1.
What are the basic differences between the disciplines of
physical and historical geology?
Correct Answer
B. Historical geology involves the study of rock strata, fossils,
and geologic events, utilizing geologic time scale as a
reference; pHysical geology includes the study of how rocks form and of how erosion shapes the land surface.
Explanation
The correct answer explains that historical geology focuses on studying rock strata, fossils, and geologic events using the geologic time scale as a reference. On the other hand, physical geology examines how rocks form and how erosion shapes the land surface. This explanation clearly distinguishes the basic differences between the two disciplines, highlighting their respective areas of study.
2.
Which of the following best describes the fundamental
concept of superposition?
Correct Answer
D. Any sedimentary deposit accumulates on older rock or
sediment layers.
Explanation
The concept of superposition in geology states that in any sequence of undisturbed sedimentary rocks, the youngest rocks are at the top and the oldest rocks are at the bottom. This means that any new sedimentary deposit will accumulate on top of older rock or sediment layers. This principle is used to determine the relative ages of rocks and fossils in stratigraphy.
3.
Active mountain belts are most likely to be found ________.
Correct Answer
A. Along the margins of continents
Explanation
Active mountain belts are most likely to be found along the margins of continents because this is where tectonic plate boundaries are located. The collision or subduction of these plates leads to the formation of mountain ranges. Along the margins of continents, there are often convergent plate boundaries where two plates are colliding, such as the Himalayas along the margin of the Indian subcontinent and the Andes along the margin of South America. These active mountain belts are characterized by intense tectonic activity, including earthquakes and volcanic eruptions.
4.
All of the following observations and conclusions are
consistent with the concept of “uniformitarianism” except
______.
Correct Answer
E. An erupting volcano proves that burning subterranean coal
beds provide the heat
5.
______ was an important 18th-century English
geologist and proponent of Uniformitarianism.
Correct Answer
D. James Hutton
Explanation
James Hutton was an important 18th-century English geologist and proponent of Uniformitarianism. His work laid the foundation for modern geology and greatly influenced the understanding of Earth's history and the processes that shape it. Hutton's principles of Uniformitarianism, which state that the same geological processes that operate today have been at work throughout Earth's history, challenged the prevailing belief in catastrophism and provided a more comprehensive and gradualistic explanation for the formation of the Earth's features. His contributions revolutionized the field of geology and paved the way for further scientific discoveries in the study of the Earth's history.
6.
If the Precambrian eon accounts for 88% of the geologic time
scale, why is it one of the smallest boxes in Figure 1.8 in this
chapter?
Correct Answer
C. Because cepHalopods were dominant in that eon
7.
Rocks are ________.
Correct Answer
D. Aggregates of one or more minerals
Explanation
Rocks are aggregates of one or more minerals. This means that rocks are made up of different minerals that are combined together. They can contain a single mineral or a combination of multiple minerals. The minerals in a rock can vary in their composition and properties, giving each rock its unique characteristics.
8.
What is the source of the energy that powers the Earth
system?
Correct Answer
C. Both A and B
Explanation
The correct answer is both A and B. The Sun is a major source of energy for the Earth system. It provides heat and light energy through processes like nuclear fusion. Additionally, heat from Earth's interior, generated by the decay of radioactive elements and residual heat from its formation, also powers the Earth system. Both sources of energy play crucial roles in shaping the Earth's climate, weather patterns, and geological processes.
9.
All of the following are possible steps of scientific
investigation except _________.
Correct Answer
B. The assumption of conclusions without prior experimentation
or observation
Explanation
The correct answer is "the assumption of conclusions without prior experimentation or observation." This is because scientific investigation is based on empirical evidence, which requires observations and experiments to gather data and draw conclusions. The assumption of conclusions without prior experimentation or observation goes against the scientific method and the principles of evidence-based inquiry.
10.
Which one of the following most accurately describes the
volcanoes of the Hawaiian Islands?
