Tectonic Tales: Earth And Geology Quiz

A volcano is indeed a hill or mountain that is formed by the accumulation of lava and other materials that have been erupted from the Earth's crust. Volcanoes are typically cone-shaped and can be found in various parts of the world. They are formed due to the movement of tectonic plates and the release of molten rock from beneath the Earth's surface. The erupted materials, such as lava, ash, and gases, build up over time and create the distinct shape of a volcano. Therefore, the statement "A volcano is a hill or mountain that is composed of lava and other erupted materials" is true.

A geologic cross section is a diagram that represents a vertical slice through the Earth's crust. It shows the different layers and features that would be visible if one could cut through the Earth's surface. This diagram helps geologists understand the structure and composition of the Earth's crust and the processes that have shaped it over time. Therefore, the statement "A geologic cross section is a diagram that shows features that would be visible if one could make a slice through the crust" is true.

Continental drift refers to the concept that the Earth's continents have moved and are still moving over time. This theory was proposed by Alfred Wegener in the early 20th century and is supported by various pieces of evidence, such as the matching shapes of coastlines on different continents and the distribution of fossils and rock formations. Therefore, the statement that continental drift is the large-scale movement of continents is true.

Hydrothermal activity refers to the movement of water through hot volcanic rocks and magmas. This process occurs when water seeps into the Earth's crust and is heated by the surrounding magma or rocks. The heated water then rises back to the surface, carrying with it dissolved minerals and gases. This activity is commonly associated with volcanic areas and can lead to the formation of hot springs, geysers, and mineral deposits. Therefore, the statement "Hydrothermal activity involves the circulation of water through hot volcanic rocks and magmas" is true.

Volcanically active areas can be good sources of heat energy for geothermal power because the intense heat generated by volcanic activity can be harnessed to produce steam, which in turn can be used to drive turbines and generate electricity. The heat from the volcanic activity is transferred to underground reservoirs of hot water or steam, known as geothermal reservoirs, which can be tapped into through wells. This makes volcanically active areas ideal locations for geothermal power plants, as they provide a constant and renewable source of heat energy.

Earthquakes can indeed cause tsunamis. When an earthquake occurs under the ocean floor, it can generate a series of powerful waves known as a tsunami. These waves can travel across the ocean and cause significant damage and destruction when they reach coastal areas. Therefore, the statement that earthquakes do not cause tsunamis is false.

C-C convergence refers to the collision of two continental plates, resulting in the formation of tall mountains. When two continental plates collide, they push against each other, causing the crust to buckle and fold, leading to the formation of mountain ranges. This process is responsible for the creation of some of the tallest mountains on Earth, such as the Himalayas and the Alps. Therefore, in the setting of C-C convergence, the tallest mountains are created.

Stratigraphy is the study of layers in sedimentary rock. It involves analyzing the different layers of rock to understand the geological history and sequence of events that have occurred over time. By examining the composition, thickness, and arrangement of these layers, stratigraphy helps geologists interpret past environments, climate changes, and the formation of fossils. Geochronology, on the other hand, focuses on determining the age of rocks and fossils, while paleontology studies the fossils themselves. Sedimentation refers to the process of deposition and accumulation of sediment.

Magnetic anomalies are indeed long, narrow, parallel bands that are almost symmetrical with the mid-ocean ridge. This is a characteristic feature of the oceanic crust, where new crust is continuously formed at the mid-ocean ridge and spreads out in both directions. As the new crust forms, it acquires the magnetic field of the Earth at that time. Over time, the Earth's magnetic field has reversed multiple times, resulting in a pattern of alternating magnetic polarities recorded in the oceanic crust. These alternating magnetic polarities create the long, narrow, parallel bands of magnetic anomalies observed on either side of the mid-ocean ridge.

Calderas are indeed larger features than craters. A caldera is a large volcanic crater formed by the collapse of a volcano's summit area. It is typically much larger in size compared to a crater, which is a smaller, bowl-shaped depression typically caused by the impact of a meteorite or the explosion of a volcanic vent. Therefore, the statement that calderas are larger features than craters is true.

Geologic maps are color maps that represent rock formations exposed at the Earth's surface. This means that they provide a visual representation of the different types of rocks and their distribution in a particular area. By using different colors and patterns, geologists can identify and classify the various rock formations, helping to understand the geological history and processes that have shaped the Earth's surface. Therefore, the statement "geologic maps are color maps that represent rock formations exposed at Earth's surface" is true.

