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148 Cards in this Set
- Front
- Back
Which ocean is the deepest on Earth?
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Pacific Ocean
This ocean is also the largest ocean in the world and contains the deepest spot, the Mariana Trench at 11,022 meters (36,161 feet) below sea level. |
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True or False? All of the continents could fit into the space occupied by the Pacific Ocean.
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True
The area of the continents would easily fit within the present area of the Pacific Ocean. (Please see page 7 of your textbook.) |
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True or False? The deepest spot in the ocean is deeper than Mount Everest is high.
|
True
The Mariana Trench is 2172 meters (7126 feet--about a mile and a half) deeper than Mount Everest is high. (Please see page 10 and Figure 1-4 in the text.) |
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The Age of Discovery is the time period in ocean exploration history when
|
the Western European world realized the vastness of Earth's water-covered surface.
The Age of Discovery is the period of 1492 to 1522, during which time the voyages of Columbus and Magellan were undertaken. |
|
Based on the scientific method, science supports the explanation of the natural world that
|
best explains all available obervations.
The most widely accepted scientific explanation is the one that explains ALL available observations. Because new observations can modify existing ideas, science is always developing. |
|
Which of the following is NOT true concerning density stratification?
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This has caused our Earth to be homogeneous throughout.
Of the 5 possible choices, this is the only one that is NOT true about density stratification. |
|
Which of the following represents the oldest time unit?
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Precambrian
The Precambrian Period ranges from the origin of Earth at about 4.6 billion years ago to about 570 million years ago. |
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The oceans are believed to have formed about
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4 billion years ago.
The oceans are thought to have formed about 4 billion years ago after most of Earth's water condensed. |
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The GPS system is a tool used for determining ocean __________________.
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location
Earth-orbiting satellites transmit signals to Earth that can be picked up by GPS receivers, enabling a precise determination of latitude, longitude, and even surface elevation. |
|
The cosmological model for the formation of the sun and the rest of our solar system is called the ___________________.
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Nebular Hypothesis
This hypothesis suggests that a nebular cloud of rotating gas and space dust concentrated particles under the force of gravity into the sun, and material left behind in small eddies became protoplanets. |
|
The subdivisions of the geologic time scale
|
were initially based on fossil evidence, extinctions, and boundaries of sedimentary rock units.
Before modern techniques of radiometric age dating, early geologists created the geologic time scale based on available evidence such as major extinctions. |
|
The most accurate scientific estimation of the age of Earth is based on
|
radiometric methods of detemining the age of meteorites and moon rocks.
These are the fragments of the early solar system that give us a reliable age of Earth. |
|
Approximately what percentage of the surface of Earth is covered by oceans?
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71%
A total of 70.8 percent (almost 71 percent ) is covered by oceans. |
|
Stanley Miller's 1952 experiment demonstrated that
|
organic molecules could be created from the materials contained in Earth's early atmosphere and ocean.
Stanley Miller's now-famous 1952 experiment demonstrated that organic molecules could be created from the materials contained in Earth's early atmosphere and ocean, suggesting that life on Earth began in the oceans. |
|
The first known circumnavigation of Earth was by the vessel, Victoria, the voyage of which was led by whom?
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Ferdinand Magellan
Ferdinand Magellan led the first known circumnavigation of Earth. |
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The largest ocean in the world is the _______ Ocean.
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Pacific
The Pacific Ocean is the largest ocean in the world--as well as the single largest geographic feature of our planet. HINT This ocean is located between North America and Australia. |
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The group of Europeans known as the _______ were the first Europeans known to have traveled to North America.
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Vikings
The Vikings were the first Europeans known to have traveled to North America. HINT These Europeans hailed from Scandinavia and sailed to Iceland, Greenland, and west to North America. |
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The chronometer developed by John Harrison was valuable because it made possible the determination of _______ at sea.
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longitude
The marine chronometer allowed accurate time to be kept at sea, a necessity for accurately determining longitude. HINT This timepiece was first used by Captain James Cook, who needed it to calculate this and supplement his ship's determination of latitude. |
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The early oceans and atmosphere are thought to have come from inside Earth and were formed by a process called _______.
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outgassing
This process of the movement of gases from inside Earth to outside is called outgassing. HINT This process is the movement of gases from inside Earth to outside. |
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The early Earth that was much larger than the present day earth was called the _______.
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Protoearth
The large, early Earth was called the Protoearth. HINT This answer includes the word "proto-", meaning early (one word). |
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Earth is a layered sphere based on the property of _______.
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density
Earth is a layered sphere based on density, where the most dense material is near the core and density decreases toward the surface. HINT This property can be thought of as how heavy something is for its size. |
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The free oxygen in our present atmosphere is thought to have been produced through the process of _______.
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photosynthesis
Photosyntesis, which releases oxygen gas, is the process by which free oxygen was added to the atmosphere. HINT Chemically, this is the opposite of respiration. |
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During photosynthesis or respiration, an _______ reaction is a chemical reaction that releases heat energy.
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exothermic
An exothermic reaction occurs during respiration to release heat energy (hence the "exo-" part of the word). HINT The answer includes the term "thermic." |
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The most widely accepted age of Earth is _______ billion years.
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4.6
Based on the radioactive decay of moon rocks and meteorites, Earth is approximately 4.6 billion years old. HINT Be exact--the answer includes a decimal point! |
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When diving, rapid ascent from great depth can cause the _______, a painful illness that may cause death.
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bends
The bends is caused by bubbles from dissolved gasses blocking blood flow. HINT It is caused when bubbles block blood flow in the veins. |
|
Approximately what percentage of the surface of Earth is covered by oceans?
