Deck 21: Geologic Time

Question 1

The principle of uniformity requires you to believe that the geologic features you see today were formed in the past by the same processes we observe today.

Answer 1

True

Question 2

Estimations of the age of Earth based on its present rate of cooling from a molten mass yielded times that are close to current estimates.

Answer 2

False

Question 3

Which of the following is not a common way for fossils to form?

A)preservation of skeletal remains
B)preservation of an organism's shape
C)preservation of signs of activity
D)preservation of soft parts by entombment in amber

Answer 3

D

Question 4

Fossils are useful for all of the following except

A)correlating rocks in one location with those in another.
B)determining the former environment of a region.
C)determining the former climate of a region.
D)determining the exact age of Earth.

Question 5

The fossilization process by which the original material is dissolved and new materials added is called

A)replacement.
B)carbonization.
C)mineralization.
D)replication.

Question 6

Index fossils are fossils of distinctive plant or animal species that lived in a specific location for a long time.

Question 7

The science of deciphering the history of life from the fossil record is called archeology.

Question 8

Which is likely to be the oldest rock in the formation?

A)sandstone
B)shale
C)limestone
D)basalt

Question 9

Correlating and relative dating of rock units is made possible by application of the principle of

A)cross-cutting relationships.
B)faunal succession.
C)superposition.
D)All of the above.

Question 10

It took a long time before people recognized the connection between fossils and living organisms.

Question 11

A road cut shows layers of sedimentary rock that are uptilted.From this observation one could conclude that the rocks

A)have been subjected to deformational stress.
B)were formed by deposition of sediment on a sloping surface.
C)were formed on land instead of under water.
D)None of the above.

Question 12

Faults, folds, and igneous intrusions are always younger than the rock layers in which they are found.

Question 13

Fossils are generally best preserved in metamorphic rock layers.

Question 14

Evidence for the presence of an unconformity in the formation below is given by

A)the uptilting of the beds in layer 1.
B)the erosion that must have taken place at the boundary of 1 and 2.
C)the new sediment type deposited at the boundary of 2 and 3.
D)All of these are example of unconformities.

Question 15

Minerals replaced the wood in trees over a very long period making petrified wood.

Question 16

Lack of fossils in Pre-Cambrian rocks means that very little life existed in this era.

Question 17

Which of the following descriptions of this formation is most likely?

A)The limestone and shale layers were deposited on the slope of a mountain.
B)The basalt is crystallized magma that nearly reached the sandstone layer.
C)The limestone and shale layers were eroded long before the sandstone was deposited.
D)All of these descriptions are possible.

Question 18

The diagram below illustrates which of the following principles?

A)principle of uniformity
B)principle of superposition
C)principle of original horizontality
D)principle of cross-cutting

Question 19

Reptiles were the dominant life form in the Mesozoic Era.

Question 20

The oldest fossils are about how many years old?

A)4.5 billion years
B)3.5 billion years
C)250 million years
D)10,000 years

Question 21

The dominant life forms in the Cambrian period were

A)dinosaurs.
B)amphibians.
C)trilobites and brachiopods.
D)algae and bacteria.

Question 22

The process that has yielded the most accurate estimate of the age of Earth is measurement of

A)the rate of sedimentation.
B)the radioactive decay of elements in minerals.
C)rate of increase of salinity of the oceans.
D)the rate of the cooling of Earth from a molten mass.

Question 23

The Geologic Time Scale defines eras in terms of

A)major worldwide extinctions of life on Earth.
B)reversals in Earth's magnetic field.
C)the beginning of the radioactive decay of elements in minerals.
D)major plate tectonic events.

Question 24

Correlation and relative dating through the use of index fossils is limited because

A)index fossils are extremely rare.
B)many sedimentary layers do not contain index fossils at all.
C)index fossils appeared for too short a time in the geologic record to be very helpful.
D)index fossils are rarely found in other than sedimentary rocks.

Question 25

To serve as a geologic clock, a process must

A)have been operating since the beginning of Earth.
B)be uniform (or at least subject to averaging).
C)be capable of being measured.
D)All of the above.

Question 26

If you were hunting dinosaur fossils, you would be examining rocks from which era?

A)Precambrian
B)Paleozoic
C)Mesozoic
D)Cenozoic

Question 27

You would expect to find fossils that most closely resembled current life forms in rocks from which era?

A)Precambrian
B)Paleozoic
C)Mesozoic
D)Cenozoic

Question 28

Which of the following statements about the granite in center of the formation below is false?

A)The granite is a crystallized intrusion of magma.
B)The granite formed after the sedimentary layers were deposited.
C)The intrusion of the magma probably produced some metamorphism in the
D)sedimentary layers.
E)The sedimentary layers formed later, burying the granite outcrop.

Question 29

The Cenozoic is known as the Age of the

A)Mammals.
B)Dinosaurs.
C)Amphibians.
D)Algae.

Question 30

The Rocky Mountains

A)were uplifted about the time the dinosaurs died out.
B)are older than the Appalachian Mountains.
C)formed when Pangaea began to break up.
D)are more than 200 million years old.