Correct Answer
B. Shield volcanoes fed by a long-lived hot spot below the Pacific
lithospHeric plate
Explanation
The Hawaiian Islands are primarily composed of shield volcanoes, which are formed by the eruption of low-viscosity lava that flows easily over long distances. This type of volcanic activity is typically associated with hot spots, which are areas of intense volcanic activity caused by a mantle plume that rises from deep within the Earth. The hot spot beneath the Pacific lithospheric plate has been active for millions of years, resulting in the formation of the Hawaiian Islands. Therefore, the correct answer is "Shield volcanoes fed by a long-lived hot spot below the Pacific lithospheric plate."
11.
The modern-day Red Sea is explained by plate tectonics
theory because it is ____________.
Correct Answer
C. A rift zone that may eventually open into a major ocean if Arabia and Africa continue to separate
Explanation
The modern-day Red Sea is explained by plate tectonics theory because it is a rift zone that may eventually open into a major ocean if Arabia and Africa continue to separate. This means that the Red Sea is formed by the pulling apart of the Arabian and African continental plates, creating a rift where new oceanic crust is being formed. If the separation continues, the rift zone may widen and eventually lead to the formation of a new ocean.
12.
Why is so much basaltic magma erupted along mid-ocean
ridges?
Correct Answer
B. Lowered pressures decrease the temperatures at which
basalt magma can partially melt from a rising plume of
mantle peridotite
Explanation
The correct answer is that lowered pressures decrease the temperatures at which basalt magma can partially melt from a rising plume of mantle peridotite. This means that as the mantle material rises closer to the surface along the mid-ocean ridge, the decrease in pressure allows for the partial melting of the peridotite, resulting in the eruption of basaltic magma. This process is known as decompression melting.
13.
Which of the following best describes Hess' hypothesis of
seafloor spreading?
Correct Answer
C. Rising material in the mantle spreads laterally carrying the seafloor away from seafloor ridges in the center of the ocean
basin.
Explanation
Hess' hypothesis of seafloor spreading proposes that the seafloor is spreading laterally away from seafloor ridges in the center of the ocean basin. This is due to the rising material in the mantle, which spreads laterally and carries the seafloor away from these ridges. This hypothesis explains the formation of new oceanic crust and the movement of tectonic plates.
14.
Why did people not believe Wegener’s idea ?
Correct Answer
A. He failed to provide a mechanism
Explanation
Wegener's idea of continental drift was not initially believed because he did not provide a mechanism to explain how the continents moved. Without a clear explanation of the forces or processes that caused the movement, scientists were skeptical of his theory. While Wegener did present evidence such as fossil plants and ferns, which suggested that continents were once connected, the lack of a mechanism made it difficult for others to accept his idea.
15.
What happens when two continental plates collide?
Correct Answer
C. One of the plates may be forced under the other slightly, but no subduction takes place
Explanation
When two continental plates collide, one of the plates may be forced under the other slightly, but no subduction takes place. This means that one plate is pushed beneath the other, but it does not sink into the mantle. Instead, the collision causes the crust to buckle and fold, forming mountain ranges. This process is known as continental collision and is responsible for the formation of features like the Himalayas.
16.
How can the discovery of coal in cold and dry Antarctica be
explained?
Correct Answer
B. Antarctica was once part of the “supercontinent” Pangaea and
was in a warm and humid climate which allowed the formation of
coal.
Explanation
The correct answer suggests that coal was formed in Antarctica when it was part of the "supercontinent" Pangaea and in a warm and humid climate. This explanation aligns with the geological understanding that coal is formed from the remains of ancient plants and organic matter that accumulate in swamps and marshes over millions of years. Therefore, when Antarctica was in a warm and humid climate, it provided the necessary conditions for the formation of coal.
17.
What happens at divergent boundaries?
Correct Answer
A. The seafloor spreads and magma rises up to fill the gap, forming
underwater features like oceanic ridges and submarine
volcanoes
Explanation
At divergent boundaries, the seafloor spreads apart, creating a gap. This process is known as seafloor spreading. As the plates move apart, magma from the mantle rises up to fill the gap. This magma cools and solidifies to form new oceanic crust. This continuous process of seafloor spreading leads to the formation of underwater features such as oceanic ridges and submarine volcanoes. These features are evidence of the tectonic activity occurring at divergent boundaries.
