Volcanic Activity
Practice Test
1.
Which type of information was NOT collected by Wegener to support his continental drift hypothesis?
a.
fossils
b.
rocks
c.
glacial deposits
d.
seafloor magnetic data
2.
How are the convection currents set in motion?
a.
slab push
b.
the heat from radioactive decay
c.
spreading mid-ocean ridges
d.
slab push and ridge pull
3.
Wegener proposed that the continents were __________.
a.
formed at deep ocean trenches
b.
floating on top of oceanic crust
c.
plowing through oceanic crust
d.
formed at mid-ocean ridges
4.
Where is andesitic magma found?
a.
at the margins of continents
b.
in the middle of oceanic crust
c.
inside of continental crust
d.
on islands in the Pacific, such as Hawaii
5.
What is the shallowest part of the continental margin called?
a.
a submarine canyon
b.
the continental shelf
c.
the shelf break
d.
the continental rise
6.
A tabular pluton that cuts across preexisting rock is called a __________.
a.
stock
b.
laccolith
c.
dike
d.
sill
7.
Granite is an example of __________ rock.
a.
an intrusive igneous
b.
an extrusive igneous
c.
a partially melted
d.
a volcanic ash
8.
What is the last mineral to form on the left branch of Bowen's reaction series?
a.
feldspar
b.
pyroxene
c.
quartz
d.
olivine
9.
What is an isochron?
a.
a line on a seafloor map that connects points of equal elevation
b.
a point on a seafloor map that has a magnetic reversal
c.
a part of a mid-ocean ridge
d.
a line on a seafloor map that connects points of equal age
10.
What type of igneous pluton is tabular and parallel to surrounding rock layers?
a.
a sill
b.
a stock
c.
a batholith
d.
a dike
11.
According to the map shown in the figure, which area of Earth contains the highest concentrations of quartz and feldspars?
a.
Hawaii
b.
the Pacific Ocean
c.
North America
d.
the west coast of the U.S.
12.
Where do most volcanoes form?
a.
in the southern hemisphere
b.
along the Mid-Atlantic Ridge
c.
far from plate boundaries
d.
at plate boundaries
13.
What causes the seafloor to spread?
a.
rising molten magma
b.
sinking magma
c.
drifting continental crust
d.
earthquakes
14.
What type of magma has the lowest silica content and is the least explosive?
a.
basaltic magma
b.
andesitic magma
c.
rhyolitic magma
d.
granitic magma
15.
Places where two tectonic plates are moving away from each other are called __________.
a.
divergent boundaries
b.
earthquake boundaries
c.
convergent boundaries
d.
transform boundaries
16.
According to the figure, what types of minerals are ultramafic?
a.
pyroxine and olivine
b.
feldspar and quartz
c.
amphibole and pyronene
d.
feldspar and biotite
17.
What is thought to be the driving mechanism of plate movement?
a.
conduction of heat in the mantle
b.
continental drifting
c.
volcanoes
d.
convection currents in the mantle
18.
What breaks mid-ocean ridges into smaller sections?
a.
shelf breaks
b.
abyssal plains
c.
submarine canyons
d.
fracture zones
19.
Where do tectonic plates interact?
a.
at plate boundaries
b.
in deep-sea trenches
c.
at plate centers
d.
at mid-ocean ridges
20.
How was the volcano cone shown in the figure formed?
a.
material is ejected into the air and falls back to earth
b.
uplifting of mountains before exploding into a volcano
c.
a mixture of lava and volcanic fragments
d.
layer upon layer of basaltic lava accumulating during nonexplosive eruptions
