South Rim, Grand Canyon National Park from near Cameron, Arizona
0.0 Junction of Arizona State Highway 64 with U.S. Highway 89. Arizona State Highway 64 leads west to Grand Canyon National Park. Continue west toward the park. For a description of the geology along U.S. Highway 89, both north towards Cameron and northern Arizona and south towards Flagstaff, see HW-89 Road Guide.. The road here is in the lower part of the reddish Moenkopi Formation.
0.6 Road cuts and resistant sandstone knobs are in the uppermost Shinarump Conglomerate (fig. 1C.1). Shadow Mountain, a tephra cone, is towards the north on the skyline.
Figure 1C.1. View northeastward from Mile 0.6, across Shinarump Conglomerate, towards Ward Terrace and the Painted Desert in Chinle beds.
1.2 Bridge over Tappan Wash. The Tappan Basalt flow (fig. 1C.2) has filled an old channel along the wash. The basalt flowed northward down the ancient Tappan Wash from an unknown source 55 to 65 miles away. The basalt poured into the gorge of Little Colorado River and then flowed westward along that gorge for approximately 9 miles. The flow is the longest individual basalt flow mapped in the San Francisco Peak volcanic field. Tappan Wash here is entrenched into Shinarump Sandstone and underlying Moenkopi beds and through the spectacularly columnar jointed basalt. The road continues to the west across Shinarump Sandstone.
Figure 1C.2. Basalt along Tappan Wash. The Tappan flow poured from the south, a distance of approximately 60 miles, from the San Francisco Peak volcanic field and is the longest individual basalt flow mapped in the field. The recent wash has cut through the columnar jointed basalt.
1.6 Cross beneath power lines from the Glen Canyon Dam to Flagstaff.
2.5 Enter a small-displacement graben, 0.3 miles wide, in the Shinarump Sandstone. Most of the small escarpments for the next several miles are minor fault escarpments which have offset the Shinarump Sandstone or Kaibab Limestone.
4.1 Local hills are covered by residual conglomeratic debris from the Shinarump Conglomerate. Numerous fossil logs occur in Shinarump beds but it is illegal to collect wood here on the Navajo Indian Reservation.
5.7 The road crosses a minor boundary fault. Displacement of approximately 50 feet is expressed by offset of upper beds of the Kaibab Limestone. Moenkopi red beds are downdropped into the small graben. Flatirons of Kaibab Limestone show the strong monoclinal flexure of the Gray Mountain Monocline along the eastern margin of the Coconino Plateau to the south. In some instances the monoclinal flexure is slightly overturned with a fold developed in Moenkopi and Chinle formations. The Gray Mountain Monocline makes a prominent bend at Coconino Point, from almost a north-south trend, to join the Coconino Point Monocline with a nearly east-west trend (fig. 1C.3). The later fold continues westward to where it joins the East Kaibab monoclinal system that extends northward into Utah. The monocline is sharply faulted at the northeastern corner in the East Kaibab Fault zone, with total displacement in excess of 2,000 feet here at the northeast corner. The throw diminishes both to the south and to the west.
7.5 To the south an erratic slab of Kaibab Limestone has apparently slid from the monoclinal flexure down onto synclinally folded Moenkopi and Chinle beds at the base of the monocline. This disturbed area is associated with two circular fault zones developed at the monoclinal margin.
Figure 1C.3. Steeply folded Kaibab and Toroweap beds along the Coconino Point Monocline at approximately Mile 5. Equivalent beds in the foreground are roughly flat-lying, as are the same beds on Coconino Point along the skyline. Steep monoclinal folds are characteristic of the eastern and northern margin of the Coconino Plateau.
