New Mexico Museum of Natural History and Science

 

Chuska-Ship Rock (Navajo) field


Location: Chuska Volcanic Field, approx. 35° 25' to 37° N and 108° 25' 109° Ship Rock, 36° 41' N, 108° 40' W, County
Type: Group of intrusions and associated extrusive rocks. (Chuska Mountains, northwestern New Mexico)
Age: Middle Oligocene; fission track ages at Ship Rock (on southern dike) 27 ?3 and 32?3 million years; K-Ar, 30.6 million years
Significance:

Composition:

 Basic Geology

The Navajo volcani fields, also known as the Chuska volcanic field, is a diffuse group of intrusions, dikes, and some extrusive rocks of mid-Tertary age scattered between Gallup and Farmington, New Mexico and Window Rock, Arizona, the most famous of which is Ship Rock. Intrusive rocks in the Navajo volcanic field, like most Colorado Plateaus province intrusives, include some unusual petrologies: minette, vogesite, basaltic tuff, and tuff breccia. The Buell Park diatreme, which consists of kimberlite, is also part of the field. Minette consists of alkali feldspar, biotite or phlogopite, and diopside. Diopside (pyroxene), phlogopitic biotite and olivine occur as phenocrysts in many hand samples. 

 

Additional Information:

Petrology/ General Geology:

Appledorn, C.R., and H.W. Wright,Jr., Volcanic structures in the Chuska Mountains, Navajo Reservation, Arizona-New Mexico. Geol. Soc. America Bulletin, 68, 445-467, 1957.

Beaumont, E.C., Preliminary geologic map of the Ship Rock and Hogback quadrangles, San Juan County, New Mexico. U. S. Geol. Survey Coal Investigation Map C-29, scale 1:48,000, 1955.

Ehrenberg, S.N., Petrology of potassic volcanic rocks and ultramafic xenoliths from the Navajo volcanic field, New Mexico and Arizona. Los Angeles, Univ. California. Ph.D. thesis, 259p., 1978.

Gregory, H.E., Geology of the Navajo country. U. S. geol. Survey Professional Paper 93, 161p., 1917.

Naeser, C.W., Geochronology of the Navajo-Hopi diatremes, Four Corners area [Colorado]. Jour. Geophys. Res., 76, 4978-4985, 1971.
Nicholls, J. W., Studies of the volcanic petrology of the Navajo-Hopi area, Arizona. Berkely, Univ. California, Ph.D. thesis, 107p., 1969.
Semken, S.C., The Navajo volcanic field, Volcanology in New Mexico, New Mexico Museum of Natural History and Science Bulletin 18, p. 79-83. Williams, H., Plocene volcanoes of the Navajo-Hopi country. Geol. Soc. America Bulletin, 47, 111-171, 1936.

Volcanology/Dike Mechanics:

Delaney, P. T., and D. Pollard, Deformation of host rocks and flow of magma during growth of minette dikes and breccia-bearing intrusions near Ship Rock, New Mexico. U. S. Geol. Survey Professional Paper 1201, 61p., 1981.