GEOLOGY 1301 Final Exam QUESTIONS
AND CORRECT ANSWERS
Asthenosphere - CORRECT ANSWER The upper layer of the earth's mantle and the main
source of magma
Lava - CORRECT ANSWER Erupted magma
Volcanoes - CORRECT ANSWER A mountain or hill with a crater through which lava, rock
fragments, hot vapor, and gas are erupted from the earth's crust.
Fissure eruption - CORRECT ANSWER Highly fluid basalt erupts from fissures
Fissure - CORRECT ANSWER Surface crack in rock
Basaltic lava - CORRECT ANSWER Hot fluid, gentle eruptions
Pohoehoe - CORRECT ANSWER Basaltic pillow lavas
Andesitic lava - CORRECT ANSWER Eruptions along subduction zones
Rhyolitic lava - CORRECT ANSWER Most explosive (Yellowstone)
Vesicles - CORRECT ANSWER Air filled cavities (holes) in rocks formed from lava
Pyroclasts - CORRECT ANSWER Clastic rocks composed primarily of volcanic materials
Volcanic rocks - CORRECT ANSWER Reflect the conditions under which they formed
Volcanic tuff - CORRECT ANSWER Rocks from finely grained pyroclasts
, Volcanic breccia - CORRECT ANSWER Rocks from coarsely grained pyroclasts
Lavas from hottest to least hottest: - CORRECT ANSWER Basaltic, Andesitic, Rhyolitic
Shield volcanoes - CORRECT ANSWER Broad, domed volcano that erupts basaltic lava
Cinder cones - CORRECT ANSWER A cone formed around a volcanic vent by fragments of
lava
Stratovolcanoes - CORRECT ANSWER A volcano built up of alternate layers of lava and ash
Craters - CORRECT ANSWER Rough circular depressions in the ground caused by volcanic
activity, usually accompanied by a vent
Caldera - CORRECT ANSWER Formed when walls of a volcano fall after the emptying of a
magma chamber
Flood basalts - CORRECT ANSWER The result of a large volcanic eruption, covering the
ground with basalt lava
Example of a flood basalt - CORRECT ANSWER Columbia Plateau, Washington
Ash-flow deposit - CORRECT ANSWER Poorly sorted deposits of pyroclastic material
Large Igneous Province - CORRECT ANSWER Large accumulation of igneous rocks arising
when magma flows
Earthquakes - CORRECT ANSWER Occur where stressed rocks suddenly break along a fault
Seismic waves - CORRECT ANSWER Ground vibrations caused by rocks slipping along
opposite sides of a fault
AND CORRECT ANSWERS
Asthenosphere - CORRECT ANSWER The upper layer of the earth's mantle and the main
source of magma
Lava - CORRECT ANSWER Erupted magma
Volcanoes - CORRECT ANSWER A mountain or hill with a crater through which lava, rock
fragments, hot vapor, and gas are erupted from the earth's crust.
Fissure eruption - CORRECT ANSWER Highly fluid basalt erupts from fissures
Fissure - CORRECT ANSWER Surface crack in rock
Basaltic lava - CORRECT ANSWER Hot fluid, gentle eruptions
Pohoehoe - CORRECT ANSWER Basaltic pillow lavas
Andesitic lava - CORRECT ANSWER Eruptions along subduction zones
Rhyolitic lava - CORRECT ANSWER Most explosive (Yellowstone)
Vesicles - CORRECT ANSWER Air filled cavities (holes) in rocks formed from lava
Pyroclasts - CORRECT ANSWER Clastic rocks composed primarily of volcanic materials
Volcanic rocks - CORRECT ANSWER Reflect the conditions under which they formed
Volcanic tuff - CORRECT ANSWER Rocks from finely grained pyroclasts
, Volcanic breccia - CORRECT ANSWER Rocks from coarsely grained pyroclasts
Lavas from hottest to least hottest: - CORRECT ANSWER Basaltic, Andesitic, Rhyolitic
Shield volcanoes - CORRECT ANSWER Broad, domed volcano that erupts basaltic lava
Cinder cones - CORRECT ANSWER A cone formed around a volcanic vent by fragments of
lava
Stratovolcanoes - CORRECT ANSWER A volcano built up of alternate layers of lava and ash
Craters - CORRECT ANSWER Rough circular depressions in the ground caused by volcanic
activity, usually accompanied by a vent
Caldera - CORRECT ANSWER Formed when walls of a volcano fall after the emptying of a
magma chamber
Flood basalts - CORRECT ANSWER The result of a large volcanic eruption, covering the
ground with basalt lava
Example of a flood basalt - CORRECT ANSWER Columbia Plateau, Washington
Ash-flow deposit - CORRECT ANSWER Poorly sorted deposits of pyroclastic material
Large Igneous Province - CORRECT ANSWER Large accumulation of igneous rocks arising
when magma flows
Earthquakes - CORRECT ANSWER Occur where stressed rocks suddenly break along a fault
Seismic waves - CORRECT ANSWER Ground vibrations caused by rocks slipping along
opposite sides of a fault