10.2 Side Road to Overlook of Little Colorado River Gorge. Little Colorado River here is entrenched in a spectacular gorge approximately 1,000 feet deep (fig. 1C.4). Kaibab Limestone forms the resistant rim rock, above well-bedded Toroweap and massive, tan Coconino Sandstone, which is exposed in the nearly vertical walls of the inner gorge. Far in the distance red mesas of Moenkopi and Shinarump beds rise above the platform held up by the Kaibab Limestone. Shadow Mountain, a relatively large pyroclastic cone, rises above the platform in the distance. The U.S. Geological Survey has established a cable car across the canyon, approximately one-half mile upstream from this point, as a means of gathering flow data on the Little Colorado River. The cable car is not open to the public.
Figure 1C.4. View upstream from the Little Colorado River Overlook along the gorge carved into the Marble Platform. The rim rock is Kaibab Limestone, but rocks as old as Coconino Sandstone are exposed in the lower part of the gorge. Boundary faults of some of the small grabens offset Kaibab Limestone along the canyon rim, in the background of the inner gorge. Shadow or Ghost Mountain, a volcanic cone, is the dark rounded hill on the horizon, in the distance.
11.7 To the south the isolated ridge in front of the major escarpment is a fault block, set off from the main monoclinal flexure. The road here is over Moenkopi red beds which are capped by varying thicknesses of Pleistocene pediment gravel. The Moenkopi beds near the highway dip gently toward the north but a few hundred yards south of the highway Moenkopi beds are vertical to overturned along the Coconino Point monoclinal flexure.
13.0 Small grabens in front of the Gray Mountain Monocline are well displayed toward the north.
13.8 Exposures in a small graben, which here has broken Kaibab and Moenkopi beds north of the Coconino Point Monocline. For the next several miles road cuts are in the Moenkopi Formation, with varying dips toward the north.
14.4 Cattle guard, junction of new segment of road with old highway. Moenkopi beds are exposed in road cuts and are somewhat faulted and slumped along the margin of the Coconino Point Monocline. Moenkopi beds show mud cracks and extensive ripple marks, some of which show two directions of transport, like on a tidal flat.
14.7 Nearly flat Moenkopi beds are exposed along the highway (fig. 1C.5) but approximately 100 yards to the south, these same beds are dipping steeply northward off the monocline.
Figure 1C.5. Gently folded Moenkopi beds exposed in road cuts at approximately Mile 15.5. These red Moenkopi rocks are overlain by light-colored, poorly consolidated gravel which veneers a pediment cut at the base of the Coconino Point Monocline.
15.8 View Point to the north looks over the deeply entrenched Little Colorado River which has cut a vertical-walled gorge into the Marble Platform (fig. 1C.6). Brick red Moenkopi beds are exposed in road cuts. All the slopes are thickly veneered with weakly cemented gravel, deposited over a cut pediment surface.
16.3 Steeply dipping fins of Kaibab and Coconino formations (fig. 1C.7) are visible in the V-shaped gorges to the west.
17.7 Steeply dipping Kaibab Limestone is exposed in deep road cuts and many surfaces show slickensides (fig. 1C.8), both on bedding planes and on joints. Breccia indicates the relative brittle nature of the limestone beds. To the northwest the prominent rise is along the East Kaibab Monocline. Farther to the west this north-south trending fold terminates against the Coconino Point-Grand View Monocline in an area of minor faulting and general structural confusion.
Figure 1C.6. View toward the north, from approximately Mile 15.8, of the gorge of the Little Colorado River cut into the nearly flat-lying Kaibab Limestone of the Marble Platform. Rocks in the foreground are near the base of the Coconino Point Monocline and beds beyond are essentially horizontal.
Figure 1C.8. Prominent slickensides along faults in steeply dipping Kaibab Limestone at Mile 17.7.
Figure 1C.7. Vertical to overturned Kaibab and Toroweap limestone exposed along the base of the Coconino Point Monocline, south of the highway at approximately Mile 16.5. Kaibab rocks on the skyline are nearly flat and rocks in the foreground are only gently dipping away from the monoclinal flexure.
