LUPTON TO ST. MICHAELS
NAVAJO 12
This pleasant drive, only about twenty miles west of Gallup, presents an interesting change of scenery. The highway travels through hogbacks eroded into the upturned strata along the eastern limb of The Defiance Monocline and into a ponderosa forest before returning to the flats. The Uplift is as much as 35 miles wide and runs about 90 miles from Lupton to near the San Juan River on the north. Interpretation of the geology of this area is a focal point for geologists from four different states.
The Defiance Plateau was a highland and being eroded during most of the Paleozoic. Then windblown sand of the DeChelly Sandstone and the silty redbeds of the Supai Formation covered the core of Precambrian granite and quartzite during the Permian Period. [Note: "Supai" is Arizona terminology. In Colorado or Utah one would use "Cutler." In New Mexico "Abo Formation" would be the preferred name. Baars writes that the Supai here is the same as the Organ Rock Shale, found in Monument Valley.]
Even after being covered with DeChelly Sandstone, the uplift was higher than its surroundings during the early Triassic, thus, the Moencopi Formation, laid down on tidal flats and floodplains, surrounds the Uplift rather than covering it. Later in the Triassic the Chinle Formation did cover the area. Deposition continued through the Mesozoic until the Laramide Orogeny reactivated the faults and lifted the central blocks again, allowing the area to be eroded into its present form.
The southern portion of the monocline is the most dramatic as the eastern limb is sharply flexed, in some places more than 90 degrees. The abrupt flexure is best seen at Black Canyon and Hunters Point. As the western limb seldom dips at more than three degrees, this feature is considered a monocline. The Defiance Uplift includes the Chuska Mountains; the monocline lies more or less in the center of the uplift.
Navajo 12 follows a route along the eastern side through the hogbacks eroded into primarily the Chinle Formation, while Jurassic rocks are visible to the east. As you will see, the monocline does not follow a straight path, but is offset in several places. Notably, near Window Rock the monocline swings northeastward, and the Jurassic Entrada and Cow Springs/Zuni Sandstones are exposed in a hogback capped by Cretaceous Gallup Sandstone.
On this drive watch for livestock on the road, especially in the northern portion as you approach St. Michaels.
At the end of the road log are directions for the benefit of those traveling from Window Rock to Lupton.
Road Log
Take the Lupton/St. Michaels exit off I-40 onto Navajo 12. Set your trip meter to zero as you pass Shirley's Trading Post on the right.
Teapot Rock is on the right at 3.1. For the best view pull off the road just north of the guard rails and look southeast through a gap in the nearest ridge. The Washington expedition left Santa Fe in 1849 to sign another peace treaty with the Navajos. Lt. James H. Simpson, a Topographical Engineer, attached himself to the party. He later filed a report describing geology, flora and fauna, the ruins in Canyon de Chelly and Chaco Canyon, petrified wood in the Bisti region, and the inscriptions at El Morro. Washington’s peace-making expedition was a disaster -- it resulted in the death of the Navajo leader Narbona -- but Simpson's report stood as nearly the only printed information about the region until about 1900.
As the expedition came south along the present route of Navajo 12, Simpson noted a rock column that he said resembled a tankard. Now it is called "the teapot." Erosion may have removed a "top knot" that Simpson showed in his sketch. The Teapot is a column of the Recapture Member. The Recapture is a member of either the Morrison Formation or the Bluff, depending on which school of thought you subscribe to. It rests on a base of Upper Entrada Sandstone. Both are late Jurassic in age.
5.2 A sign welcomes you to the Community of Oak Springs. This settlement is spread out, so you won't see many buildings for a couple of miles.
7.3 Black Canyon: Black Creek has cut through the Defiance Plateau along a fault. The flexure of strata at the mouth of the canyon is not easily seen while traveling north.
15.5 Hunters Point: This is one of the most impressive exposures of a monocline in the Four Corners. I won’t try to describe it; you have to see it. The best vantage point to view the upturned strata is at the base of the grade on the south as you approach this feature. There are a couple of places where you can pull out on the east side of the road to take a picture. A tongue of Abo [Organ Rock Shale or Supai] intrudes into the DeChelly Sandstone and has apparently eroded faster than the DeChelly, creating the prominent notch on the eastern side of the fold.
You may wonder why the folded rock didn’t simply shatter rather than bending. The reason is that when it was deformed it was overlain by hundreds of feet of other stone, which have since been eroded away.
A couple of miles north of Hunters Point the hogback swings east abruptly then back toward the north. You can see knobs or "haystacks" eroded into the Zuni/Cow Springs Sandstone as you approach Window Rock. The natural arch, for which the community is named, is eroded into another knobby exposure of the Zuni/Cow Springs on the north side of the town.
St. Michaels: In 1896-7, when the Navajo Reservation boundary was several miles north of the present location of St. Michaels, The Rev. Mother Katherine Drexel purchased land here to build a mission. She interested the Franciscan Order in the project, and in 1902 a boarding school was opened for Navajo youngsters. In 1910 one of the priests attached to the mission at St. Michaels, Father Berard Haile, published "An Ethnographical Dictionary of the Navajo Language" creating the first written alphabet for the language. The dictionary is still in print. The alphabet that Father Haile invented is rather disconcerting, with lots of double vowels and accent marks. A Navajo woman with a Ph.D. in Chemistry once confessed to me that although Navajo was her first language, she couldn't read it.
On October 1, 2000 the Reverend Mother Katherine Drexel became the second American-born Catholic saint. Although from a rich family, she took vows of poverty at the age of 30 to become a nun. Her $20 million inheritance allowed her to form the Order of the Sisters of the Blessed Sacrament to minister to poor Black and Indian people. She started 48 missions and 65 schools in the South and Southwest, including Xavier University in New Orleans, the first university for African-Americans. Two miracles involving the gift of hearing to children who were born deaf are ascribed to her. She died in 1955 in Philadelphia.
Junction with State 264 and Navajo 3: Turn west for Ganado (Road Log 23), Keams Canyon or Chinle. Turn east to Window Rock.
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Traveling south
You will need these directions to avoid missing the views. Read the descriptions from the text above.
Milepost 16. The view of Hunters Point is on the west just beyond this milepost. There are no good pullouts on the west side of the road, so you may want to watch for one on the other side.
Milepost 11. Looking toward the southwest you can see the folded strata at the entrance to Black Canyon from a little before this milepost and as you travel through the village of Oak Springs.
Milepost 4. As you come to the bottom of the grade past this milepost, stop at the second pullout on the west side of the highway for a view of Teapot Rock.
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Major References
Baars, Donald. Navajo Country; a geology and natural history of the Four Corners Region. University of New Mexico Press, 1995.
Geological Society of America. Rocky Mountain Section. Field Trip Guidebook, 1984.
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