sandstone - a sedimentary rock formed of cemented grains with diameters less than .04 inches.
sedimentary - refers to various aspects of sediments, which are layered deposits of rock and mineral particles.
scoria - a rough-surfaced pyroclastic fragment, baseball to nut size, formed directly from magma and explosively ejected to the surface. It is gaseous and therefore has many bubbles (vesicles) form within the viscous material; synonymus with cinder.
seismograph - a machine that records the intensity of earthquakes.
spatter cone - a small cone made of hot, gas-rich bombs of fluid basalt lava that fall and stick together around a vent.
strata - layers of rock are said to be stratified and are referred to in the plural as stra; an individual layer is a stratum.
Strombolian eruption - an eruption that produces high-arcing incandescent "rooster tails", reminiscent of colorful, fireworks fountains. The ejecta are mainly basaltic cinders and bombs that construct cinder cones. (Named after the Stromboli volcano on the island of Stromboli, off the north coast of Sicily, which erupts in this way.)
Bibliography
Out of the Crater: Chronicles of a Volcanologist, Richard V. Fisher, Princeton University Press, 1999
No comments:
Post a Comment