The statement "all tectonic plates move across earth at the same rate" is false. Tectonic plates are large pieces of the Earth's lithosphere that move and interact with each other. They do not move at the same rate, but rather at different speeds and directions. This movement is driven by the process of plate tectonics, which involves the motion of the underlying mantle. The rate of plate movement can vary from a few centimeters to several centimeters per year, depending on the specific plate and location.

Pahoehoe is the name for a basaltic lava flow that has a ropy, folded surface. This type of lava flow is characterized by its smooth, undulating appearance, which is created as the lava cools and solidifies. The surface of pahoehoe lava flows often resemble twisted ropes or braids, giving it its distinctive appearance.

Pyroclasts are solidified fragments of volcanic material that are ejected into the air during a volcanic eruption. These fragments can range in size from tiny ash particles to larger rocks and can be made up of various materials such as lava, pumice, and volcanic glass. Pyroclasts are a common feature of explosive eruptions and can be found deposited around volcanic vents and on the surrounding landscape.

The explanation for the given correct answer is that a recurrence interval for earthquakes indeed refers to the time between earthquake ruptures. It is a measure used to estimate the average time period between earthquakes of a similar magnitude occurring in a specific area. By studying the recurrence interval, scientists can better understand the frequency and pattern of earthquakes, which is crucial for assessing seismic hazards and designing appropriate safety measures.

The statement is false because the smallest division of geologic time is not the era, but rather the epoch. The geologic time scale is divided into eons, which are further divided into eras. Each era is then divided into periods, and each period is divided into epochs. Therefore, the era is not the smallest division of geologic time.

Mass extinctions have played a significant role in shaping the geologic time scale. These events, characterized by the rapid and widespread loss of species, have led to major shifts in the composition and diversity of life on Earth. The boundaries between different time periods in the geologic time scale often coincide with these mass extinctions, as they represent significant turning points in the history of life on our planet. Therefore, it is true that many boundaries of the geologic time scale are marked by mass extinctions.

A basin is a geological structure that is characterized by strata that dip towards a central point. This means that the layers of rock or sediment within the basin slope downwards towards the center of the basin. This is typically caused by the process of sedimentation over time, where material accumulates in a central area, creating a depression or low-lying region. Therefore, the statement that a basin is a synclinal structure with strata that dip toward a central point is true.

Brittle materials deform by faulting, whereas ductile materials deform by folding. This statement best describes the behavior of rocks during deformation. Brittle materials, such as certain types of rocks, tend to fracture and form faults when subjected to stress. On the other hand, ductile materials, like some types of rocks, can undergo plastic deformation and fold under stress. This distinction in deformation behavior between brittle and ductile materials is important in understanding the geological processes and structures that occur in the Earth's crust.

Carbon-14 is the most useful radioactive isotope for dating very young wood and charcoal because it has a half-life of about 5730 years, which is suitable for dating materials up to 10,000 years old. Carbon-14 is constantly being produced in the atmosphere and taken in by living organisms, so it can be used to determine the age of organic materials. The other isotopes listed have much longer half-lives and are more suitable for dating much older materials.

Seismic waves are generated by earthquakes and travel through the Earth's layers. The first type of wave to arrive at a seismograph station is the P wave, also known as the primary wave. P waves are compressional waves that travel through solids, liquids, and gases. The next type of wave to arrive is the S wave, also known as the secondary wave. S waves are shear waves that only travel through solids. Finally, the last type of wave to arrive is the surface wave. Surface waves are slower than P and S waves and they move along the Earth's surface, causing the most damage. Therefore, the correct order in which seismic waves arrive at a seismograph station is P waves → S waves → surface waves.

The Phanerozoic eon is the correct answer because it is the eon during which humans evolved. The Phanerozoic eon spans from about 541 million years ago to the present day and is characterized by the diversification and proliferation of complex life forms, including humans. The Archean, Hadean, and Proterozoic eons precede the Phanerozoic eon and do not encompass the time period in which humans evolved.

The smallest division of geologic time is an epoch. Geologic time is divided into larger units called eons, which are further divided into eras, then periods, and finally epochs. An epoch represents a relatively short period of time, usually characterized by distinct changes in the Earth's environment or the appearance or extinction of specific species. Therefore, an epoch is the smallest division of geologic time.

