Ash and Tuff Cones
See also: Phreatomagmatic eruptionAn ash cone is composed of particles of silt to sand size. Explosive eruptions from a vent where the magma is interacting with groundwater or the sea (as in an eruption off the coast) produce steam and are called phreatic. The interaction between the magma, expanding steam, and volcanic gases results in the ejection of mostly small particles called ash. Fallen ash has the consistency of flour. The unconsolidated ash forms an ash cone which becomes a tuff cone or tuff ring once the ash consolidates (see also tuff). Flat-floored craters that scientists interpret have formed above diatremes as a result of a violent expansion of magmatic gas or steam; deep erosion of a maar presumably would expose a diatreme.
An example of a tuff cone is Diamond Head at Waikīkī in Hawaiʻi.
Read more about this topic: Volcanic Cone
Famous quotes containing the words ash and, ash and/or cones:
“Greasing the bodies of adulterers
Like Hiroshima ash and eating in.
The sin. The sin.”
—Sylvia Plath (1932–1963)
“Of the crow-blue mussel shells, one keeps
adjusting the ash heaps;
opening and shutting itself like
an
injured fan.”
—Marianne Moore (1887–1972)
“Here was a little of everything in a small compass to satisfy the wants and the ambition of the woods,... but there seemed to me, as usual, a preponderance of children’s toys,—dogs to bark, and cats to mew, and trumpets to blow, where natives there hardly are yet. As if a child born into the Maine woods, among the pine cones and cedar berries, could not do without such a sugar-man or skipping-jack as the young Rothschild has.”
—Henry David Thoreau (1817–1862)