| A | B |
|---|
| volcanism | any activity that includes the activity of magma towards on onto the earths surface |
| magma | solid rock that melts; liquid rock |
| lava | magm that erupts onto the earth surface |
| volcano | lava and pyroclastic material built up around the earth's surface around a vent |
| mafic lava | dark colored when hardened and is rich in magnesuim and iron. |
| felsic lava | lighter color when hardened |
| pahoehoe | solidified mafic lava with a wrinkled surface |
| aa | jaggid chunks of lava formed by rapid cooling on the sufrface of a lava flow |
| pillow lava | lava that flows out of fissures on the ocean floor and cools rapidly in rounded shapes |
| pyroclastic material | the rock fragments ejected forom a volcano |
| volcanic ash | pyroclastic particles between 0.25 m and 2 mm in diameter |
| volcanic dust | pyroclastic particles less than 0.25 mm in diameter |
| volcanic bombs | large, spindle-shaped clot of lava thrown out of a volcano |
| volcanic blocks | the largest possible pyroclastic material that is formed from solid rock blasted from a volcanic fissure. |
| shield volcanoes | has a cone of hardened lava that forms a broad base and gentle slopes |
| cinder cones | steep-sloped deposit of solid fragments ejected from a volcano |
| composite volcanoes | also called stratocolcano, steep-sloped vocanic deposit with alternationg layers of hardened lava flows and pyroclastic materials |
| stratovolcanoes | also called composite colcano, steep-sloped volcanic deposit with alternating layers of hardened lava flows and pyroclastic material |
| crater | funnel shaped pit at the top of a volcanic cone; bowl shaped depression on the surface of a planetary body |
| caldera | large basin-shaped depression formed when an explosion destroys the upper part of a colcanic cone or when the magma chamber below a volcano is emptied during an eruption |
