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Mammoth Mountain

Lava dome · United States · 3369m

Mammoth Mountain, a Pleistocene trachydacitic lava-dome complex constructed on the SW topographic rim of the Long Valley caldera between about 200,000 and 50,000 years ago, forms the broad peak on the horizon. The Red Cones (center and lower left) are part of series of about three dozen mafic cones surrounding Mammoth Mountain. The oxidized reddish scoria of the cone, which was formed during the early Holocene, is mantled at its base by light-colored pumice erupted from the Inyo Craters about 650 years ago.
Mammoth Mountain, a Pleistocene trachydacitic lava-dome complex constructed on the SW topographic rim of the Long Valley caldera between about 200,000 and 50,000 years ago, forms the broad peak on the horizon. The Red Cones (center and lower left) are part of series of about three dozen mafic cones surrounding Mammoth Mountain. The oxidized reddish scoria of the cone, which was formed during the early Holocene, is mantled at its base by light-colored pumice erupted from the Inyo Craters about 650 years ago. · Photo: Photo by Lee Siebert, 1998 (Smithsonian Institution) · Wikimedia Commons
Type
Lava dome
Country
United States
Region
North America Volcanic Regions / Basin and Range Volcanic Province
Elevation
3369m
Coordinates
37.631, -119.032
Last eruption
1260
Tectonic setting
Rift zone / Continental crust (> 25 km)
Landform
Minor
Major rock type
Trachyte / Trachydacite
Geological summary

Mammoth Mountain, a trachydacitic lava-dome complex, lies on the SW topographic rim of Long Valley caldera. It is west of the structural rim of the caldera and considered to represent a magmatic system distinct from other nearby volcanic regions (Hildreth, 2004). The latest magmatic eruptions took place about 57,000 years ago. Mammoth Mountain is surrounded by at least 35 mafic vents that are part of the same magmatic system and include Red Cones, two closely spaced basaltic cinder cones SW of Mammoth Mountain and SE of Devils Postpile National Monument. The cones, whose name derives from colorful scoria deposits, are unglaciated and were radiocarbon dated at about 8,500 years ago. Phreatic eruptions, distinct from those at South Inyo Craters, took place about 700 years ago from vents on the north side of Mammoth Mountain. Recent unrest, including seismicity, gas emission, and tree kill, is thought to be related to dike intrusion in 1989.

From Wikipedia

Mammoth Mountain is a lava dome complex partially located in the town of Mammoth Lakes, California, within the Inyo National Forest of Madera and Mono counties. It is home to a large ski area primarily on the Mono County side.

Wikipedia · CC BY-SA · Read full article →

Eruption history

Summary (VEI over time)
Click a bar to see individual eruptions
6540 BCE~6280 BCE · 1 eruptions · max VEI 21000~1260 · 1 eruptions · max VEI ?6540 BCE4720 BCE2640 BCE820 BCE1000

Detailed timeline

  1. 1260 (±40 yrs)VEI ?Geological estimate
    1260 – Ongoing
    North flank of Mammoth Mountain
  2. 6540 BCE (±90 yrs)VEI 2Geological estimate
    BCE 6540 – Ongoing
    SSW of Mammoth Mtn (Red Cones)

External links

⚠ For reference only. Not for emergency response.