LSU GEOL 1001 EXAM 2 COMPREHENSIVE
QUESTIONS AND CORRECT ANSWERS
◉ At which of the sites shown in this figure would melting probably
be caused by introduction of water into hot rocks.
Answer: C
◉ which of the following igneous rocks has a texture consistent with
a magma that cooled and solidified slowly at first, followed by more
rapid cooling?
a. small felsic crystals enclosed in large mafic ones
b. small mafic crystals enclosed in large felsic ones
c. large crystals like those in pegmatite
d. large, early formed crystals surrounded by smaller, late formed
crystals.
Answer: d. large, early formed crystals surrounded by smaller, late
formed crystals
◉ an igneous rock that solidifies below the surface is called
a. magma rock
,b. lava rock
c. extrusive rock
d. intrusive rock.
Answer: d. intrusive rock
◉ Coarsely crystalline igneous textures indicate that:
a. the rock cooled slowly
b. the rock cooled quickly
c. the rock broke apart as it flowed
d. the ash and pumice were hot and became compacted
e. there was a lot of gas in the magma.
Answer: a. the rock cooled slowly
◉ examine this figure and correctly complete this sentence using the
proper phrase:
Changing conditions from points ____ would result in decompression
melting..
Answer: C to B
◉ which of the following is characteristic of continental rifts?
,a. some magmas are felsic and intermediate
b. heat from hot, mafic magma can melt continental crust
c. solid asthenosphere undergoes decompression melting
d. all of the above.
Answer: d. all of the above
◉ an igneous rock that solidifies on earth's surface is called:
a. extrusive rock
b. intrusive rock
c. vesicular rock
d. magma rock.
Answer: a. extrusive rock
◉ which of the following processes could result in a felsic magma?
a. partial melting of an intermediate-composition source
b. partial melting of continental crust
c. formation and settling of mafic crystals in an intermediate magma
d. all of the above.
Answer: d. all of the above
, ◉ continental rifts have a diverse suite of igneous rocks associated
with them because melting occurs
a. only in the crust
b. in the mantle and in the crust
c. only in the mantle.
Answer: b. in the mantle and in the crust
◉ the igneous feature shown in this figure is a
a. volcanic neck
b. dike
c. sill
d. laccolith.
Answer: c. sill
◉ steep and unstable slopes can produce ____, forming ____.
Answer: landslides and mudflows; volcanic breccia
◉ magma erupted on the surface can form a ____ that cools quickly,
resulting in ____.
QUESTIONS AND CORRECT ANSWERS
◉ At which of the sites shown in this figure would melting probably
be caused by introduction of water into hot rocks.
Answer: C
◉ which of the following igneous rocks has a texture consistent with
a magma that cooled and solidified slowly at first, followed by more
rapid cooling?
a. small felsic crystals enclosed in large mafic ones
b. small mafic crystals enclosed in large felsic ones
c. large crystals like those in pegmatite
d. large, early formed crystals surrounded by smaller, late formed
crystals.
Answer: d. large, early formed crystals surrounded by smaller, late
formed crystals
◉ an igneous rock that solidifies below the surface is called
a. magma rock
,b. lava rock
c. extrusive rock
d. intrusive rock.
Answer: d. intrusive rock
◉ Coarsely crystalline igneous textures indicate that:
a. the rock cooled slowly
b. the rock cooled quickly
c. the rock broke apart as it flowed
d. the ash and pumice were hot and became compacted
e. there was a lot of gas in the magma.
Answer: a. the rock cooled slowly
◉ examine this figure and correctly complete this sentence using the
proper phrase:
Changing conditions from points ____ would result in decompression
melting..
Answer: C to B
◉ which of the following is characteristic of continental rifts?
,a. some magmas are felsic and intermediate
b. heat from hot, mafic magma can melt continental crust
c. solid asthenosphere undergoes decompression melting
d. all of the above.
Answer: d. all of the above
◉ an igneous rock that solidifies on earth's surface is called:
a. extrusive rock
b. intrusive rock
c. vesicular rock
d. magma rock.
Answer: a. extrusive rock
◉ which of the following processes could result in a felsic magma?
a. partial melting of an intermediate-composition source
b. partial melting of continental crust
c. formation and settling of mafic crystals in an intermediate magma
d. all of the above.
Answer: d. all of the above
, ◉ continental rifts have a diverse suite of igneous rocks associated
with them because melting occurs
a. only in the crust
b. in the mantle and in the crust
c. only in the mantle.
Answer: b. in the mantle and in the crust
◉ the igneous feature shown in this figure is a
a. volcanic neck
b. dike
c. sill
d. laccolith.
Answer: c. sill
◉ steep and unstable slopes can produce ____, forming ____.
Answer: landslides and mudflows; volcanic breccia
◉ magma erupted on the surface can form a ____ that cools quickly,
resulting in ____.
