Wheeler Peak
       7 ½’ quadrangle: Wheeler Peak, NM
       Taos County
       Carson National Forest
      Sangre de Cristo Range, Rocky Mountains

Metamorphic (metamorphosed volcanic)
13,161 ft (4,011 m)

Wheeler Peak from the west. (1991)

Bedrock: Unnamed gneiss

Early Proterozoic (older than 1.75 b.y.)

Well foliated fine- to medium-grained biotite gneiss, biotite-hornblende gneiss, hornblende gneiss and amphibolite, interlayered on scales from a few centimeters to several meters. Minerals in these gneisses are quartz, plagioclase, blue-green hornblende, brown biotite, epidote and magnetite. Locally thin lenses of ferruginous quartzite, magnetite ironstone and quartz-epidote-calcite marble are included in the gneiss. The rocks have been severely deformed and contain rootless isoclinal fold noses and other indicators of extremely ductile deformation. The gneiss is intruded by the Red River tonalite, also Early Proterozoic and dated at 1.75 b.y. Walter and Frazier Peaks to the north are made up of the layered gneiss; the younger tonalite lies between them and Wheeler Peak. The gneisses are also locally intruded by diabase dikes. The range was uplifted during the Cretaceous Laramide Orogeny.

Prospectors actively sought copper, gold and silver in the Sangre de Cristo Range, and from 1890 to 1910 copper was mined from the Bull of the Woods mine near Wheeler Peak. The copper occurs as malachite in a northeast-trending shear zone in Precambrian phyllite.

Surficial Geology: The approach via Williams Lake Trail crosses Pleistocene glacial till and a Holocene rock glacier, a lobate deposit of angular rock fragments.

Soil Series: Penitente cobbly loam: Dark brown cobbly loam developed from bedrock residuum in widely scattered depressions between rock outcrops.

Selected References:

• Brown, S. Don, 1982, Mineral Investigation of the Wheeler Peak Wilderness, Taos County, New Mexico : U.S. Bureau of Mines.
• Hacker, Leroy W. and J.O. Carlton, 1982, Soil Survey of Taos County and Parts of Rio Arriba and Mora Counties, New Mexico : U.S. Soil Conservation Service.
• Lipman, P.W. and J.C. Reed, Jr., 1989, Geologic map of the Latir Volcanic Field and adjacent areas, northern New Mexico: U.S. Geological Survey Miscellaneous Field Investigation Series Map I-1907.

Other suggested sources of information:

• Glossary: http://www2.nature.nps.gov/geology/usgsnps/misc/glossaryAtoC.html
• Time scale: http://www.ucmp.berkeley.edu/help/timeform.html
• New Mexico Bureau of Geology and Mineral Resources: http://geoinfo.nmt.edu/
• Wheeler Peak Wilderness: http://www.fs.fed.us/r3/carson/recreation/wilderness/wheeler_peak_info.shtml