18.1 Deep fill over tributary canyon.
19.0 Deep double road cuts through nearly horizontal Kaibab Limestone, here broken by minor faults and breccia zones.
19.6 We have now climbed onto the upper part of the East Kaibab Monocline, on Kaibab beds. To the south a minor monoclinal flexure continues toward the west as the Grand View Monocline (fig. 1C.9), west of where the Coconino Point fold was intersected by the East Kaibab Monocline.
20.1 Enter Kaibab National Forest and Leave the Navajo Indian Reservation.
22.2 Kaibab Limestone exposed in all directions along the monoclinal flexure. To the west the surfaces are a stripped Kaibab surface where easily eroded Moenkopi beds have been removed. Grand View lookout tower is to the south on the crest of the monocline.
22.5 Bridge across Lee Canyon. The Upper Basin, through which we are now passing, is forested with pinion and Ponderosa pine. Toward the south the Grand View Monocline is visible with steadily diminishing throw along the fold toward the west.
Figure 1C.9. Grand View Monocline forms the abrupt escarpment separating the Upper Basin sequence, in the foreground, from the high part of the Coconino Plateau, in the background. Both surfaces are held up by essentially the same stratigraphic units near the top of the Kaibab Limestone. The limestone is upflexed sharply along the escarpment.
28.7 Leave Kaibab National Forest and Enter Grand Canyon National Park (fig. 1C.10). The road continues approximately parallel to Deer Tank Wash and crosses the upper stripped surface of the Kaibab Limestone.
30.5 San Francisco Peaks are now visible beyond the escarpment to the south. The high point, Humphreys Peak, has an elevation of 12,670 feet.
31.6 Slow, Park Service Checking Station.
31.7 Junction of Access Roads to the North to the Parking Area at Desert View. The view point provides a panoramic view over the monocline along the east side of the plateau, as well as the Painted Desert and Marble Platform to the east, and the eastern end of Grand Canyon. The watchtower (fig. 1C.11) was built in 1932 by the Santa Fe Railroad and Fred Harvey, a concessionaire in the park. It is a representation of prehistoric Indian watchtower and is not a replica or restoration of any one individual tower.
The Colorado River is visible in the lower regions of the canyon where it cuts through the upper Precambrian bedded sequence (fig. 1C.12). The latter beds are cut by a variety of sills and dikes of Precambrian diabase. Precambrian rocks are overlain by the Cambrian through Permian sequence, with Kaibab Limestone forming the rim. The canyon here is a little over 4,500 feet deep. Tanner Canyon drains the slopes toward the north, east of Cardenas Butte and west of the prominent cliffs of the Palisades of the Desert. The Kaibab Limestone forms the canyon rim in the Palisades of the Desert area on the downdropped or downfolded side of the East Kaibab Monocline. Desert View area is on the upflexed part of the fold. The reddish Precambrian Dox Group forms exposures along the canyon bottom. These and slightly younger Precambrian rocks are overlain with marked angularity by the Tapeats Sandstone, the basal unit of the Paleozoic sequence above the "Great Unconformity."
In the distance, approximately three miles to the east, Cedar Mountain is capped by Shinarump Conglomerate above Moenkopi red beds. Cedar Mountain is an outlier of the Moenkopi-Shinarump sequence. These beds have been stripped from most of the Marble Platform.
Figure 1C.10. Index map to some of the prominent features in Grand Canyon National Park. The route into the Park leads along Arizona State Highway 64, from the southeast, toward Desert View and the East Rim Drive along the south margin of Grand Canyon (modified from National Park Service Information).
Figure 1C.11. The Watch Tower at Desert View, at the southeast margin of Grand Canyon. The Watch Tower is a generalized reproduction of Indian watchtowers and is not a restoration of any individual tower.
