Needle Rock Natural Area

Needle Rock

Needle Rock in 2016.
Highest point
Elevation 7,797 ft (2,377 m)[1][2]
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[2]
Geography
Needle Rock

Colorado

Location Delta County, Colorado, U.S.[2]
Parent range West Elk Mountains
Topo map USGS 7.5' topographic map
Crawford, Colorado[2]
Geology
Age of rock c.a. 28 Ma
Mountain type Composite volcano
Climbing
Easiest route rock

Needle Rock is an intrusive of rhyodacite volcanic plug[3] located in the Needle Rock Natural Area, 3.5 miles (5.6 km) east-northeast (bearing 68°) of the Town of Crawford in Delta County, Colorado, United States. It stands 800 feet (240 m) tall above the floor of the Smith Fork of the Gunnison River valley. It originated as the throat of a large volcano about 28 million years ago in the Miocene geological epoch, when molten rock intruded between existing sedimentary rocks.[4] The plug may represent the eroded conduit of a laccolith.[3]

See also

References

  1. The elevation of Needle Rock includes an adjustment of +1.473 m (+4.83 ft) from NGVD 29 to NAVD 88.
  2. 1 2 3 4 "Needle Rock". Geographic Names Information System. United States Geological Survey. Retrieved November 6, 2014.
  3. 1 2 "MINERAL RESOURCES OF THE WEST ELK WILDERNESS and vicinity, Delta and Gunnison Counties, Colorado: Open-file report 77-751" (PDF). DEPARTMENT OF THE INTERIOR: UNITED STATES GEOLOGICAL SURVEY. 1977. pp. 16, 85, 98.
  4. "America's Volcanic Past: Colorado". Vancouver, Washington: USGS: Cascades Volcano Observatory (CVO). |chapter= ignored (help)

External links


This article is issued from Wikipedia - version of the Monday, February 29, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.