Sunday, March 13, 2011

Florissant Fossil Beds

In the western foothills of the Pike's Peak massif, petrified stumps and logs of giant sequoias lie amidst groves of ponderosa pine and outcrops of Precambrian granite. Protected within the Florissant Fossil Beds National Monument since 1969, these fossilized trees are the highlight of one of the more complete time capsules of an Oligocene ecosystem on our planet.

About 35 million years ago, volcanic eruptions in the Thirty Nine Mile Range, southwest of Florissant, Colorado, sent ash clouds and mudflows across this region, quickly burying and preserving a diverse collection of plant and animal life. Fossils of these organisms are now encased in shales, mudstones, silstones and volcanic tuff, some of which settled in Lake Florissant, created by the mud flows.

The fossil beds of this National Monument are especially famous for the fragile impressions of insects, spiders and leaves that were captured within the volcanic deposits. Access to the Monument and its 14 miles of hiking trails is via a road that leads south from Florissant, which is on U.S. 24, 35 miles west of Colorado Springs; a day-use fee is charged to enter the preserve, which is open every day except for major holidays.