Figure 1C.12. View north from the Desert View Lookout into the upper part of Grand Canyon. Palisades of the Desert and the Facade of the Desert are along the eastern margin of the canyon, in Kaibab Limestone and underlying rocks. Dark units near the canyon bottom are Precambrian lava flows and intrusions which underlie the Paleozoic sequence that forms the ledges and slopes above the broad inner gorge. The Vermilion Cliffs are on the skyline in the far distance, beyond the inner gorge, and the Echo Cliffs are along the skyline toward the right.
32.6 Navajo Point on the northwest, elevation 7,498 feet. The Colorado River in the bottom of the gorge is at approximately 2,700 feet.
33.5 Roadside exposures of cherty Kaibab Limestone.
32.5 Side Road North Toward Lipan Point (0.5 miles). Lipan Point provides a panoramic view of the eastern end of the Grand Canyon, from the deeply entrenched V-shaped inner gorge in the west where the Colorado River has notched below the Tonto Platform and exposed the Vishnu Schist (fig. 1C.14), eastward to the broad open canyon bottom carved on the Grand Canyon series, as at Unkar Rapids north of Lipan Point. Palisades of the Desert and the rim of the Marble Platform are visible in the distance to the northeast. The entire stratigraphic sequence from Vishnu Schist and Dox Group up through the upper Precambrian sequence is exposed in north eastward tilted beds beneath the Great Unconformity at the base of the Cambrian Tapeats Sandstone. The prominent cliff of Redwall Limestone rises above the shelf cut on the Bright Angel Shale, and below the ledge-and-slope zone of the Supai Sandstone. Coconino Sandstone rises as a light cliff in the upper reaches of the canyon walls and is capped by the cliff-forming, rim-forming Kaibab Limestone along both walls of Grand Canyon.
Figure 1C.13. View north from Lipan Point, across Unkar Rapids along the Colorado River, to Cape Royal and the Walhalla Plateau along the North Rim. Unkar Creek enters at Unkar Rapids in the light-colored delta along the Colorado River. The prominent angular unconformity between the Precambrian Grand Canyon series and the overlying Cambrian Tapeats Sandstone show very well in the bluffs in front of Apollo Temple and Venus Temple, in the right center. The canyon here is approximately 8 miles wide and 4,500 feet deep.
33.0 View point on the left.
33.8 Side Road to the South Leads to Tusayan Ruins and Wayside Museum of Archeology (0.2 miles). The museum is generally open for the summer tourist season, from Memorial Day to Labor Day. The museum exhibits the cultures of the Basketmaker, Cohonina, and Pueblo Indians that occupied the canyon area and the plateau. Pueblo-type Indians built the Tusayan structures about 1185 A.D.
Figure 1C.14. View toward the west from Lipan Point toward Yavapai Point, in the distance. The Colorado River here is entrenched in the inner gorge, below the Tonto Platform and the cliff formed by the Tapeats Sandstone. Seventy-five Mile Creek is the canyon in the foreground. Hance Rapids is along the inner gorge, where the Colorado River is visible through the notch.
34.2 Road cut in the poorly exposed Kaibab Limestone, here, with a thin veneer of soil in the Ponderosa pine forest.
36.0 Picnic area on the south.
37.1 Kaibab Limestone is dipping to the northeast off the Grand View Monocline, which is to the south and the southwest. The monocline here has a structural relief of 300 feet to 400 feet.
37.6 Road to the North Leads to Moran Point (0.2 miles) which offers an additional panoramic view of the central part of the Grand Canyon. Moran Point is on the Kaibab Limestone Plateau, between the Grand View Monocline of the Coconino Rim and the East Kaibab Monocline at the east edge of the park. The view down Red Canyon is to Hance Rapids on the Colorado River, beneath the resistant Shinumo Quart-zite, at the beginning of the V-shaped, deep inner gorge of the Grand Canyon of the Colorado River.
39.4 Roadside view point of the Sinking Ship, an erosional remnant of the Kaibab Limestone tilted eastward along the Grand View Monocline (fig. I C.15).
