[Geology-G100] Chapter 5: Volcanoes

Batholith

Dike

Sill

Volcanic Neck

Columnar Basalts

Crater Lakes

Fissures

1A. What type of volcano is Mount St. Helens? a. Plinian b. Composite c. Cinder cone d. Shield

Describe aa lava

Describe pahoehoe ("pa-hoy-hoy") lava

What are pyroclastics?

3A. Which of the following objects has a size similar to that of lapilli? a. A marble (15 mm) b. Mechanical pencil lead (0.5 mm) c. A soccer ball (220 mm) d. A grain of salt (1 mm) e. A softball (96 mm)

3B. Volcanic ash is best described as which of the following? a. Sand-sized pieces of rock ejected by a volcano b. Microscopic pieces of rock ejected by a volcano c. Football-sized pieces of rock that are ejected into the air by an erupting volcano d. Remnants from organic material burned by the erupting volcano e. The crust on top of a lava flow

3D. Which of the following is the volcanic feature in which magma rises through before it is released at the surface? a. Parasitic cone b. Crater c. Lava tube d. Vent e. Conduit

4A. How did the Hawaiian islands form in the Pacific Ocean?

4B. Which materials in Hawaii's lava help to keep it fluid for longer at the surface (as opposed to cooling and solidifying quickly), thus allowing extensive lava flows to develop? [ ] magnesium [ ] water [ ] iron [ ] silica [ ] sulfur

4D. Which of the following has the single most immediate effect on lava's ability to solidify? a. chemical composition b. gas content c. temperature d. steepness of slope e. water content

5B. The production of magma (magmatism) at divergent boundaries is characterized by which of the following? [ ] Melting caused by decompression [ ] Outpourings of lava/magma originating from the mantle. [ ] Melting caused by subduction [ ] Outpourings of lava/magma originating mostly from the continental crust.

6B. What information do geologists use to classify volcanoes? a. Color and height of peak b. Shape and height of peak c. Shape and type of deposits d. Height of peak and type of deposits e. Color and type of deposits

6C. Cinder cones are made of ________. a. Basalt flows b. Granite flows c. Pyrobasalt deposits d. Pyroclastic deposits e. Andesitic lava

6D. In general, how often do most cinder cones erupt? a. Most cinder cones erupt once. b. Most cinder cones do not erupt. c. Most cinder cones erupt annually. d. Most cinder cones erupt seasonally. e. Most cinder cones erupt several times each decade.

6E. What are shield volcanoes generally made of? a. Pyroclastic deposits b. Pyrobasalt deposits c. Basalt flows d. andesitic lava e. Granite flows

6F. What is the range of shield volcano height? a. 300 to 1,000 meters b. 1,000 to 3,000 meters c. 300 to 10,000 meters d. 3,000 to 10,000 meters

6G. What are composite volcanoes made of? Choose all that apply. [ ] Basalt flows [ ] Granite flows [ ] Pyrobasalt deposits [ ] Andesitic lava [ ] Pyroclastic deposits

6H. Why are shield volcanoes wider than composite volcanoes? a. The lava that flows out of shield volcanoes is less fluid than the lava that flows out of composite volcanoes. b. The pyroclastic material that comes out of shield volcanoes is more fluid than the lava that flows out of composite volcanoes. c. The pyroclastic material that comes out of shield volcanoes is less fluid than the lava that flows out of composite volcanoes. d. The lava that flows out of shield volcanoes is more fluid than the lava that flows out of composite volcanoes.

6I. What type of magma erupts out of dome complexes? a. Mafic magma b. Mafelsic c. Felmafic magma d. Felsic magma

6J. What type of volcanoes have the greatest total height? a. Dome complexes b. Composite volcanoes c. Shield volcanoes d. Cinder cones

6K. What is the range of dome complex height? a. 20 to 500 meters b. 500 to 2,000 meters c. 200 to 500 meters d. 20 to 5,000 meters