Question 1

In an unweathered sample of igneous rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

Accepted Answer

A)  200 million years
B)  400 million years
C)  750 million years
D)  1 billion yearsE) A) and D)
F) A) and C)

Question 2

Within the world's sedimentary rocks,fossils ________.

Accepted Answer

A)  are rarely,if ever,found
B)  are randomly distributed
C)  occur in an ordered sequence
D)  are found only in igneous rocksE) None of the above
F) A) and D)

Question 3

Which statement best summarizes the development of the geologic time scale?

Accepted Answer

A)  Numerical ages for rocks were known before the relative sequence of sedimentary layers was established.
B)  Relative ages for sedimentary strata were known before accurate numerical dates for these rocks were measured.
C)  Names of relative ages (such as Silurian) and accurate numerical dates for these ages became known at about the same time.
D)  Numerical ages for fossils were known before the relative sequence of sedimentary layers was established.E) A) and C)
F) A) and B)

Question 4

Uniformitarianism is succinctly summarized by which phrase?

Accepted Answer

A)  The future is the key to the present.
B)  The present is the key to the past.
C)  The past is the key to the present.
D)  The present is the key to the future.E) A) and B)
F) All of the above

Question 5

Which statement about contact #3 is correct?

Accepted Answer

A)  It and contact #2 once formed a continuous unconformity.
B)  It was once elevated farther above contact #2,but faulting has brought them closer together.
C)  It presents an example of an angular unconformity.
D)  It must be younger than the conglomerate,due to the principle of baked contacts.E) A) and B)
F) None of the above

Question 6

Contact #3 is both a ________ and a(n) ________ at various points.

Accepted Answer

A)  conformable contact;unconformity
B)  fault;unconformity
C)  nonconformity;angular unconformity
D)  disconformity;nonconformityE) All of the above
F) None of the above

Question 7

As understood by modern geologists,the principle of uniformitarianism implies that ________.

Accepted Answer

A)  the Earth has always had the same basic appearance that it has today
B)  igneous,metamorphic,and sedimentary rocks are uniformly mixed throughout the crust
C)  physical processes observed today (such as erosion and volcanic eruption) have been active in the past and are preserved in the rock record
D)  physical processes observed today (such as erosion and volcanic eruption) have been occurring throughout Earth history at constant ratesE) A) and B)
F) A) and C)

Question 8

In an unweathered sample of rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

Accepted Answer

A)  200 million years
B)  400 million years
C)  750 million years
D)  1 billion yearsE) B) and D)
F) A) and C)

Question 9

The closure temperature represents the point when ________.

Accepted Answer

A)  a magma cools to the point where minerals begin to crystallize
B)  radioactive isotopes begin to decay
C)  isotopes are no longer free to move out of a crystal lattice
D)  the last remaining magma crystallizesE) A) and B)
F) None of the above

Question 10

Seasonal changes create layering in glaciers known as ________.

Accepted Answer

A)  growth banding
B)  rhythmic layering
C)  seasonal layering
D)  annual bandingE) None of the above
F) B) and D)

Question 11

Two atoms of a single element that differ in number of neutrons are said to represent two distinct ________ of that element.

Accepted Answer

A)  isomers
B)  isotopes
C)  isotherms
D)  atomic speciesE) B) and C)
F) A) and D)

Exam 12: Deep Time: How Old Is Old

Within the world's sedimentary rocks,fossils ________.

Correct Answer
verified

The closure temperature represents the point when ________.

Correct Answer
verified

In an unweathered sample of rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

Correct Answer
verified

Seasonal changes create layering in glaciers known as ________.

Correct Answer
verified

Contact #3 is both a and a(n) at various points.

Correct Answer
verified

Uniformitarianism is succinctly summarized by which phrase?

Correct Answer
verified

Which statement best summarizes the development of the geologic time scale?

Correct Answer
verified

Which statement about contact #3 is correct?

Correct Answer
verified

Two atoms of a single element that differ in number of neutrons are said to represent two distinct ________ of that element.

Correct Answer
verified

As understood by modern geologists,the principle of uniformitarianism implies that ________.

Correct Answer
verified

In an unweathered sample of igneous rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

Correct Answer
verified

Exam 12: Deep Time: How Old Is Old

Within the world's sedimentary rocks,fossils ________.

Correct AnswerverifiedShow Answer

The closure temperature represents the point when ________.

Correct AnswerverifiedShow Answer

In an unweathered sample of rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

Correct AnswerverifiedShow Answer

Seasonal changes create layering in glaciers known as ________.

Correct AnswerverifiedShow Answer

Contact #3 is both a ________ and a(n) ________ at various points.

Correct AnswerverifiedShow Answer

Uniformitarianism is succinctly summarized by which phrase?

Correct AnswerverifiedShow Answer

Which statement best summarizes the development of the geologic time scale?

Correct AnswerverifiedShow Answer

Which statement about contact #3 is correct?

Correct AnswerverifiedShow Answer

Two atoms of a single element that differ in number of neutrons are said to represent two distinct ________ of that element.

Correct AnswerverifiedShow Answer

As understood by modern geologists,the principle of uniformitarianism implies that ________.

Correct AnswerverifiedShow Answer

In an unweathered sample of igneous rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Contact #3 is both a and a(n) at various points.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified