| A | B |
|---|
| viscosity | substance's resistance to flow |
| vent | an opening in the surface of Earth through which molten rock and gases released |
| pyroclastic materials | particles produce in volcanic eruptions |
| volcano | a mountain formed of lava and/or pyroclastic material |
| crater | steep-walled depression at the summit of the volcano |
| shield volcano | broad ,gently sloping volcsno built from fluid basaltic lavas |
| cinder cone | small volcano, built primarilyof pyroclastic materials ejected from a single vent |
| composite cone | a volcano compose of both lava flows and pyroclasric materials |
| caldera | large depression typically caused by collapse or ejection of the summit area of a volcano |
