| A | B |
|---|
| convergent boundary | Fault where tectonic plates move toward each other. |
| volcanism | all processes associated with the discharge of magma, hot water, and steam |
| hot spot | an unusually hot region of Earth's mantle where high-temperature plumes of mantle material rise toward the surface |
| flood basalt | non-viscous lava that erupts from fissures |
| fissure | long cracks in Earth |
| conduit | a tube-like structure that lava flow through to Earth's surface |
| vent | an opening in the crust of a volcano |
| crater | a bowl-shaped depression at the top of a volcano |
| caldera | a very large depression st the top of a volcano |
| shield volcano | a mountain with broad, gently sloping sides and a nearly circular base |
| cinder cone | pile up of debris ejected from a volcano during an eruption |
| composite volcano | mountain that forms from layers of hardened chunks of lava from a violent eruption alternating with layers of lava that moves dowmslope prior to hardening |
| magma | a mixture of molten rock, suspended mineral grains, and dissolved gases beneath Earth's crust |
| viscosity | the internal resistance to flow |
| tephra | rock fragments thrown up into the air during an eruption |
| pyroclastic flow | rapidly moving volcanic material |
| aid | to provide with what is useful or necessary in achieving an end |
| igneous rock | rock formed from the crystallization of magma |
| plutons | intrusive igneous rock bodies |
| stocks | irregularly shaped plutons that are similar to batholiths but smaller |
| sill | a pluton that forms when magma intrudes parallel to layers of rock |
| batholiths | the largest plutons |
| laccolith | a mushroom-shaped plutons with a round top and a flat bottom |
| dike | a pluton that cuts across preexisting rocks |
