Pisgah Crater

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Pisgah Crater
Pisgah Crater is located in California
Pisgah Crater
Pisgah Crater
Elevation 2,545 ft (776 m) NAVD 88[1]
Prominence 353 ft (108 m)[1]
Location
Coordinates 34°44′47″N 116°22′30″W / 34.7463888°N 116.375°W / 34.7463888; -116.375Coordinates: 34°44′47″N 116°22′30″W / 34.7463888°N 116.375°W / 34.7463888; -116.375
Geology
Type Cinder Cone

Pisgah Crater, or Pisgah Volcano, is a young volcanic cinder cone rising above a lava plain in the Mojave Desert, between Barstow and Needles, California in San Bernardino County, California. The volcanic peak is around 2.5 miles (4.0 km) south of historic U.S. Route 66-National Old Trails Highway and of Interstate 40, and west of the town of Ludlow.[2] The volcano had a historic elevation of 2,638 feet (804 m), but has been reduced to 2,545 feet (776 m) due to mining.[3]

History[edit]

The volcano was the site of the Mount Pisgah Volcanic Cinders Mine, a cinder quarry that produced pumice for commercial use, the primary end product being railroad ballast. The mine is currently owned by Can-Cal Resources Limited, a Canadian company specializing in exploration of precious minerals in California.[4][5] Mining has had a severe environmental impact; the top of the mountain has been removed and the sides of this historically symmertrical mountain have been scoured into an irregular shape. The mountain is still occasionally quarried for various cinder products, and sand from the mountain was used to depict the black sands of Iwo Jima in the film Letters from Iwo Jima.[6]

Geology[edit]

Pisgah Volcano is the youngest vent, of four cinder cones, in the Lavic Lake volcanic field. There may have been activity at this site as recent as 2,000 years ago, though more likely 20,000 to 50,000 years ago. It is too young for the commonly used potassium-argon dating technique usable on specimens over 100,000 years old; as the volcano is basaltic, finding a reliable source of potassium for dating purposes would be difficult anyways. No charred organic material for radiocarbon dating has been found.

Lava at nearby and similarly active Amboy Crater is interbedded with Bristol Playa sediments at a depth of about 9 meters (30 feet) which are approximately 100,000 years old. Recent argon-argon dating reveals an age of approximately 18,000 years ± 5,000 years (~90% certainty) for the most recent flow.[2][7]

Lava flows extend 18 km (11 mi) to the west and 8 km (5.0 mi) to southeast of the cone, containing basalt primarily of the pahoehoe texture, with some a'a. The flows contain numerous lava tubes and caves. The cindercone volcano itself shows signs of oxidization prominent in the reddish/orange/brown appearance of much of the upper portions.

The volcano is a very popular field site for geology instruction. On a weekend, it is not uncommon to find university classes and professional seminar groups around the mountain.

Geography[edit]

Currently, the crater stands 98 meters (321 feet) above the surrounding High Desert terrain, and has a base diameter of 488 meters (1,600 feet).[8] It has lost much of its original cinder cone shape to ongoing aggregate mining operations, in addition to minor natural erosion.[2]

Located in the Basin and Range Province, the Mojave Valley and then the Cady Mountains lie to the north of the peak, while the Rodman Mountains lie to the west. The Lava Bed Mountains lie to the south, and the Bullion Mountains lie to the southeast.

Recreation[edit]

The crater and much of the surrounding lava field are on private property. Despite this, the lava tubes in the area are a somewhat popular and easily accessible destination for caving. Historic Lavic Siding is to the east, with the Mojave National Preserve beyond.

See also[edit]

References[edit]

  1. ^ a b "Pisgah Crater, California". Peakbagger.com. Retrieved 2014-09-26. 
  2. ^ a b c "Lavic Lake". Global Volcanism Program, Smithsonian Institution. http://www.volcano.si.edu/world/volcano.cfm?vnum=1203-19-. Retrieved 2010-07-11.
  3. ^ USGS Sunshine Peak 7.5 topographic map, 1955
  4. ^ MinDat.org
  5. ^ Pisgah 43-101 - Can-Cal Resources Ltd
  6. ^ Letters from Iwo Jima - Filming Locations
  7. ^ Sylvester et al., 2002, Bulletin of the Seismological Society of America, v. 92, p. 1333-1340
  8. ^ http://www.volcano.si.edu/world/volcano.cfm?vnum=1203-19-&volpage=photos . accessed 7/11/2010

External links[edit]