18.
The _______ is an example of an active, continent-continent
collision.
Correct Answer
B. Northward movement of India into Eurasia
Explanation
The collision between the Indian plate and the Eurasian plate is an example of an active, continent-continent collision. The northward movement of India towards Eurasia has resulted in the formation of the Himalayas, one of the largest mountain ranges in the world. This collision has caused the crust to buckle and fold, leading to the uplift of the Himalayas. The collision is ongoing and continues to shape the landscape of the region.
19.
The composition of the core of the Earth is thought to be
___________.
Correct Answer
C. Iron-Nickel alloy
Explanation
The composition of the core of the Earth is thought to be an Iron-Nickel alloy. This is based on various scientific studies and evidence, including seismic data and the behavior of Earth's magnetic field. The core is believed to consist mainly of iron, with a smaller amount of nickel. This composition is consistent with the dense nature of the core and its ability to generate a magnetic field. Other options like basalt, peridotite, and granite are not likely to be present in the core due to their different chemical compositions and densities.
20.
Which of the following best defines a mineral and a rock?
Correct Answer
C. In a mineral the constituent atoms are bonded in a regular,
repetitive, internal structure; a rock is a lithified or
consolidated aggregate of different mineral grains.
Explanation
A mineral is defined as having constituent atoms bonded in a regular, repetitive, internal structure, while a rock is defined as a lithified or consolidated aggregate of different mineral grains. This means that minerals have a specific arrangement of atoms, whereas rocks are made up of various minerals that are bonded together.
21.
Atoms of the same element, carbon for example, have the
same number of________.
Correct Answer
D. Proton in the nucleus
Explanation
Atoms of the same element, carbon for example, have the same number of protons in the nucleus. This is because the number of protons in an atom determines its atomic number, which is unique to each element. Therefore, all carbon atoms will have the same number of protons in their nuclei, regardless of their isotopes or other factors.
22.
Which of the following best characterizes ferromagnesian
silicates?
Correct Answer
C. They are black to dark-green silicate minerals containing iron and magnesium
Explanation
The correct answer states that ferromagnesian silicates are black to dark-green silicate minerals containing iron and magnesium. This means that these minerals have a dark color and contain both iron and magnesium as essential components. The other options are incorrect because they either do not mention the presence of iron and magnesium or describe different colors and compositions.
23.
What element is the most abundant in Earth’s crust by
weight?
Correct Answer
C. Oxygen
Explanation
Oxygen is the most abundant element in Earth's crust by weight. It makes up about 46% of the Earth's crust, followed by silicon at 28%. Oxygen is found in various minerals such as silicates, oxides, and carbonates. It is also a major component of water, which covers about 71% of the Earth's surface. Oxygen is essential for supporting life and plays a crucial role in many geological and chemical processes on Earth.
24.
The resistance of a mineral to abrasion is known as
________.
Correct Answer
D. Hardness
Explanation
The resistance of a mineral to abrasion refers to its hardness. Hardness is a measure of how easily a mineral can be scratched or damaged. It is determined by the strength of the chemical bonds within the mineral's structure. Therefore, the correct answer is hardness.
25.
The strong tendency of certain minerals to break along
smooth, parallel planes is known as ________.
Correct Answer
B. Cleavage
Explanation
Cleavage is the correct answer because it refers to the strong tendency of certain minerals to break along smooth, parallel planes. This property is commonly observed in minerals with a crystalline structure, where the atomic arrangement allows for the formation of these planes of weakness. Cleavage can result in the formation of flat, smooth surfaces on minerals, which can be useful in their identification and classification.
26.
Which one does not correctly describe a mineral?
Correct Answer
C. It can be liquid or solid
Explanation
The statement "It can be liquid or solid" does not correctly describe a mineral. Minerals are naturally occurring substances that have a specific and predictable chemical composition and a specific internal crystal structure. They can be identified by their characteristic physical properties such as color, hardness, and density. However, minerals cannot be liquid as they are solid substances.
27.
