ash+dust are produced from gas-laden viscous magma during an eruption
glassy shards form a rock called welded tuff
particles larger than 64 ml are called blocks
when magma generates vesicular ejecta..its called pumice
surface opening=vent
crater=located at the summit
fumaroles=smoke
shield volcanos are produced by accumulation of fluid basaltic lavas..most form islands or seamounts
cinder cones are built from ejected lava fragments that take on cinders as they begin to harden
cinder cones are the most abundant of the 3 major volcanos
cinders have large deep craters
Mount Etna has cinder cones
most dangerous volcanos are composite cones or stratovolcanos
composite cone=large symetrical structure of lava and pyroclastic deposits
more than 50 volcanos erupted in the U.S. in the past 50 years
glassy shards form a rock called welded tuff
particles larger than 64 ml are called blocks
when magma generates vesicular ejecta..its called pumice
surface opening=vent
crater=located at the summit
fumaroles=smoke
shield volcanos are produced by accumulation of fluid basaltic lavas..most form islands or seamounts
cinder cones are built from ejected lava fragments that take on cinders as they begin to harden
cinder cones are the most abundant of the 3 major volcanos
cinders have large deep craters
Mount Etna has cinder cones
most dangerous volcanos are composite cones or stratovolcanos
composite cone=large symetrical structure of lava and pyroclastic deposits
more than 50 volcanos erupted in the U.S. in the past 50 years