Puʻu ʻŌʻō, a cinder-and-spatter cone on Kīlauea, Hawaiʻi |
* spatter cones, is formed of molten lava ejected from a vent somewhat like taffy. Expanding gases in the lava fountains tear the liquid rock into irregular gobs that fall back to earth, forming a heap around the vent. The still partly liquid rock splashes down and over the sides of the developing mound is called spatter. Because spatter is not fully solid when it lands, the individual deposits are very irregular in shape and weld together as they cool, and in this way particularly differ from cinder and ash. Spatter cones are typical of volcanoes with highly fluid magma, such as those found in the Hawaiian Islands. The spatter that builds up the cone can either be agglutinated or welded, the former meaning that the individual spatters pose one above each other with a lesser degree of welding occurring, while welded spatter is almost fluid when it lands and therefore welds easily.
Osorno volcano in Chile is an example of a well developed stratocone. |
* tuff cones, and
Example of tuff cone is a diamond head |
Cinder cones rarely rise more than 300 to 750 m or so above their surroundings, and, being unconsolidated, tend to erode rapidly unless further eruptions occur. Cinder cones are numerous in western North America as well as throughout other volcanic terrains of the world. Parícutin, the Mexican cinder cone which was born in a cornfield on February 20, 1943, and Sunset Crater in Northern Arizona in the US Southwest are classic examples of cinder cones, as are the ancient volcanoes in New Mexico's Petroglyph National Monument.
Apagado (Spanish for Extinct, also known as Hualiaque) is a pyroclastic cone with scattered vegetation cover. |