Needle Rock Natural Area

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Needle Rock[1]
Needle Rock Natural Area.JPG
Needle Rock in 2016.
Highest point
Elevation 7,797 ft (2,377 m)
Coordinates 38°43′28″N 107°33′00″W / 38.7244335°N 107.5500571°W / 38.7244335; -107.5500571Coordinates: 38°43′28″N 107°33′00″W / 38.7244335°N 107.5500571°W / 38.7244335; -107.5500571
Geography
Needle Rock is located in Colorado
Needle Rock
Needle Rock
Location Delta County, Colorado, U.S.
Parent range West Elk Mountains
Topo map USGS 7.5' topographic map
Crawford, Colorado
Geology
Age of rock c.a. 28 Ma
Mountain type Igneous Intrusion
Climbing
Easiest route rock

Needle Rock Natural Area[1] is located at the western edge of the West Elk Mountains of Colorado. The surrounding terrain is characterized by laccolithic mountains flanked by precipitous cliffs, extensive talus aprons, forested mesas, canyons, and spacious, well-watered intermontane basins.[2] Needle Rock is an intrusive plug of monzonite porphyry[3] cropping out 3.5 miles (5.6 km) east-northeast (bearing 68°) of the Town of Crawford in Delta County, Colorado, United States. At an elevation of 7,797 feet (2,377 m),[4] the towering rock spire stands 800 feet (240 m) tall above the floor of the Smith Fork of the Gunnison River valley. The massive rock feature originated in the Oligocene geological epoch when magma intruded between existing sedimentary rocks[5] as the crown of a buried laccolith[3] or possibly the underlying conduit of a laccolith.[2] Subsequent erosion has exposed the prominent rock formation seen in the natural area today.

The Needle Rock Natural Area is managed by the Bureau of Land Management.[6]

See also[edit]

References[edit]

  1. ^ a b "Needle Rock". Geographic Names Information System. United States Geological Survey. 
  2. ^ a b "Mineral Resources of the West Elk Wilderness and Vicinity, Delta and Gunnison Counties, Colorado: Open-file report 77-751, 110 pp" (PDF). Department of the Interior: United States Geological Survey. 1977. 
  3. ^ a b Noe, D. C., and Alexander T. Klink. “OF-15-06 Geologic Map of the Crawford Quadrangle, Delta and Montrose Counties, Colorado.” Geologic, 1:24,000. Open File Report. Golden, CO: Colorado Geological Survey, 2015.
  4. ^ The elevation of Needle Rock includes an adjustment of +1.473 m (+4.83 ft) from NGVD 29 to NAVD 88.
  5. ^ "America's Volcanic Past: Colorado". Vancouver, Washington: USGS: Cascades Volcano Observatory (CVO). 
  6. ^ BLM Needle Rock Natural Area Webpage

External links[edit]

Needle Rock Article - summitpost.org