The Precambrian Earth
Practice Test
1.
What is an erosional contact between sedimentary and nonsedimentary rocks called?
a.
a fault
b.
a disconformity
c.
a nonconformity
d.
a lava flow
2.
How were asteroids and meteorites a heat source for Precambrian Earth?
a.
Their impact on Earth generated energy.
b.
Their radioactive decay of isotopes generated energy.
c.
Their gravitational contraction generated energy.
d.
Their bombardment of Earth caused them to sink to the core.
3.
Which is not a region of the Appalachian Mountain belt?
a.
The Blue Ridge
b.
the Adirondack Mountains
c.
the Valley and Ridge
d.
the Piedmont Province
4.
A gravel-sized particle in a conglomerate is __________ the conglomerate rock.
a.
older than
b.
always ten times older than
c.
the same age as
d.
younger than
5.
__________ are the building blocks of proteins.
a.
Formaldehyde molecules
b.
Cyanide molecules
c.
Amino acids
d.
DNA and RNA
6.
What was the original composition of Earth's atmosphere?
a.
hydrogen and helium
b.
nitrogen and carbon dioxide
c.
ammonia and hydrogen
d.
water vapor and methane
7.
What was the composition of Earth's first crust?
a.
iron and quartz
b.
feldspar, quartz, and mica
c.
feldspar
d.
iron- and magnesium-rich minerals
8.
According to the figure, where is an earthquake's focus most likely to occur?
a.
in the middle of the Pacific Ocean
b.
along the west coast of North America
c.
in northern Eurasia
d.
near the south pole
9.
Places where two tectonic plates are moving away from each other are called __________.
a.
earthquake boundaries
b.
convergent boundaries
c.
transform boundaries
d.
divergent boundaries
10.
What were the type of life-forms that existed before the Proterozoic?
a.
algae
b.
eukaryotes
c.
fungi
d.
prokaryotes
11.
What layer is shown right above the thermocline (around 1000 meters deep) in the graph?
a.
surface layer
b.
top layer
c.
thermal layer
d.
bottom layer
12.
What principle of geology states that sedimentary rocks are deposited horizontally or nearly horizontally?
a.
uniformitarianism
b.
original horizontality
c.
superposition
d.
cross-cutting relationships
13.
What are areas called that contain cores of Archean and Proterozoic rock?
a.
continental crust
b.
Precambrian shields
c.
Canadian shields
d.
Archean shields
14.
What type of volcanic peaks are made by the boundary pictured in the figure?
a.
trenches
b.
hot spots
c.
batholiths
d.
island arc complexes
15.
The oldest rocks on Earth are __________.
a.
1.6 to 1.8 million years old
b.
3.96 to 3.8 billion years old
c.
3.5 billion years old
d.
1 to 2 billion years old
16.
What process is primarily responsible for the formation of Earth's oceans?
a.
sea-floor spreading
b.
evolution
c.
plate tectonics
d.
outgassing
17.
What is the thermocline?
a.
a transitional layer in the ocean where temperature decreases rapidly with depth
b.
a change in salinity with depth
c.
a layer of cold water in the ocean
d.
the formation of cold water coming from Antarctica
18.
What is at the bottom of the geologic time scale?
a.
the Cenozoic Era
b.
the youngest division of time
c.
the oldest division of time
d.
the Silurian Period
19.
What method is used to determine the exact age of a rock or fossil?
a.
dendrochronology
b.
the principle of superposition
c.
relative age dating
d.
radiometric dating
20.
What is the current era?
a.
Mesozoic
b.
Cenozoic
c.
Paleozoic
d.
Archean