Figure 1C.15. View westward to the Sinking Ship, an erosional remnant of east-dipping Kaibab Limestone which has been flexed up along the Grand View Monocline, where that fold crosses the South Rim.
40.6 The highway is now ascending the Grand View Monocline on Buggeln Hill and rising from the Coconino Plateau lower surface up to the upper surface still in Kaibab Limestone. Kaibab exposures have an elevation of approximately 7,000 feet at the base of the hill and 7,400 feet at the crest of the hill, at the top of the monocline.
43.6 Side Road to the North to Grand View Point (0.7 miles). Grand View Point offers a magnificent panorama of the eastern and western parts of the Grand Canyon because the Colorado River changes direction from a southwesterly flow and starts to flow toward the northwest through the central part of the park, about opposite Grand View Point.
The old Last Chance copper mine is on Horseshoe Mesa, approximately 2,500 feet below the rim of the canyon. The Last Chance Mine is in Redwall Limestone and produced a minimal amount of ore in the late 1800s early 1900s. The ore was hauled by mules up the Grand View trail to Grand View Point. The trail is no longer maintained by the park service so those individuals interested in hiking down into the canyon along the Grand View trail must register with the park service.
Horseshoe Mesa is capped by an outlier of Supai Formation, above the Mississippian Redwall Limestone. Vishnu Schist is exposed in the V-shaped inner gorge of the Grand Canyon, below the ledge-forming Bass Limestone visible through the notch of Hance Creek. Red Hakatai Shale is overlain with angular unconformity by the Tapeats Sandstone at the upper edge of the inner gorge, but pinches out against a Precambrian island on Shinumo Quartzite. Directly across the Colorado River, down Hance Creek, Bright Angel Shale rests unconformably across the older Precambrian rocks and Tapeats Sandstone laps out against the buried Shinumo cuesta. To the east in Palisades of the Desert, Coconino, Toroweap and Kaibab formations make up the canyon rim, above the relatively broad, open, amphitheaterlike valley carved on reddish upper Precambrian beds.
45.8 Roadside view point on the north.
47.6 Roadside view point. On the left is one of the tributaries at the head of Grapevine Creek.
48.4 "Duck On Rock" view point. The Vishnu Fault is along the trend of Grapevine Creek and crosses the rim of the canyon at approximately this point. This area provides a panoramic view of the north rim of the canyon, particularly to Cape Royal, and eastward to Desert View on the south rim at the east end of the park. The Echo Cliffs rise above the Marble Platform on the skyline in the far distance to the east.
51.2 Junction of Side Road to the North Leads to Yaki Point and head of Kaibab trail (fig. IC.16). Kaibab trail winds down the south rim of the Grand Canyon to the suspension bridge, a distance of 6.5 miles, and continues to the north side of the river up Bright Angel Creek to Phantom Ranch (7.3 miles) and connects to the trail down from the north rim, with a total trail distance of 20.6 miles.
52.3 Junction of East Rim Drive with the South Entrance Road. Exit toward the south to Williams along U.S. Highway 180 or continue toward the north toward Grand Canyon Village, along the East Rim Drive.
53.0 Mather Point on the North (fig. 1 C.17).
53.6 Road to the North to Yavapai Museum and Yavapai Point (0.2 miles). A large section of Granite Gorge is visible from Yavapai Point where the Colorado River has cut through Brahma Schist beneath the Tonto Platform. Toward the north Phantom Ranch is visible along the lower stretch of Bright Angel Canyon and the suspension bridge over the Colorado River is visible to the east of the mouth of Bright Angel Creek, in the deep notch of Granite Gorge. The Bass Limestone overlies the Vishnu beds beneath the Tonto Platform and the Great Unconformity. Pink Zoroaster Granite cuts Brahma Schist at the mouth of Clearcreek and Zoroaster Creek to the northeast.
