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)
“And in the next instant, immediately behind them, Victor saw his former wife.
At once he lowered his gaze, automatically tapping his cigarette to dislodge the ash that had not yet had time to form. From somewhere low down his heart rose like a fist to deliver an uppercut, drew back, struck again, then went into a fast disorderly throb, contradicting the music and drowning it.”
—Vladimir Nabokov (1899–1977)
“...there was the annual Fourth of July picketing at Independence Hall in Philadelphia. ...I thought it was ridiculous to have to go there in a skirt. But I did it anyway because it was something that might possibly have an effect. I remember walking around in my little white blouse and skirt and tourists standing there eating their ice cream cones and watching us like the zoo had opened.”
—Martha Shelley, U.S. author and social activist. As quoted in Making History, part 3, by Eric Marcus (1992)