Question 1

Uniformitarianism is succinctly summarized by which phrase?
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.

Accepted Answer

Uniformitarianism is the idea that the present geological processes that we observe today also occurred in the past at the same rate and intensity, and hence the past can be understood by observing the present. Therefore, the present is the key to the past.

Question 2

Which of the following geologic principles is a direct result of gravity?
A)baked contacts
B)cross-cutting relationships
C)original horizontality
D)inclusions

Accepted Answer

Original horizontality is the geologic principle stating that sediments settle in horizontal layers due to the force of gravity.

Question 3

Magma has intruded into some limestone,and a marble rind formed surrounding the granite pluton.The marble rind must be younger than the limestone according to the principle of ________.
A)superposition
B)baked contacts
C)original horizontality
D)original continuity

Accepted Answer

The principle of baked contacts states that when an igneous intrusion comes in contact with preexisting rock, the heat from the magma alters the texture and composition of the surrounding rock. In this case, the intrusion of magma has altered the limestone and created a marble rind around the pluton, indicating that the marble rind is younger than the limestone.

Question 4

If the relative ages of two formations are known,what else about them can be inferred?
A)their absolute ages
B)their fossil assemblages
C)their lithologies
D)their relative position in a sequence of rock layers

Accepted Answer

Knowing the relative ages of two formations allows us to infer their relative position in a sequence of rock layers. This means we can determine which formation is older or younger than the other based on their position in the rock record. However, we cannot determine their absolute ages or fossil assemblages without additional information. Lithologies (rock types) may vary within and between formations and are not necessarily linked to their relative ages.

Question 5

If a sandstone lies on top of a shale,________.
A)the shale must be older,according to the principle of superposition
B)the sandstone must be older,according to the principle of superposition
C)the shale must be older,according to the principle of components
D)their relative ages cannot be determined from the information given

Accepted Answer

The principle of superposition states that in an undisturbed sequence of sedimentary rock layers, the oldest layers are at the bottom and the youngest layers are at the top. Therefore, the shale (which is at the bottom) must be older than the sandstone (which is on top).

Question 6

In an undisturbed sequence of sedimentary rocks,younger layers overlie older layers,according to the principle of ________. 
A)superposition
B)original continuity
C)original horizontality
D)uniformitarianism

Accepted Answer

The principle of superposition states that in an undisturbed sequence of sedimentary rocks, younger layers overlie older layers.

Question 7

Which principle of stratigraphy could be used to determine the relative ages of Layer 7 and Layer 3? 
A)the principle of fossil succession
B)the principle of original horizontality
C)the principle of lateral continuity
D)the principle of inclusions

Accepted Answer

The principle of fossil succession states that fossil organisms succeed one another in a definite and predictable order, so by examining the fossils in Layers 7 and 3, we can determine their relative ages. Choice B, the principle of original horizontality, would be relevant if we needed to determine whether the layers had been disturbed or tilted since their deposition. Choice C, the principle of lateral continuity, would be relevant if we needed to determine whether the two layers were once continuous and have since been separated by erosion. Choice D, the principle of inclusions, would be relevant if we needed to determine whether the materials within the two layers were derived from the same source.

Question 8

Basaltic clasts within the basal layers of a conglomerate imply which of the following statements? 
A)The conglomerate must be the older of the two.
B)The basalt must be the older of the two.
C)The section must not have been overturned by tectonic activity at any time.
D)The basalt intruded into the conglomerate.

Accepted Answer

Basaltic clasts within a conglomerate imply that the basalt existed before the conglomerate was formed, and therefore the basalt must be older than the conglomerate. This conclusion can be drawn regardless of whether the section has been overturned or not. The presence of basaltic clasts does not provide any information about the relative ages of the two rocks, so options A) and D) are incorrect.

Question 9

Concerning the relative ages of the granite and sandstone,________. 
A)the granite must be older,according to the principle of superposition
B)the sandstone must be older,according to the principle of superposition
C)the granite must be older,according to the principle of components
D)their relative ages cannot be determined from the information given

Accepted Answer

The principle of superposition states that in a sequence of sedimentary rock layers, the oldest layer is at the bottom and the youngest layer is at the top. However, there is no information given about the sequence or location of the granite and sandstone, so their relative ages cannot be determined. The principle of components is not relevant in this context.

Question 10

Which of the following geologic principles is NOT a result of gravity?
A)original horizontality
B)cross-cutting relationships
C)original continuity
D)superposition

Accepted Answer

Cross-cutting relationships are a result of rock deformation or intrusion, not gravity. Original horizontality, original continuity, and superposition are all aspects of gravity's influence on sedimentary layers.

Question 11

If the lithology and fossil content of two bodies of rock on opposite sides of a canyon are identical,then these remaining outcrops were likely physically connected at one time and formed part of an extensive,sheet-like layer of rock.This idea summarizes the principle of ________. 
A)superposition
B)original continuity
C)original horizontality
D)uniformitarianism

Accepted Answer

The principle of original continuity states that layers of sediment initially extend laterally in all directions before they terminate, either by thinning at the edges of their basin of deposition, by interfingering with another sediment type or by Grade out. As the lithology and fossil content of two bodies of rock on opposite sides of a canyon are identical, it suggests that these outcrops were physically connected and formed part of an extensive, sheet-like layer of rock. Thus, this idea summarizes the principle of original continuity.

