 23, 2020. It was originally submitted on October 23, 2020, by William Fischer, Jr. of Reynoldsburg, Ohio. This page has been viewed 300 times since then and 13 times this year. Photo 1. submitted on October 23, 2020, by William Fischer, Jr. of Reynoldsburg, Ohio.
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