Conor Watkins And J. David Rogers
Grand Canyon Research
Tapeats Cave Canyon



Tapeats Cave Canyon is located in Tapeats Amphitheater and contains Tapeats Spring, which provides the majority of the water in Tapeats Creek.  Huntoon (1970) estimated that Tapeats Spring discharges about 48 million gallons of water per day (mgd), making it the largest spring on the north side of the Grand Canyon.  Thunder River Spring is the second largest spring on the north side, discharging about 21 mgd.  These two springs feed into Tapeats Creek.  The Tapeats Fault provides structural control of the cave, the spring, and likely played a pivotal role in the triggering of the landslides.  This interrelation between faults, springs and landslides is apparent elsewhere in the Grand Canyon.


Overview of Tapeats Ampitheater and Tapeats Cave Canyon areas from Monument Point on the north rim of Grand Canyon.


This portion of the USGS 7.5" Tapeats Amphitheater topographic map has been annotated to show areas of landsliding we are mapping in and around Tapeats Cave Canyon.


Portion of "Geologic Map of the Grand Canyon 30' x 60' Quadrangle, Coconino and Mohave Counties, Northwestern Arizona" published by the USGS in 2000.  This map is of insufficient detail to show the smaller slides that mantle the lower slopes in Tapeats Cave Canyon, which floor in the Bright Angel Shale.


Ground view of Tapeats Cave Canyon looking at the fault-controlled notch in the Esplanade. This view is looking upstream towards Tapeats Spring, which lies below and to the right of the prominent notch, along a splay of the Tapeats Fault.


The Tapeats Spring branch of Tapeats Creek is typified by picturesque waterfalls and choked with coarse debris, indicative of a channel out of equilibrium.  The channel profile exhibits classic signs of modest hydraulic choking over a considerable distance.


The profile of Tapeats Spring branch exhibits evidence of modest debris choking, as shown in this diagram. The landslides impacting the channel are relatively small in comparison to those in the Surprise Valley, Deer Creek, Cranberry and Fishtail watersheds.  Another factor may be the nearly 50 million gallons of water per day that flows out of Tapeats Spring, which provides considerable stream power to erode blockages.


This view shows the jumbled landslide debris mantling most of the exposed slopes in Tapeats Cave Canyon.  The Tapeats Fault is a normal fault with the western side dropping relative to the east.


Closer view of the Tapeats Fault splay and the hanging valley.  The main fault (left) and the splay controlling Tapeats Spring (right) are shown in red.


This Toreva block near Tapeats Spring has blocked the natural outlet of the spring, causing water to percolate through the debris as a series of pools and waterfalls in lieu of a discrete discharge, like Thunder River.  The basal failure surface appears to be developed in the Bright Angel Shale, which has been shown to lose significant strength when saturated.  All of the large springs and many of the smaller ones in this part of the Grand Canyon are surrounded by landslides.


The back rotated blocks on the eastern side of Tapeats Cave Canyon are larger and more numerous than those on the opposite wall.  This may be ascribable to increased pore water pressures being developed on the foot wall side (east) of the fault due to secondary fracturing and/or perching of water by fault gouge. The area east side of the fault is also at a higher elevation and receives larger amounts of precipitation than areas just to the west, so a larger amount of groundwater likely percolates through the eastern wall of the canyon.


Conor standing in one of the pools below Tapeats Spring.  The springs appear as water coming out of the ground in a series of small waterfalls and pools.  This is because water is percolating through landslide debris that blocks the spring's pre-slide outlet. 


Garrett Euler and Mike McEuen enjoy one of the pools at Tapeats Spring.


Indurated sediments mantle the Bright Angel slope in much of Tapeats Cave Canyon.  Some of these are coarsely stratified parallel to the slope and appear to be talus accumulations.  Others, which tend to be horizontally stratified and more fine-grained, appear to be lacustine sediments mixed with debris flow packages that were likely deposited in temporary reservoirs caught behind landslide dams.  Based on the depths and vertical extent of these lacustrine materials, we can deduce that significant portions of much larger landslide dams have been excavated by discharge from Tapeats Spring.

Prmoninences of rock, which appear to be an incipient form of mass wastage, appear in addition to the landslides mantling the slopes in Tapeats Cave Canyon. The prominences, composed of the Redwall, Muav, and Bright Angel Formations, appear to be slowly separating from the canyon walls along nearly vertical planes as the underlying Bright Angel Shale strains. These prominences are most noticeable along the east wall of Tapeats Cave Canyon of the largest of these features is present along the north side of Tapeats Creek, just west of the mouth of Tapeats Cave Canyon. These features were identified using aerial photos and appear to be a form of stress relief described in the Grand Canyon in Huntoon (1973) known as high-angle gravity faulting.  It is likely that the existing adjacent landslides serve to confine and buttress these formations and keep them from failing completely. It is possible these features will evolve into landslides sometime in the future when the existing landslide materials are removed by erosion.


Prominences of rock appear to be separating along vertical fractures on the east side of Tapeats Cave Canyon and along the north side of Tapeats Canyon west (left) of Tapeats Cave Canyon (indicated by red arrows) due to straining of the underlying Bright Angel Shale.  (Photo courtesy of Alan Herring)


Mouth of Tapeats Cave, which is controlled by a splay of the Tapeats fault.  The cave entrance is slightly higher and just east of Tapeats Spring.  This smaller passage eventually joins the main trace of the Tapeats Fault, where an underground river supplies the spring discharge.


The outlines Garrett Euler and Mike McEuen provide an idea of scale at the opening of Tapeats Cave. The entrance is nearly 20 feet tall.


View of fault-controlled passages inside the cave, developed in the Muav Limestone.  The fault easily traced in the ceiling of the cave.


Garrett Euler investigates Tapeats Cave.


Mike McEuen investigates the narrow entrance passage of Tapeats Cave , which is fault controlled.  Ceiling collapses (breakdown) are common in this reach. 


Mike McEuen standing in the a large room where the entrance passage joins the main part of the cave.

 
Upon entering the main passage of Tapeats Cave, the rooms take on much larger dimensions and water is seen for the first time.  This water feeds Tapeats Spring.


Mike and Garrett stand in a narrow passage of Tapeats Cave. According to Peter Huntoon's 1970 PhD dissertation, there is around one mile of underground passage in Tapeats Cave.

Questions or comments on this page?
E-mail Dr. J David Rogers at rogersda@umr.edu
or Conor Watkins at cwatkin@umr.edu.