Which are the most abundant minerals in the Earth’s crust
and mantle?
Correct Answer
D. Silicates
Explanation
Silicates are the most abundant minerals in both the Earth's crust and mantle. Silicates are compounds that contain silicon and oxygen, along with other elements like aluminum, iron, calcium, and magnesium. These minerals make up a significant portion of the Earth's crust and mantle due to the abundance of silicon and oxygen in the Earth's composition. Silicates are also the main components of rocks, such as granite and basalt, which are common in the Earth's crust and mantle.
28.
Mineral deposits which have been identified and can be extracted profitably are called __________
Correct Answer
A. reserves
Explanation
Mineral deposits that have been identified and are economically viable to extract are known as reserves. These reserves indicate the presence of valuable minerals that can be extracted and utilized for various purposes. This term is commonly used in the mining industry to refer to mineral deposits that have been proven to be economically feasible for extraction.
29.
All silicate minerals contain which two elements?
Correct Answer
D. silicon, oxygen
Explanation
Silicate minerals are composed primarily of silicon and oxygen. Silicon is the second most abundant element in the Earth's crust and is a key component of many minerals. Oxygen is the most abundant element in the Earth's crust and is also essential in the formation of silicate minerals. Therefore, all silicate minerals contain silicon and oxygen.
30.
Atoms that have an electrical charge due to a gain or loss of electrons are called __________.
Correct Answer
B. Ions
Explanation
Atoms that have an electrical charge due to a gain or loss of electrons are called ions. Ions are formed when an atom gains or loses electrons, resulting in an unequal number of protons and electrons. This imbalance in charge gives the atom a positive or negative charge, making it an ion. Isotopes are atoms of the same element that have different numbers of neutrons. Isochrons are lines on a graph that represent the same age. Periodic elements refer to the elements in the periodic table.
31.
Which of the following is correct for isotopes of the same element?
Correct Answer
B. The atoms have different numbers of neutrons and the same number of protons.
Explanation
Isotopes of the same element have the same number of protons, which determines the element's identity. However, they have different numbers of neutrons, resulting in different atomic masses. This is because isotopes are variants of an element that have the same number of protons but different numbers of neutrons. The different number of neutrons does not affect the electrical charge of the atom, as neutrons are electrically neutral. Therefore, the correct answer is that isotopes of the same element have different numbers of neutrons and the same number of protons.
32.
Granite and gabbro ________.
Correct Answer
A. Have a similar texture
Explanation
Granite and gabbro have a similar texture because they both have a coarse-grained appearance. This means that the individual mineral grains within the rocks are large enough to be seen with the naked eye. The texture of both granite and gabbro is a result of their formation from slowly cooling magma deep within the Earth's crust. Therefore, the correct answer is that granite and gabbro have a similar texture.
33.
Igneous rock is formed
Correct Answer
D. By crystallization of molten rock
Explanation
Igneous rock is formed by the crystallization of molten rock. When molten rock, or magma, cools and solidifies, it forms igneous rock. This process can occur either below the Earth's surface, resulting in intrusive igneous rock, or on the surface, resulting in extrusive igneous rock. The cooling and solidification of molten rock leads to the formation of interlocking crystals, giving igneous rocks their characteristic texture and composition.
34.
____________ was an ancient reptile that lived in South America and Africa during the late Paleozoic.
Correct Answer
D. Mesosaurus
Explanation
Mesosaurus is the correct answer because it was an ancient reptile that lived in both South America and Africa during the late Paleozoic era. Granopteris, Monastarious, and Glossopteris are not reptiles and do not match the description given in the question.
35.
Today, ____________ is in about the same geographic position as during late Paleozoic time.
Correct Answer
D. Antarctica
Explanation
During the late Paleozoic time, the continents were grouped together in a supercontinent called Pangaea. Antarctica was located near the South Pole, just like it is today. The other continents, including India, South America, and Australia, were positioned differently and not in the same geographic location as they are today. Therefore, the correct answer is Antarctica.
36.
Which of the following paleoclimatic evidence supports the idea of the late Paleozoic super continent in the Southern Hemisphere?
