Cinder Cone Volcanoes
See how a flat cornfield in Mexico turned into a mountain over almost 360 meters (1000 feet) high and covered 15 square kilometers in only 9 short years.
Cinder cones are the simplest type of volcano. They are built from particles and blobs of congealed lava ejected from a single vent. As the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as cinders around the vent to form a circular or oval cone. Most cinder cones have a bowl-shaped crater at the summit and rarely rise more than a thousand feet or so above their surroundings. Cinder cones are numerous in western North America as well as throughout other volcanic terrains of the world.
2. Cinder cones (notes)
a. Most common, occurs at subduction zones
b. Mostly made of molten andesite rock, some basalt
i. Dissolves lots of gas
c. Very explosive
d. Central vent filled with rock fragments
i. Called cinders
e. Cinders blow out, harden in air, pile around cone like a gravel pile
i. Steep sides, but not very tall (1,000 – 1,200 feet)
f. Weathers & erodes easily, so usually smaller volcano
i. No lava to "glue" cinders together