Falls Trail Stop 1
NPS Photo by Stella Carroll
The pinkish colored rocks on the slopes and in the cliffs above you are volcanic tuff. About 1.6 and again 1.2 million years ago, there was a tremendous series of volcanic eruptions (600 times larger than the blast from Mount St. Helens in 1980) from the Jemez (HAY-mez) Mountains just northwest of here. Ash from the explosions was deposited across the nearby landscape in thick layers creating the Pajarito (Pah-ha-REE-toe) Plateau. Some ash was carried on the prevailing winds forming thin deposits as far away as Iowa. Looking closely at the tuff, a sandy texture is apparent. Volcanic tuff here is porous and relatively soft. Running water erodes it quickly, cutting deep, steep-walled canyons like this one.
Did You Know?
Frijoles Creek drops approximately 80 feet over the Upper Falls. The falls occur where the waters of Frijoles Creek hit the more resistant, dense basalt rock from the neck of an ancient volcano.