54.4 Visitor Center, Grand Canyon National Park on the Northwest. The trailer park and the campground arc to the southeast through the Ponderosa pine forest.
5.4 Main Intersection in the Lodge Area. Junction of the East Rim and West Rim Drives and roads to the campground areas to the south. Continue westward past the El Tovar Lodge and the railroad station on the West Rim Drive.
Figure 1C.17. View north to Bright Angel Creek and the North Rim from Mather Point. The inner gorge, along Phantom Creek and the main Colorado River, is carved in Brahma Schist. The upper edge of the inner gorge is outlined by cliffs of Tapeats Sandstone and, locally, by an island in the Cambrian Sea of the Shinumo Quartzite. The slope zone above is the Tonto Platform, carved on the Bright Angel Shale. The first prominent cliff above the Tonto Platform is Mauv and Redwall Limestones. The light-colored, prominent, cliff near the skyline, in the distance, is the Coconino Sandstone, beneath the Kaibab Limestone, which is exposed along the skyline at the crest of the Kaibab Plateau.
Figure 1C.18. View northwestward from Yavapai Point toward the inner gorge and Tonto Platform, in the region north of the Grand Canyon village area. Light-colored granite dikes cut the Brahma Schist, the Precambrian rocks exposed in the inner gorge beneath the flat-lying Tapeats Sandstone of Cambrian age. Other Paleozoic rocks are also exposed, up to the Kaibab Limestone which forms the rim and crest of the Kaibab Plateau, along the north side of Grand Canyon.
Figure 1C.19. View northward from Maricopa Point toward the North Rim. Bright Angel Creek cuts the deep gorge toward the right, beyond the trail in the foreground that leads to Plateau Point. Precambrian Bass Limestone occurs above the vertical Brahma Schist, and below the slope-forming Haktai Shale on the north part of the inner gorge. An island of Shinumo Quartzite (arrow) rises above the Cambrian Tapeats Sandstone, which laps out against the "island", both on the east and the west. Bright Angel Shale forms the broad platform below the prominent cliffs of Redwall Limestone, at middle distance up the canyon rim.
5.9 Parking Area at the Head of Bright Angel Trail View Point. Junction of sideroad to the motor lodge to the south with the West Rim Drive. Continue westward on the West Rim Drive.
57.1 View point looks over the Bright Angel Trail and the lodge area on the point to the east.
57.4 Viewpoint overlooking the trail area to the east.
57.6 Parking area at Maricopa Point. Vertical Brahama Schist, with dikes of Zoroaster Granite, shows well in the V-shaped inner gorge, beneath the Tonto Platform. The hoist frame for the old mine is just to the west of the point.
8.1 Powell Memorial parking area on the east side of the highway.
58.2 Junction Side Road. Hopi Point on the north (0.1 mile). Vertical Vishnu Schist and Zoroaster Granite dikes are well exposed in the inner gorge.
Figure 1C.20. View westward from Pima Point along the inner gorge in the western part of Grand Canyon. The V-shaped inner gorge is here cut in Vishnu Schist, beneath the cliff-forming Tapeats Sandstone. Boucher Rapids occur along the Colorado River at about the major bend. The first prominent cliff above the inner gorge and the Tonto Platform slope is held up by the Redwall Limestone.
58.9 Junction of Side Road to Mojave Point (0.15 miles). Mojave Point provides an excellent view of the western end of the canyon as well as one down into the V-shaped notch of the inner gorge cut in Vishnu Schist. The west rim road huddles close to the edge of the escarpment and provides numerous viewpoints into the canyon.
62.0 Junction Side Road to Pima Point (0.3 miles), which provides additional views of the inner gorge and rapids in the western part of the Grand Canyon (fig. 1C.20).
62.8 Turnaround Loop Road at Hermits Rest at the west end of the West Rim Drive.
from Field Guide: Northern Colorado Plateau by J. Keith Rigby - Purchase Information
