U.S. DEPARTMENT OF THE INTERIORBUREAU OF LAND MANAGEMENT
"Christmas Trees" in Rainbow Basin?
Volunteers Help Barstow BLM with Fossil Resource Management
As you decorate your holiday tree, reflect on the long history of pine and cedar in the southern California deserts. Volunteers recovered 16-million-year-old pine and red cedar remains from Rainbow Basin, the world famous "fossil bed" north of Barstow. This Area of Critical Environmental Concern contains colorful sediments spanning the period between 16.5 and 12.5 million years and define the Barstovian Land Mammal Age of North American. Fossil mammals present include three-toed horses, giant bear dogs, rhinoceros, camels and pronghorns that lived around a shallow lake. Fall field work recovered fossil plants, including pine and red cedar.
Fossils in the Miocene (15 million years ago) Barstow Formation can only be collected under BLM permit, and must be curated into an accredited museum. The Mojave River Valley Museum annually recovers fossils weathering from silty sediments of Rainbow Basin, marking their precise location using GPS coordinates. This project was directed by Mojave River Valley Museum volunteers Robert Reynolds and Bob Hilburn, assisted by members of the Riverside Metropolitan Museum, Inland Geological Society under the supervision of Jim Shearer, Barstow BLM archaeologist.
Articles about the Barstow Formation and its fossils can be found in CSU Fullerton Desert Symposium volumes: 2006 "Making Tracks," and 2010 "Overboard in the Mojave." http://biology.fullerton.edu/dsc/school/symposium.html
- Jim Shearer, Archaeologist, BLM Barstow Field Office (December, 2012)