|Information Entries for Culebra Peak|
Geology (Sangre de Cristo)
Title: Stratigraphy and Paleogeography of the Northern Sangre de Cristo 14ers
Entered by: shredthegnar10
Added: 05/10/2010, Last Updated: 05/10/2010
Sources: Bolyard, D.W., 1959, Pennsylvanian and Permian stratigraphy of the Sangre de Cristo Mountains between La Veta Pass and Westcliffe, Colorado: American Association of Petroleum Geologists Bulletin, v. 43, p. 1896-1939 Brill, K.G., 1952, Stratigraphy in the Permo-Pennsylvanian zeugogeosyncline of Colorado and northern New Mexico: Geological Society of America Bulletin, v. 63, p. 809-890 Hoy, R.G. and Ridgway, K.D., 2002, Syndepositional thrust-related deformation and sedimentation in an Ancestral Rocky Mountains basin, Central Colorado Trough, Colorado, USA: Geological Society of America Bulletin, v. 114, p.804-828 Lindsey, D.A., Clark, R.F., and Soulliere, S.J., 1986, Minturn and Sangre de Cristo formations of southern Colorado; a prograding fan delta and alluvial fan sequence shed from the Ancestral Rocky Mountains, American Association of Petroleum Geologists Memoir 41, p. 541-561
Crestone Peak, Crestone Needle, Kit Carson Peak, Challenger Peak, and Humboldt Peak all include rocks of the Pennsylvanian (323-299 million years ago) Minturn Formation and the Pennsylvanian-Permian (306-251 million years ago) Sangre de Cristo Formation.
The Sangre de Cristo Formation gradationally overlies the Minturn Formation (meaning that there is no missing time between them), and is defined by the redbeds near the basal part of the Sangre de Cristo Formation. The Minturn Formation consists largely of marine sediments (limestones, siltstones, shales), whereas the Sangre de Cristo Formation consists of primarily nonmarine sediments (arkosic conglomerates, sandstones, siltstones). The shift in the depositional environment resulting in these differences is interpreted as the result of a large-scale sea level regression that occurred during the Middle Pennsylvanian.
The Sangre de Cristo Formation consists of two members (members are kind of like subdivisions of a geologic formation): the Crestone Conglomerate and the Lower Member. The Crestone Conglomerate is defined by the presence of cobble(64-256mm diameter) and boulder (>256mm diameter) sized clasts.
Both the Sangre de Cristo Formation and the Minturn Formation formations were deposited in a sedimentary basin known as the Central Colorado Trough, which was created as a result of the uplift of the Ancestral Rocky Mountains, an indirect result of continental collisions involved in the formation of the supercontinent Pangea. Drainage systems developed to transport eroded material off of these mountains into the basin, and that material is what makes up these formations.
In the limestones of the Minturn Formation, scientists have identified numerous fossils, including fusulinids, brachiopods, crinoids, and bryozoans.
FUN FACT: The sediments of the Sangre de Cristo Formation were deposited during the same time period as the rocks of the Maroon Formation, which make up the Maroon Bells and Pyramid Peak.
Name History (Culebra Peak)
Title: Naming of Culbera Peak
Entered by: 14erFred
Added: 05/14/2010, Last Updated: 05/14/2010
Sources: Hart, J.L.J. (1977). Fourteen thousand feet: A history of the naming and early ascents of the high Colorado peaks (Second Edition). Denver, CO: The Colorado Mountain Club.
The exact origin of Culebra's name is unknown. Culebra is Spanish for "snake" or "harmlesse snake". One theory about the peak's name is that nearby Culebra Creek was named first, for the presence of snakes or for the curviness of the creek. Another theory is that "harmless snake" came from the peak's gentle nature and long curving snakelike northwest ridge. Whichever the case, the peak was named in the early 1800s. Culebra appears on Pike's map, undated and published in 1810, as Rio de la Culebra and appears on Humboldt's map of New Spain in 1811. In his 1847 book, Adventures in Mexico and the Rocky Mountains (London: John Murray, Albemarle Street, 1847), George Ruxton mentions Culebra, Trinchera, and Sangre de Cristo (as streams), while not naming any mountains. Culebra Peak is also shown on Lt. Edward G. Beckwith's map of 1853.