Cinder cone

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Schematic representation of the internal structure of a typical cinder cone.
Cinders from a Pleistocene cinder cone, San Bernardino Valley, southeastern Arizona.
Holocene cinder cone near Veyo, Utah.

A cinder cone or scoria cone is a steep conical hill of tephra (volcanic debris) that accumulates around and downwind from a volcanic vent.[1]

Mechanics of eruption[edit]

The rock fragments, often called cinders or scoria, are glassy and contain numerous gas bubbles "frozen" into place as magma exploded into the air and then cooled quickly.[1] Cinder cones range in size from tens to hundreds of meters tall.[1] Cinder cones are made of pyroclastic material. Many cinder cones have a bowl-shaped crater at the summit. During the waning stage of a cinder-cone eruption, the magma has lost most of its gas content. This gas-depleted magma does not fountain but oozes quietly into the crater or beneath the base of the cone as lava.[2] Lava rarely issues from the top (except as a fountain) because the loose, uncemented cinders are too weak to support the pressure exerted by molten rock as it rises toward the surface through the central vent.[1] Because it contains so few gas bubbles, the molten lava is denser than the bubble-rich cinders.[2] Thus, it often burrows out along the bottom of the cinder cone, lifting the less-dense cinders like a cork on water, and advances outward, creating a lava flow around the cone's base.[2] When the eruption ends, a symmetrical cone of cinders sits at the center of a surrounding pad of lava.[2] If the crater is fully breached, the remaining walls form an amphitheatre or horseshoe shape around the vent.

Occurrence[edit]

Cinder cones are commonly found on the flanks of shield volcanoes, stratovolcanoes, and calderas.[1] For example, geologists have identified nearly 100 cinder cones on the flanks of Mauna Kea, a shield volcano located on the island of Hawaii.[1] These cones are also referred to as 'scoria cones' and 'cinder and spatter cones.'[1]

The most famous cinder cone, Paricutin, grew out of a corn field in Mexico in 1943 from a new vent.[1] Eruptions continued for 9 years, built the cone to a height of 424 meters, and produced lava flows that covered 25 km².[1]

The Earth's most historically active cinder cone is Cerro Negro in Nicaragua.[1] It is part of a group of four young cinder cones NW of Las Pilas volcano. Since its initial eruption in 1850, it has erupted more than 20 times, most recently in 1995 and 1999.[1]

Based on satellite images it was suggested that cinder cones might occur on other terrestrial bodies in the Solar system too.[3] They were reported on the flanks of Pavonis Mons in Tharsis,[4][5] in the region of Hydraotes Chaos[6] or in the volcanic field Ulysses Colles.[7] It is also suggested that domical structures in Marius Hills might represent lunar cinder cones.[8]

See also[edit]

References[edit]

  1. ^ a b c d e f g h i j k  This article incorporates public domain material from the United States Geological Survey document: "Photo glossary of volcano terms: Cinder cone". 
  2. ^ a b c d  This article incorporates public domain material from the United States Geological Survey document: Susan S. Priest, Wendell A. Duffield, Nancy R. Riggs, Brian Poturalski, and Karen Malis-Clark (2002). "Red Mountain Volcano—A Spectacular and Unusual Cinder Cone in Northern Arizona". USGS Fact Sheet 024-02. Retrieved 2012-05-18. 
  3. ^ Wood, C. A., 1979b. Cinder cones on Earth, Moon and Mars. Lunar Planet. Sci. X, 1370–1372.
  4. ^ Bleacher, J.E., R. Greeley, D.A. Williams, S.R. Cave, and G. Neukum (2007), Trends in effusive style at the Tharsis Montes, Mars, and implications for the development of the Tharsis province, J. Geophys. Res., 112, E09005, doi:10.1029/2006JE002873.
  5. ^ Keszthelyi, L., W. Jaeger, A. McEwen, L. Tornabene, R. A. Beyer, C. Dundas and M. Milazzo (2008), High Resolution Imaging Science Experiment (HiRISE) images of volcanic terrains from the first 6 months of the Mars Reconnaissance Orbiter primary science phase, J. Geophys. Res. 113, E04005, doi:10.1029/ 2007JE002968.
  6. ^ MERESSE, S.; COSTARD, F.; MANGOLD, N.. Formation and evolution of the chaotic terrains by subsidence and magmatism: Hydraotes Chaos, Mars [online]. Icarus 194, 2008. Doi: 10.1016/j.icarus.2007.10.023.
  7. ^ Brož, P., and E. Hauber (2012), An unique volcanic field in Tharsis, Mars: Pyroclastic cones as evidence for explosive eruptions, Icarus, 218, Issue 1, 88–99, doi:10.1016/j.icarus.2011.11.030.
  8. ^ Lawrence, S. J., et al. (2013), LRO observations of morphology and surface roughness of volcanic cones and lobate lava flows in the Marius Hills, J. Geophys. Res. Planets, 118, 615–634, doi:10.1002/jgre.20060.