Canyon de Chelly National Monument
by Christina Gaudette & Kristy Fredericks
Canyon de Chelly National Monument is located within the Navajo Reservation in the northeastern Arizona region of the Colorado Plateau. The Monument includes Canyon del Muerto, Monument Canyon, and Canyon de Chelly. Our visit was to Canyon de Chelly, which included taking the 1.5 mile hike down the White House Ruins Trail into the canyon.
The dominant geologic feature in Canyon de Chelly is the Lower Permian De Chelly Sandstone. The De Chelly Sandstone is an aeolian sandstone with observable large-scale tangential cross stratification. The aeolian features observed in the canyon strongly support the inference that the paleoenvironment was that of a large erg (sand sea) that expanded episodically (Stanesco, 1991). Located above the De Chelly Sandstone is the Upper Triassic Shinarump Member of the Chinle Formation. The Shinarump is a coarse grained conglomerate that is mostly lenticular (Craigg, 2001). A vertical contact between the De Chelly Sandstone and Shinarump Member can be observed on the canyon wall towards the top of the White House Ruins Trail (pictured above). The contact is an unconformity that represents an erosion surface on the De Chelly Sandstone that was then overlain by the Shinarump Member (Stanesco, 1991).
While hiking into the canyon, keep a look out for the “rock hammer” (pictured left) naturally carved high up on the canyon wall!
“Proof that geology is the chosen profession”
Inside the Canyon are the White House Ruins (pictured above). The ruins are the preserved remains of the Anasazi cliff dwellings. The Anasazi people were the early inhabitants of the Four Corners Region. Tree ring dating suggests the lower ruin of the White House was constructed during the mid-eleventh century (Grant, 1978).
“Out of all the Canyons we had visited on the trip, I found Canyon de Chelly to be the most beautiful. The way the sun hits the steep sandstone walls and shines down on the stream and vegetation on the canyon floor is a site like no other. It was amazing to be in the Canyon and realize that there are still local Navajo people that live inside this gorgeous, isolated place.” – Christina Gaudette
“Our visit to Canyon de Chelly was at the end of our trip, so it was a welcome, non-strenuous, break. By this point, we had seen a lot of aeolian sandstones, so my interest was not in the geology but more in the White House Ruins and the locals. It was great to talk to the local Navajo people that lived in the Canyon and purchase some of the jewelry they had crafted.” – Kristy Fredericks
Craigg, S.D., 2001, Geologic framework of the San Juan Structural Basin of New Mexico, Colorado, Arizona, and Utah, with emphasis on Triassic through Tertiary rocks: Reston, VA, U.S. Dept. of the Interior, U.S. Geological Survey: Denver, CO, Branch of Information Services, 70p.
Grant, C., 1978, Canyon de Chelly: Its people and rock art: Tucson, University of Arizona Press, 290p.
Stanesco, J.D., 1991, Sedimentology and Cyclicity in the Lower Permian De Chelly Sandstone on the Defiance Plateau: Eastern Arizona: The Mountain Geologist, v. 28 (4), p. 1-11.