Correct Answer
B. Tillites (rocks formed by glaciers) in South Africa and South America
Explanation
The presence of tillites (rocks formed by glaciers) in South Africa and South America supports the idea of the late Paleozoic supercontinent in the Southern Hemisphere. Tillites are formed by the action of glaciers, indicating that these regions were once covered by ice sheets. The occurrence of tillites in both South Africa and South America suggests that these landmasses were once connected, supporting the concept of a supercontinent in the Southern Hemisphere during the late Paleozoic era.
37.
A very long-lived magma source located deep in the mantle is called a ____________.
Correct Answer
D. Hot spot
Explanation
A hot spot refers to a long-lived magma source located deep in the mantle. It is an area where magma rises to the surface, creating volcanic activity. This volcanic activity is not associated with plate boundaries, unlike other types of volcanoes. Hot spots are responsible for the formation of chains of volcanic islands, such as the Hawaiian Islands. They are believed to be caused by plumes of hot mantle material rising from deep within the Earth.
38.
Which of the following statements apply to the asthenosphere, but not the lithosphere?
Correct Answer
A. Zone in the upper mantle that deforms by plastic flowage
Explanation
The correct answer is "zone in the upper mantle that deforms by plastic flowage." This statement applies to the asthenosphere because it is a zone in the upper mantle where the rocks are hot and under high pressure, allowing them to flow and deform plastically. On the other hand, the lithosphere refers to the cool, rigid layer of crust and upper mantle that forms the tectonic plates. The lithosphere is not capable of plastic flowage and deformation like the asthenosphere.
39.
New oceanic crust and lithosphere are formed at ____________.
Correct Answer
C. Divergent boundaries by submarine eruptions and intrusions of basaltic magma
Explanation
New oceanic crust and lithosphere are formed at divergent boundaries by submarine eruptions and intrusions of basaltic magma. Divergent boundaries occur where tectonic plates are moving away from each other. As the plates separate, magma rises from the mantle and fills the gap, creating new crust. This magma is basaltic in composition, which is rich in iron and magnesium. The eruptions and intrusions of this basaltic magma at divergent boundaries lead to the formation of new oceanic crust and lithosphere.
40.
Cooler, older, oceanic lithosphere sink into the mantle at ____________.
Correct Answer
A. Subduction zones along convergent plate boundaries
Explanation
Cooler, older, oceanic lithosphere sinks into the mantle at subduction zones along convergent plate boundaries. This process occurs when two tectonic plates collide, and the denser oceanic plate is forced beneath the less dense continental plate. As the oceanic lithosphere sinks into the mantle, it can cause volcanic activity, earthquakes, and the formation of mountain ranges. This is a common geological process that contributes to the recycling of Earth's crust and the formation of new crust.
41.
A transform plate boundary is characterized by ____________.
Correct Answer
D. a deep, vertical fault along which two plates slide past one another in opposite directions
Explanation
A transform plate boundary is characterized by a deep, vertical fault along which two plates slide past one another in opposite directions. This type of boundary is also known as a conservative or strike-slip boundary. Unlike convergent boundaries where plates collide or divergent boundaries where plates move apart, transform boundaries involve horizontal movement. This movement can cause earthquakes as the plates slip and release built-up stress along the fault line. One well-known example of a transform plate boundary is the San Andreas Fault in California.
42.
The Aleutian Islands occur at a ____________
Correct Answer
A. Convergent boundary on a volcanic arc above a northward-subducting Pacific plate
Explanation
The Aleutian Islands occur at a convergent boundary on a volcanic arc above a northward-subducting Pacific plate. This means that the islands are located where two tectonic plates are colliding, with the Pacific plate being forced beneath the North American plate. This subduction process creates a volcanic arc, where magma rises to the surface and forms a chain of volcanic islands, such as the Aleutian Islands.
43.
____________ first related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid-ocean ridge.
Correct Answer
B. Vine and Matthews
Explanation
Vine and Matthews were the ones who first related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid-ocean ridge.
44.
What fundamental concept states that in a horizontal sequence of conformable sedimentary strata, each higher
bed is younger than the bed below it?
