| A | B |
|---|
| volcano | an opening in Earth that erupts gases, ash, and lava |
| vent | a opening in the Earth's surface where magma flows out of |
| crater | steep-walled depression around a volcano's vent |
| hot spot | unusually hot area located at the boundary between the Earth's mantle and core |
| shield volcano | broad, gently sloping volcano formed by quiet eruptions of basaltic lava |
| tephra | bits of rock or solidifed lava that drop from the air after an explosive volcanic eruption |
| cinder cone volcano | steep-sided loosely packed volcano formed when tephra falls to the ground |
| composite volcano | volcano built by alternating explosive and quiet eruptions that produce layers of tephra and lava |
| batholith | largest intrusive rock body that forms when magma being forced upward toward Earth's crust cools slowly and solidifies underground |
| dike | igneous rock feature formed when magma is squeezed into a vertical crack that cuts across rock layers and hardens underground |
| sill | igneous rock feature formed when magma is squeezed into a horizontal crack between layers of rock and hardens underground |
| volcanic neck | solid igneous core of a volcano left behind after the softer cone has been eroded |
| caldera | large, circular-shaped opening formed when the top of a volcano collapses |
