Deck 8: Geologic Time

Question 1

What is the ratio of parent-to-daughter atoms when exactly one half-life has elapsed?

A) 1:1
B) 1:2
C) 1:3

Answer 1

1:1

Question 2

Examine the image below before answering this question. D represents a magma chamber.


-Which relative time principle assumes that G is older than F?

A) Superposition
B) Cross-cutting
C) Original horizontality
D) Inclusions

Answer 2

Superposition

Question 3

Examine the image below before answering this question. D represents a magma chamber.


-Which relative time principle assumes that D is younger than G?

A) Superposition
B) Cross-cutting
C) Original horizontality
D) Inclusions

Answer 3

Cross-cutting

Question 4

Examine the image below before answering this question. D represents a magma chamber.


-What is the correct order of the events from oldest to youngest?

A) D,B,A,G,C,F
B) G,C,F,D,B,A
C) A,B,D,F,G,C
D) F,C,G,A,B,D

Question 5

Carefully examine the relative positions of the lettered arrows on the timeline below and estimate the ages represented by each arrow. Assume all rocks are sedimentary unless otherwise indicated. Use the chart to answer this question.


-Which represents the extinction of the dinosaurs?

A) A
B) B
C) C
D) D
E) E

Question 6

Carefully examine the relative positions of the lettered arrows on the timeline below and estimate the ages represented by each arrow. Assume all rocks are sedimentary unless otherwise indicated. Use the chart to answer this question.


-Which represents the oldest known rocks?

A) A
B) B
C) C
D) D
E) E

Question 7

Carefully examine the relative positions of the lettered arrows on the timeline below and estimate the ages represented by each arrow. Assume all rocks are sedimentary unless otherwise indicated. Use the chart to answer this question.


-Which represents the Cambrian explosion?

A) A
B) B
C) C
D) D
E) E

Question 8

Use the diagram below to answer the questions that follow.


-Which represents rocks that formed before A but after E?

A) F
B) G
C) C
D) D
E) E

Question 9

Use the diagram below to answer the questions that follow.


-Which represents rocks composed of granite and is older than F?

A) A
B) H
C) C
D) D
E) E

Question 10

Use the diagram below to answer the questions that follow.


-Which represents a sedimentary rock that did not experience contact metamorphism?

A) A
B) B
C) C
D) D
E) E

Question 11

Using the diagram below, what is the possible age of F if A is 100 million years old and D is 70 million
years old?

A) 85 M yrs
B) 170 M yrs
C) 55 M yrs
D) 110 M yrs

Question 12

Which graph below best represents the change in the proportion of unstable (parent) radioactive isotopes
with time?

A) Graph a
B) Graph b
C) Graph c
D) Graph d

Question 13

Which geologic time principle places events in order based on their position?

A) Relative time
B) Numerical time
C) Deep time

Question 14

Which geologic time principle states that older geologic units are below younger geologic units?

A) Principle of superposition
B) Principle of cross cutting relations
C) Principle of original horizontality

Question 15

Why did Steno propose what eventually became known as the principle of original horizontality?

A) To defend Biblical accounts for the formation of the earth.
B) To explain the existence of fossils found in rocks he was studying.
C) To explain that the earth must be very old based on his observations.

Question 16

Why did Hutton propose what eventually became known as the principle of superposition?

A) To defend Biblical accounts for the formation of the earth.
B) To explain the existence of fossils found in rocks he was studying.
C) To explain that the earth must be very old based on his observations.

Question 17

What must be true of a rock unit that is cut by an igneous intrusion?

A) The rock unit is the same age as the intrusion.
B) The rock unit is younger than the intrusion.
C) The rock unit is older than the intrusion.

Question 18

What must be true of a rock unit has an inclusion?

A) The rock unit is the same age as the inclusion.
B) The rock unit is younger than the inclusion.
C) The rock unit is older than the inclusion.

Question 19

Which relative dating principles can be observed in the Grand Canyon?

A) Superposition
B) Original horizontality
C) Cross cutting
D) All of the above

Question 20

What type of scientist studies fossils?

A) Paleontologist
B) Geomorphologist
C) Petrologist

Question 21

When were the key ingredients for life first present on Earth?

A) 4,000 years ago
B) 4 million years ago
C) 4 billion years ago

Question 22

How is the geologic time scale sub-divided into smaller units?

A) Based on equal time intervals
B) Based on major events in Earth history
C) Based on the fossil record

Question 23

When did large numbers of fossils first appear in the geologic record?

A) About 5000 years ago
B) About 500 million years ago
C) About 5 billion years ago

Question 24

When did dinosaurs, exclusive of birds, become extinct?

A) 6,600 years ago
B) 6.6 million years ago
C) 66 million years ago
D) 660 million years ago

Question 25

When did over 96% of marine and 70% of land species on Earth become extinct?

A) K-T boundary
B) P-T boundary
C) T-C boundary

Question 26

What happens to the parent isotope over time?

A) It increases
B) It decreases
C) It stays the same

Question 27

Why can radioactive elements be used to determine the ages of rocks?

A) Their half lives increase predictably over time.
B) Their half lives decrease predictably over time.
C) Their half lives do not change over time.

Question 28

Acceptance of the concept of deep time was a paradigm shift for the scientific community.

Question 29

Relative dating involves radioactive isotopes.

Question 30

The geologic time scale was originally developed using relative time principles and fossil correlation.

Question 31

The principle of superposition suggests that rock layers on the top of a sequence are older than layers on the bottom.

Question 32

Deep time refers to the amount of time primarily before humans evolved.

Question 33

Tom Vail and the Tavwoats Indians both appeal to a mystical force rather than science when discussing the formation of the Grand Canyon.

Question 34

James Ussher was a religious scholar who first suggested an exact date for "creation"
of the Earth.

Question 35

A fault would be a cross-cutting feature.

Question 36

Rocks at the bottom of a sequence cannot be deformed if overlying rocks are not deformed.

Question 37

The frequently found progression from sandstone to shale to limestone is typical of that found along passive margins today.

Question 38

Cinder cones are typically the last formation in a geologic sequence.

Question 39

Fossils are the key to matching rocks across large regions.

Question 40

Changes to the biosphere were most common 3.5 billion years ago.

Question 41

Periods are the longest time spans on the Geologic Time Scale.

Question 42

Fossils became common starting with the Cambrian.

Question 43

Atmospheric oxygen greatly increased during the Cambrian.

Question 44

Paleontologists have examined the fossil record to determine that 99.9% of all species that ever existed have become extinct.

Question 45

Humans have existed on Earth longer than any other animal species.

Question 46

Humans and non-avian dinosaurs co-existed for a short amount of time.

Question 47

The Age of Mammals followed the K-T mass extinction.

Question 48

A single ocean existed when Pangaea formed.

Question 49

The only geologic event known to correlate with the P-T mass extinction is an asteroid impact.

Question 50

Radioactive isotope dating techniques are usually used for sedimentary rocks.

Question 51

Early calculations for the age of the Earth were similar to those determined using radioactive isotopes.

Question 52

The atomic mass number is found by adding the number of protons and neutrons in the nucleus.

Question 53

Radioactive isotopes disappear when they decay.

Question 54

Radioactive elements are found in materials all around us, even our bodies.

Question 55

A half-life is defined as half the time it takes for a group of isotopes to decay to daughters.

Question 56

Numerical dating and relative time principle can be used to bracket ages of sedimentary rocks.

Question 57

Uniformitarian principles assume that features on Earth's surface formed as a result of isolated cataclysms of relatively short duration similar to those observed today.

Question 58

Catastrophic events must have precedents.