Correct Answer
A. Law of superposition
Explanation
The law of superposition states that in a horizontal sequence of conformable sedimentary strata, each higher bed is younger than the bed below it. This principle is based on the observation that as sediments are deposited, the older layers are typically buried beneath younger layers over time. By studying the order of sedimentary rock layers, geologists can determine the relative ages of the rocks and the events that occurred during their formation. This concept is fundamental in understanding the geological history of an area and the processes that have shaped the Earth's surface over time.
45.
Mount St. Helens is ________.
Correct Answer
B. An explosive stratovolcano
Explanation
Mount St. Helens is classified as an explosive stratovolcano due to its eruptive history and characteristics. Stratovolcanoes are tall, steep-sided volcanoes that are built up by layers of lava, ash, and other volcanic materials. Mount St. Helens fits this description as it has a conical shape and is composed of layers of hardened lava, ash, and pyroclastic materials. Additionally, Mount St. Helens is known for its explosive eruptions, such as the catastrophic eruption in 1980, which further supports its classification as an explosive stratovolcano.
46.
A ________ is an intrusive, igneous rock body that is tabular and concordant.
Correct Answer
B. Sill
Explanation
A sill is an intrusive, igneous rock body that is tabular and concordant. It is formed when magma is injected into horizontal cracks or layers of pre-existing rock and solidifies underground. Sills are parallel to the surrounding rock layers and do not cut across them. This makes them concordant. They are usually found in areas of volcanic activity and can have economic importance as a source of valuable minerals.
47.
Which one of the following stress situations results in folding of flat-lying, sedimentary strata?
Correct Answer
A. Horizontally directed; compressive stresses
Explanation
The folding of flat-lying, sedimentary strata occurs when compressive stresses are horizontally directed. This means that the forces pushing on the rock layers are coming from the sides, causing them to buckle and fold. Extensional stresses, whether horizontally or vertically directed, would cause the rock layers to stretch and potentially fracture, but not fold. Vertically directed compressional stresses would cause the rock layers to be squeezed from top to bottom, but not fold horizontally. Therefore, only horizontally directed compressive stresses can result in the folding of flat-lying, sedimentary strata.
48.
The concept that rocks of the crust and upper mantle are floating in gravitational balance is known as ________.
Correct Answer
C. Isostasy
Explanation
Isostasy is the concept that explains how rocks of the crust and upper mantle are floating in gravitational balance. It states that the Earth's crust is in equilibrium, with lighter materials floating on top of denser materials. This balance is maintained due to the principle of buoyancy, where the less dense rocks rise and the denser rocks sink. Isostasy plays a crucial role in shaping the Earth's surface and is responsible for phenomena such as mountain ranges and ocean basins.
49.
The ________ is the idea or concept that ancient life forms succeeded each other in a definite, evolutionary
pattern and that the contained assemblage of fossils can determine geologic ages of strata?
Correct Answer
A. Principle of fossil succession
Explanation
The principle of fossil succession is the idea or concept that ancient life forms succeeded each other in a definite, evolutionary pattern and that the contained assemblage of fossils can determine geologic ages of strata. This principle is based on the observation that different fossils appear in the rock layers in a specific order, with simpler organisms found in older layers and more complex organisms found in younger layers. By studying the fossils found in different layers of rock, scientists can determine the relative ages of the rocks and the organisms that lived during those times.
50.
Which one of the following shows the correct order (left to right) of decreasing magma viscosity?
Correct Answer
A. Rhyolite, andesite, basalt
Explanation
Rhyolite, andesite, and basalt are all types of volcanic rocks with varying magma viscosities. Viscosity refers to the resistance of a fluid to flow, and in the case of magma, it is influenced by factors such as temperature, silica content, and gas content. Rhyolite has the highest silica content and highest viscosity among the three, making it the most viscous. Andesite has a lower silica content and lower viscosity compared to rhyolite. Basalt has the lowest silica content and lowest viscosity among the three, making it the least viscous. Therefore, the correct order of decreasing magma viscosity is rhyolite, andesite, basalt.