Question 12

If a basalt body cuts across a fault,what are the relative ages of the basalt and the fault?
A)The fault must be older,according to the principle of cross-cutting relationships.
B)The basalt must be older,according to the principle of cross-cutting relationships.
C)The basalt must be older,according to the principle of original horizontality.
D)Their relative ages cannot be determined from the information given.

Accepted Answer

According to the principle of cross-cutting relationships, the feature that cuts across another feature must be younger than the feature it cuts through. Therefore, the fault must be older than the basalt body that cuts across it.

Question 13

If an igneous dike cuts across a sequence of sedimentary beds,________.
A)the beds must be older
B)the dike must be older
C)the beds and the dike must have formed at the same time
D)their relative ages cannot be determined from the information given

Accepted Answer

According to the principle of cross-cutting relationships, the igneous dike must be younger than the sedimentary beds it cuts across, indicating that the beds are older.

Question 14

Within the world's sedimentary rocks,fossils ________.
A)are rarely,if ever,found
B)are randomly distributed
C)occur in an ordered sequence
D)are found only in igneous rocks

Accepted Answer

Fossils in sedimentary rocks occur in an ordered sequence, known as the fossil record, where younger rocks contain more recent and differentiated life forms while older rocks contain fossils of simpler organisms. This sequence helps in understanding the evolution of life on Earth.

Question 15

The principle of ________ explains the occurrence of older rock within a newer igneous body.
A)baked contacts
B)cross-cutting relationships
C)original horizontality
D)inclusions

Accepted Answer

The principle of inclusions states that rock fragments present within a host rock are older than the host rock itself. Therefore, it can explain the occurrence of older rock within a newer igneous body.

Question 16

James Hutton,the "father of geology," put forth the principle of ________.
A)superposition
B)original continuity
C)original horizontality
D)uniformitarianism

Accepted Answer

James Hutton is known for developing the principle of uniformitarianism, which states that the processes that shape the Earth's surface today have been occurring in the same way throughout geologic time. This principle laid the foundation for modern geology.

Question 17

In the area immediately surrounding an igneous intrusion,a host limestone is locally metamorphosed to produce marble.Which of the following statements is correct?
A)The intrusive igneous rock must be older than the limestone.
B)The limestone must be older than the marble.
C)The marble must be older than the intrusive rock.
D)The relative ages of the three units cannot be determined with the information given.

Accepted Answer

The process of metamorphism occurs after the formation of a pre-existing rock, meaning that the limestone must have been formed first. The intrusion then came later and caused localized metamorphism in the surrounding area, resulting in the formation of marble. Therefore, option B is correct. Option A is incorrect because there is no information to suggest that the intrusive rock is older. Option C is incorrect because the marble is a product of metamorphism and is therefore younger than the limestone. Option D is incorrect because the relative ages can be determined based on the sequence of events.

Question 18

Based on the figure,what is the age of Layer 7 relative to Layer 3? 
A)Layer 7 is younger than Layer 3.
B)Layer 7 is older than Layer 3.
C)Layer 7 and Layer 3 are the same rock type,so they are the same age.
D)Their relative ages cannot be determined

Accepted Answer

The answer of Based on the figure,what is the age...

Question 19

The oldest geologic unit is ________. 
A)Layer 1
B)Layer 8
C)Layer 5
D)Layer 10

Accepted Answer

The answer of The oldest geologic unit is ________. 
A)Layer...

Question 20

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

Accepted Answer

The principle of uniformitarianism suggests that the same natural processes we observe today have been occurring throughout Earth's history, allowing us to interpret past geological events.

Quiz 12: Deep Time: How Old Is Old

Uniformitarianism is succinctly summarized by which phrase?

Which of the following geologic principles is a direct result of gravity?

Magma has intruded into some limestone,and a marble rind formed surrounding the granite pluton.The marble rind must be younger than the limestone according to the principle of ________.

If the relative ages of two formations are known,what else about them can be inferred?

If a sandstone lies on top of a shale,________.

In an undisturbed sequence of sedimentary rocks,younger layers overlie older layers,according to the principle of ________.

Which principle of stratigraphy could be used to determine the relative ages of Layer 7 and Layer 3?

Basaltic clasts within the basal layers of a conglomerate imply which of the following statements?

Concerning the relative ages of the granite and sandstone,________.

Which of the following geologic principles is NOT a result of gravity?

If the lithology and fossil content of two bodies of rock on opposite sides of a canyon are identical,then these remaining outcrops were likely physically connected at one time and formed part of an extensive,sheet-like layer of rock.This idea summarizes the principle of ________.

If a basalt body cuts across a fault,what are the relative ages of the basalt and the fault?

If an igneous dike cuts across a sequence of sedimentary beds,________.

Within the world's sedimentary rocks,fossils ________.

The principle of ________ explains the occurrence of older rock within a newer igneous body.

James Hutton,the "father of geology," put forth the principle of ________.

In the area immediately surrounding an igneous intrusion,a host limestone is locally metamorphosed to produce marble.Which of the following statements is correct?

Based on the figure,what is the age of Layer 7 relative to Layer 3?

The oldest geologic unit is ________.

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