Needle Rock Natural Area

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Needle Rock
Needle Rock is located in Colorado
Needle Rock
Needle Rock
Colorado
Elevation 7,797 ft (2,377 m)[1][2]
Location
Location Delta County, Colorado, U.S.[2]
Range West Elk Mountains
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]
Topo map USGS 7.5' topographic map
Crawford, Colorado[2]
Geology
Type Composite volcano
Age of rock c.a. 28 Ma
Climbing
Easiest route rock

Needle Rock is an intrusive of rhyodacite volcanic plug[3] located at the west border of the Gunnison National Forest, in the Needle Rock Natural Area near Crawford in the U.S. state of Colorado. 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[edit]

References[edit]

  1. ^ The elevation of Needle Rock includes an adjustment of +1.473 m (+4.83 ft) from NGVD 29 to NAVD 88.
  2. ^ a b c d "Needle Rock". Geographic Names Information System, U.S. Geological Survey. Retrieved November 6, 2014. 
  3. ^ a b "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. ^ "Needle Rock Natural Area". "America's Volcanic Past: Colorado". Vancouver, Washington: USGS: Cascades Volcano Observatory (CVO). 

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