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Bright Angel Fault
Looking across the canyon, you can see evidence of a fracture in the earth, the Bright Angel Fault. Stretching across Grand Canyon in front of you, Bright Angel Canyon traces the route of the Bright Angel Fault.
Faults are fractures in the earth's crust along which movement occurs. Rarely can you see a fault, but you can see evidence of it. Evidence can be seen here in the displacement on either side of the fault.
On the opposite cliff, an offset in the rock layers -- best seen in the light-colored Coconino Sandstone -- demonstrates the shift. The layers on the right of the fault rise about 150 feet (50 meters) higher than on the left.
Bright Angel Fault is still active, producing small earthquakes which visitors sometimes feel.
Two major trails follow the trace of the Bright Angel Fault (photo below left). Side canyons, which tend to form along fault lines, become convenient routes for
access into the Grand Canyon. The North Kaibab Trail follows the fault trace on this side of the canyon; the Bright Angel Trail follows it on the other.
Most of the faults which criss-cross the Grand Canyon region (map below) are far older than the canyon itself. Movement along a fault creates a zone of weakness which becomes a channel for erosion (illustration below). Many of Grand Canyon's spectacular side canyons -- like Bright Angel Canyon -- have formed through erosion along zones of weakness which follow major north/south fault. |