The explanation for the given correct answer, which is False, is that a mass extinction is not a short period in time but rather a prolonged event that leads to the extinction of a significant number of species. It is not limited to a small percentage of species dying, but rather involves a substantial loss of biodiversity on a global scale.

Earthquakes at transform plates are not evidence for continental drift. While earthquakes do occur at transform plate boundaries, they are a result of the movement of tectonic plates along these boundaries, rather than evidence for the concept of continental drift. Continental drift is supported by evidence such as fossil distribution, rock assemblage distribution, and the jig saw puzzle fit of continents, which provide geological and biological evidence for the movement of continents over time.

Volcanism does not occur in continent-continent collision zones because these zones involve the convergence of two continental plates, which are composed of less dense rock compared to oceanic plates. As a result, the collision causes the two plates to buckle and fold, creating mountain ranges rather than volcanic activity. Volcanism is more common in hot spots, mid-ocean ridges, and subduction zones where the movement of tectonic plates allows for the formation of magma and volcanic eruptions.

Fumaroles are small vents on volcanoes that emit gas fumes and steam. They are formed when water seeps into the ground and comes into contact with hot rocks or magma, causing it to rapidly turn into steam. The steam and gas are then released through the fumaroles. These vents can often be seen as small openings emitting white or gray smoke, and they are a common feature of volcanic activity.

The statement "craters are larger than calderas" is false. Calderas are actually larger than craters. A crater is a bowl-shaped depression formed by the impact of a meteorite or volcanic activity, while a caldera is a large volcanic crater that is formed when a volcano collapses after a massive eruption. Calderas can be several kilometers in diameter, much larger than most craters.

The principle of original horizontality states that sediments are deposited as horizontal layers. This means that when new sediment is deposited, it tends to settle in a flat, horizontal position. Over time, these layers can become compacted and lithified to form sedimentary rocks. This principle is important in understanding the relative ages of rock layers and the processes that shape the Earth's surface.

The elastic rebound theory describes the process of stress building up in the Earth's crust during an earthquake and then being released in the form of seismic waves. This theory explains how the Earth's crust can store and release energy, causing the ground to shake during an earthquake. It helps us understand the mechanics of earthquakes and how they occur.

A lahar is a torrential flow of wet volcanic debris. This can occur when volcanic material, such as ash and rock fragments, mixes with water, either from melting snow and ice or heavy rainfall. The resulting mixture becomes a fast-moving mudflow that can travel down the slopes of a volcano, often following existing river valleys. Lahars can be extremely destructive, as they can carry large boulders and debris, causing significant damage to infrastructure and posing a threat to human settlements downstream.

The statement is true because eons are the largest divisions of geologic time and each eon represents a significant amount of time. They are divided into smaller units such as eras, periods, and epochs, which represent shorter periods of time. Therefore, it can be concluded that all eons encompass different amounts of geologic time.

The correct answer is that the dike is younger than the sandstone. This is because a dike is an intrusive igneous rock that cuts across existing rock layers, indicating that it formed after the sandstone. The sandstone, on the other hand, is a sedimentary rock that formed from the accumulation of sediment over time. Therefore, the dike must be younger than the sandstone.

Rift valleys form in a setting of C-C divergence. This is because C-C divergence occurs when two continental plates move away from each other. As the plates separate, tensional forces cause the lithosphere to stretch and thin, resulting in the formation of a rift valley. This process is commonly observed in regions such as the East African Rift System, where the African Plate is splitting apart.

The dip of a unit represents the angle at which the bed inclines from the horizontal. This angle indicates the slope or inclination of the rock layer, providing information about its orientation and how it deviates from a horizontal position.

Continental rifts are formed at divergent plate boundaries. In this setting, the Earth's lithospheric plates move away from each other, creating a gap. As the plates separate, magma rises from the asthenosphere and fills the gap, leading to the formation of a new crust. Over time, this process can result in the splitting and separation of continents, forming a continental rift. This is evident in the East African Rift System, where the African Plate is slowly splitting apart.

Pillow basalt is the correct answer because it is a type of basaltic lava that forms underwater. When lava erupts into water, it cools rapidly and forms rounded, pillow-like structures. This process occurs in submarine volcanic eruptions or when lava flows into bodies of water such as oceans or lakes. The other options mentioned in the question, such as pyroclasts, pahoehoe, and volcanic breccia, can form both underwater and on land during volcanic eruptions.

