What is Scoria?
March 19, 2013 | Geology.com
Scoria is a dark-colored igneous rock with abundant gas vesicles. It is used to make lightweight concrete and as a landscape aggregate. Nature uses it as the construction material for cinder cones.
Calderas on the Chiltepe Peninsula
February 18, 2014 | NASA Earth Observatory
The Chiltepe Peninsula extends into the waters of Lake Managua, Nicaragua. It is part of an ignimbrite shield with two calderas produced from the ejecta of numerous volcanic eruptions.
Concrete Canoe Race
June 26, 2013 | New York Times
At the National Concrete Canoe Competition, civil engineering students race in canoes that they have designed and made - out of concrete.