Huachuca Mts, Cochise Co., Arizona, USA

‡Ref.: Alexis, C.O. (1949), The geology of the northern part of the Huachuca Mountains, Arizona, University of Arizona, PhD. Thesis.

Weber, R.H. (1950), The geology of the east-central portion of the Huachuca Mountains, Arizona, University of Arizona, PhD. Thesis.

Wilson, E.D., et al (1951), Arizona zinc and lead deposits, part II, Arizona Bureau of Mines Bull. 158: 36-37.

Galbaith, F.W. & D.J. Brennan (1959), Minerals of Arizona: 73.

Hayes, P.T., and Raup, R.B. (1968) Geologic map of the Huachuca and Mustang Mountains, southeastern Arizona: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-509, 1 sheet, scale 1:48,000.

Hayes, P.T. (1970) Mesozoic stratigraphy of the Mule and Huachuca Mountains, Arizona: U.S. Geological Survey Professional Paper 658-A, 28 p.

Crespi, J.M., Currier, D.A., DiTullio, L.D., Kauffman, A.B., and Krantz, R.W. (1982) Superposed faulting in the Huachuca Mountains, southeastern Arizona [abs.]: Geological Society of America Abstracts with Programs: 14(4): 157.

Wohl, E.E., and Pearthree, P.A. (1990) Controls on the origin and recurrence of debris flows in the Huachuca Mountains, southeastern Arizona: Arizona Geological Survey Open-File Report 90-06, 48 p.

Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd. ed.: 142, 234, 343, 374, 396.

Davis, G.H., Crosswhite, J.A., Libarkin, J.C., Ojha, T.P., Riley, B.C., Tindall, S.E., and Woodburne, K.L. (1996) Laramide tear faulting and layer-parallel shearing as accommodations to thrust surge in the Huachuca Mountains, southeastern Arizona [abs.]: Geological Society of America Abstracts with Programs: 28(5): 60.

Huckleberry, Gary (1996) Geomorphology and surficial geology of Garden Canyon, Huachuca Mountains, Arizona: Arizona Geological Survey Open-File Report 96-05, 18 p., 1 sheet, scale 1:12,000.

Yale Peabody GNIS database.

The Huachuca Mountains are in southwestern Cochise County, on the west side of the San Pedro Valley. They form a range approximately 22 miles long by a maximum of 8 miles wide which trends northwestward from the international boundary. The maximum altitude, 9,446 feet, is on Miller Peak, 4,500 feet above the eastern base of the range. The slopes are prevailingly steep and deeply dissected by canyons.

According to Alexis and Weber: Bolsa Quartzite rests upon Precambrian granite and is overlain by limetones and shales of Cambrian, Devonian, Mississippian, Pennsylvanian and Permian ages. Above the permian is a thick succession of conglomerate, sandstone, quartzite, shale, and interbedded volcanic flows, of Lower Cretaceous age. These beds are unconformably overlain by Tertiary (?) volcanic rocks in the northwestern part of the range.

Intruding the Cretaceous and older rocks is a northwestward-trending stock of quartz monzonite which crops out over an area 7 miles long by 2½ miles wide in the southern part of the range, between Montezuma Canyon and Carr Peak. Associated with it are dikes of andesite and quartz-latite porphyry.

The Huachuca Mountains area was successively deformed by folding, broken by thrust and reverse faulting, and subjected to normal faulting.

Folding was apparently initiated previous to thrust faulting, but continued with the development of successively younger thrusts northeastward from the anticlinal axis. Both fold axes and thrust faults strike persistently northwestward, generally paralleling the trend of the range. The thrusts dip prevailingly northeastward at low to high angles.

The development of minor anticlinal and synclinal folds apparently accompanied thrust faulting, in several places resulting in folding of the earlier thrust sheets. Overturned folds and drag folds were also companion features.

The observed major structural deformation apparently began in post-early Cretaceous time, and may have continued into the Tertiary.

The quartz monzonite is largely younger than the major deformation of the range.