At divergent plate boundaries, the plates move away from each other, creating a gap. As the plates separate, magma rises from the mantle and fills the gap, forming new crust. This process is known as seafloor spreading. The creation of new crust at divergent boundaries actually leads to an increase in plate area, rather than a decrease. Therefore, the given statement is false.

An unconformity refers to a gap in the geologic record, where there is a discontinuity in the layers of rocks or sedimentary deposits. This gap can occur due to erosion, tectonic activity, or non-deposition of sediment over a period of time. Unconformities are significant in studying the Earth's history as they represent missing periods of time and can provide insights into past geological events and changes in the environment.

Earthquakes occur when there is a sudden release of energy in the Earth's crust, causing seismic waves. This release of energy happens when rocks that are under stress reach their breaking point and fail, causing the ground to shake. Therefore, the statement "Earthquakes occur when rocks under stress suddenly fail" is true.

Phenocrysts are not solidified fragments of volcanic material that are ejected into the air. They are actually large crystals that form in the magma chamber beneath a volcano before an eruption. These crystals can be carried to the surface during an eruption, but they are not fragments that are ejected into the air. Therefore, the correct answer is false.

Basalt found on the seafloor is the correct answer because scientists study magnetic anomalies using a method called paleomagnetism. Basalt contains magnetic minerals that align with the Earth's magnetic field as it solidifies. By studying the orientation of these magnetic minerals in basalt samples, scientists can determine the past positions of the Earth's magnetic poles and track the movement of tectonic plates over time. Since basalt is commonly found on the seafloor, it provides a valuable source of information for studying magnetic anomalies and plate tectonics.

Shearing forces are the correct answer because they cause two sides of a body to slide horizontally past one another. These forces occur when two plates in the Earth's crust move in opposite directions, causing friction and creating faults or fractures in the rocks. This movement can result in earthquakes and the formation of features such as transform boundaries.

Mid-ocean ridges are underwater mountain ranges where new oceanic crust is formed through volcanic activity. These ridges are characterized by the spreading of tectonic plates, which creates a gap or a rift in the ocean floor. This process is known as seafloor spreading. Therefore, the term "spreading centers" is an accurate description of mid-ocean ridges.

Radioactive decay is a spontaneous process that occurs at a constant rate and is not influenced by external factors such as temperature, chemical reactions, or pressure. The rate of radioactive decay is determined solely by the inherent properties of the radioactive material itself and is not affected by any external conditions. Therefore, nothing can change the rate of radioactive decay.

The correct order is eon, era, period, epoch. This is because an eon is the largest division of geologic time, followed by an era, which is a subdivision of an eon. A period is a subdivision of an era, and finally, an epoch is the smallest division of geologic time, occurring within a period.

The half-life of a radioactive element is the time it takes for half of the atoms of the parent element to decay into the daughter element. In this case, the rock started with 1000 atoms of the radioactive parent element and now contains only 250 radioactive parent atoms. This means that half of the original parent atoms have decayed. Since the half-life of the radioactive element is one million years, it would take two million years for half of the parent atoms to decay. Therefore, the rock is 2 million years old.

S waves are a type of seismic waves that move in a shearing motion, causing particles to move perpendicular to the direction of wave propagation. This type of motion is characteristic of shear waves, which is why S waves are classified as shear waves. Compressional waves, on the other hand, cause particles to move parallel to the direction of wave propagation, while surface waves are a combination of both longitudinal and transverse motions. Tsunamis, on the other hand, are not seismic waves but rather ocean waves caused by underwater disturbances.

To locate the epicenter of an earthquake, at least three seismograph stations are needed. Each seismograph station records the arrival time of the earthquake's seismic waves. By comparing the arrival times from multiple stations, the distance between each station and the epicenter can be determined. The intersection of these distances allows for the precise location of the epicenter. Therefore, three seismograph stations are the minimum requirement for accurately locating the epicenter of an earthquake.

A stratovolcano is a type of volcano that has alternating layers of lava and pyroclastic materials. These volcanoes are characterized by their steep sides and cone-shaped appearance. The alternating layers are formed as a result of repeated eruptions, where lava flows and pyroclastic materials such as ash, rocks, and gases are ejected from the volcano. Over time, these layers build up and create the distinct structure of a stratovolcano. This type of volcano is known for its explosive eruptions and can be found in various locations around the world.