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.

Accepted Answer

The principle of uniformity, also known as the principle of uniformitarianism, states that the same geologic processes we see happening today have been at work throughout Earth's history. This principle is a fundamental concept in geology and has been used to understand the formation of the Earth's surface features.

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.

Accepted Answer

Early estimations of Earth's age based on its cooling rate were significantly shorter than current estimates, which are based on radiometric dating techniques and suggest an age of about 4.54 billion years. Cooling rate estimates did not account for heat produced by radioactive decay, leading to underestimations.

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

Accepted Answer

Preservation of soft parts by entombment in amber is a rare way for fossils to form. The other options listed (preservation of skeletal remains, preservation of an organism's shape, preservation of signs of activity) are all common ways for fossils to form.

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.

Accepted Answer

Fossils can be used to determine the relative age of rocks and the sequence of events in Earth's history, but they cannot be used to determine the exact age of Earth. This is typically done through radiometric dating of rocks and minerals.

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.

Accepted Answer

Replacement is the fossilization process where the original material of an organism is dissolved and new mineral materials are deposited in its place, effectively creating a replica of the original organism in a different material.

Question 6

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

Accepted Answer

Index fossils are fossils of organisms that were geographically widespread but lived during a relatively short period of time, making them useful for dating the rocks in which they are found.

Question 7

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

Accepted Answer

The science of deciphering the history of life from the fossil record is called paleontology, not archeology. Archeology is the study of human history and prehistory through artifacts and physical remains.

Question 8

-Which is likely to be the oldest rock in the formation?
A)sandstone
B)shale
C)limestone
D)basalt

Accepted Answer

Limestone is usually formed from the accumulation of marine fossils such as shells and coral, which can date back hundreds of millions of years. Sandstone, shale, and basalt can also be old rocks, but their ages can vary depending on the specific geological processes that formed them.

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.

Accepted Answer

The principle of cross-cutting relationships, faunal succession, and superposition are all used in correlating and relative dating of rock units. The principle of cross-cutting relationships states that any rock or feature that cuts across another rock or feature is younger than the rock or feature it cuts across. Faunal succession is based on the observation that assemblages of fossils in rocks change over time, and can be used to correlate and date rock units. The principle of superposition states that in an undisturbed sequence of sedimentary rocks, the oldest rocks are at the bottom and the youngest rocks are at the top. By using these principles, geologists can determine the relative ages of rocks and their relationships to one another.

Question 10

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

Accepted Answer

It wasn't until the 18th century that people began to understand that fossils were once living organisms and not just rocks or mineral formations.

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.

Accepted Answer

The uptilting of sedimentary rock layers shows that they have been subjected to deformational stress, likely through tectonic activity or faulting. This is a common process that can cause sedimentary rocks to become uplifted and tilted. B and C are possible explanations for other rock formations, but they do not necessarily apply to uptilted sedimentary rocks specifically.

Question 12

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

Accepted Answer

According to the principle of cross-cutting relationships in geology, faults, folds, and igneous intrusions must be younger than the rock layers they cut through or deform.

Question 13

Fossils are generally best preserved in metamorphic rock layers.

Accepted Answer

Fossils are generally best preserved in sedimentary rock layers due to the deposition of sediment and the subsequent burial and preservation of organic material. Metamorphic rock, on the other hand, is formed from the alteration of pre-existing rock through heat and pressure, which can often destroy or alter any fossils present.

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.

Accepted Answer

An unconformity is a time gap in the rock record that occurs when rocks are eroded or not deposited for a period of time. Option B describes the erosion that must have taken place at the boundary between layers 1 and 2, which is evidence of a time gap or unconformity. The uptilting of the beds in layer 1 (option A) and the new sediment type deposited at the boundary of 2 and 3 (option C) do not necessarily indicate an unconformity, but could be due to other geological processes. Option D is not a valid choice because only option B provides evidence for an unconformity.

Question 15

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

Accepted Answer

Petrified wood is formed over long periods of time as the organic material in trees is replaced by minerals such as silica, calcite, and pyrite. This process is called permineralization and results in a fossilized version of the original tree, with the same structure and shape, but made entirely of minerals.

Question 16

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

Accepted Answer

The lack of fossils in Pre-Cambrian rocks does not necessarily mean that very little life existed in this era. It could be due to poor preservation or the lack of hard body parts that are more likely to fossilize. Recent studies have shown evidence of microbial life in Pre-Cambrian rocks, indicating that there was at least some life present during this time period.

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.

Accepted Answer

The answer of 
-Which of the following descriptions of this...

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

Accepted Answer

The diagram shows sedimentary layers that are all parallel and horizontal. This illustrates the principle of original horizontality, which states that layers of sediment are generally deposited in a horizontal or nearly horizontal position.

Question 19

Reptiles were the dominant life form in the Mesozoic Era.

Accepted Answer

Reptiles, including dinosaurs, pterosaurs, and marine reptiles, were the dominant life form during the Mesozoic Era, which lasted roughly from 252 million years ago to 66 million years ago.

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

Accepted Answer

The oldest fossils found so far are about 3.5 billion years old. A is incorrect because that is the age of the Earth, not the oldest fossils. C is incorrect because 250 million years is the age of some dinosaur fossils, not the oldest fossils overall. D is incorrect because 10,000 years is relatively recent in geological time and not even close to the age of the oldest fossils.

Quiz 21: Geologic Time

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.

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.

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

Fossils are useful for all of the following except

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

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

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

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

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

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

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

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

Fossils are generally best preserved in metamorphic rock layers.

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

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

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

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

The diagram below illustrates which of the following principles?

Reptiles were the dominant life form in the Mesozoic Era.

The oldest fossils are about how many years old?