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71%
A total of 70.8 percent (almost 71 percent ) is covered by oceans. |
|
Which ocean is the deepest on Earth?
|
Pacific Ocean
The Pacific Ocean is the largest and deepest ocean in the world. It also contains the world's deepest spot, the Mariana Trench, at 11,022 meters (36,161 feet) below sea level. |
|
True or False? The deepest spot in the ocean is deeper than Mount Everest is high.
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True
The Mariana Trench is 2172 meters (7126 feet, which is about a mile and a half) deeper than Mount Everest is high. See Figure 1.3. |
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True or False? All of the continents could fit into the space occupied by the Pacific Ocean.
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True
The area of the continents (29% of Earth's surface) would easily fit within the area of the Pacific Ocean (about 33% of Earth's surface). See also Figure 1.5. |
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Based on the scientific method, science supports the explanation of the natural world that
|
best explains all available observations.
The most widely accepted scientific explanation is the one that explains ALL available observations. Because new observations can modify existing ideas, science is always developing. |
|
The Age of Discovery is the time period in ocean exploration history when
|
the Western European world realized the vastness of Earth’s water-covered surface.
The Age of Discovery is the period of 1492 to 1522, during which time the voyages of Columbus and Magellan were undertaken. Magellan's voyage was the first to circumnavigate the globe. |
|
The first known circumnavigation of Earth was by the vessel Victoria, the voyage of which was led by whom?
|
Ferdinand Magellan
Although Del Caño was Magellan's servant and led the one remaining ship back to Spain after Magellan was killed in the Philippines, he was not the leader of the expedition. |
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The GPS system is a tool used for determining __________________ within the ocean.
|
location
Earth-orbiting satellites transmit signals to Earth that can be picked up by GPS receivers, enabling a precise determination at sea of latitude, longitude, and even surface elevation. |
|
The most accurate scientific estimation of the age of Earth is based on
|
radiometric methods of determining the age of meteorites and moon rocks.
These are the fragments of the early solar system that give us a reliable age of Earth. |
|
The cosmological model for the formation of the Sun and the rest of our solar system is called the ___________________.
|
Nebular Hypothesis
This hypothesis suggests that a nebular cloud of rotating gas and space dust concentrated particles under the force of gravity into the sun, and material left behind in small eddies became protoplanets. |
|
The oceans are believed to have formed about
|
4 billion years ago.
The oceans are thought to have formed about 4 billion years ago, after most of Earth's water condensed. |
|
True or False? The early oceans and atmosphere are thought to have come from inside Earth, and were formed by a process called outgassing.
|
True
Both Earth's oceans and atmosphere are thought to have come from inside Earth through outgassing. |
|
Which of the following is NOT true concerning density stratification?
|
This has caused our Earth to be homogeneous throughout.
Of the 5 possible choices, this is the only one that is NOT true about density stratification. |
|
Of the following, which best describes the physical property of the asthenosphere?
|
plastic
The asthenosphere is composed of hot rock material that has high viscosity plastic properties (has the ability to flow slowly over time). |
|
What physical property of Earth’s layers determines the order in which they are layered?
|
density
The density of Earth’s layers determines the order in which they are layered, with lower density material above those of higher density. |
|
The vertical movement of crust to accommodate additional weight or removal of weight is called
|
isostatic adjustment
The vertical movement of crust is called isostatic adjustment. See Figure 1.16 |
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Which of the following gases was absent from Earth's early atmosphere?
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oxygen
Plant life got rid of this gas as a waste product of photosynthesis. |
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The naturalist Charles Darwin, who is credited with developing the theory of evolution by natural selection, suggested that adaptations of organisms were the result of
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adaptations to different environmental conditions.
According to the theory of evolution, an organism's adaptations are shaped by its environment and its mode of existence. |
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Stanley Miller's 1952 experiment demonstrated that
|
organic molecules could be created from the materials contained in Earth's early atmosphere and ocean.
Stanley Miller's now-famous 1952 experiment demonstrated that organic molecules could be created from the materials contained in Earth's early atmosphere and ocean, suggesting that life on Earth began in the oceans. |
|
The subdivisions of the geologic time scale
|
were initially based on fossil evidence, extinctions, and boundaries of sedimentary rock units.
Before modern techniques of radiometric age dating, early geologists created the geologic time scale based on available evidence such as major extinctions. |
|
Of the following events, which occurred during the Age of Discovery in Europe?
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Ferdinand Magellan's crew completed the first circumnavigation of the globe.
Christopher Columbus made several trips across the Atlantic and discovered a "new world." Magellan's crew completed their voyage in 1522, which marked the end of the Age of Discovery in Europe. Columbus made his first voyage in 1492, which marked the beginning of the Age of Discovery in Europe. |
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In science, which one of the following would be considered an observation?
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Waves are seen to approach the beach at an angle.
This is an observation (something that can be seen with the eye), which also can be considered a "fact." |
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Which of the following would best describe the principle goal of science?
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to explain the causes and effects of observable natural phenomena.
Science uses observations to explain cause and effect in the physical world and make successful predictions. |
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Of the following statements related to the formation of a density-stratified Earth, which is/are true?
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Earth is layered based on density, with the highest density material located at the deepest depths beneath Earth's surface.
Molten material will rise if it is less dense than the surrounding material. Molten material will sink if it is more dense than the surrounding material. More dense material sinks; less dense material rises. |
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Of the following statements about the internal structure of Earth, which is/are true?
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Earth's internal layers can be described by their composition or by their physical properties.
The lithosphere of Earth is made of both mantle and crust. There are 2 independent ways to describe the internal layers of Earth. The lithosphere contains all of the crust (either oceanic or continental) and the topmost part of the mantle. |
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Of the following statements about the asthenosphere, which is/are true?
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The asthenosphere is a plastic layer that extends from the base of the lithosphere to a depth of about 700 kilometers.
The asthenosphere is very hot and contains areas of partially molten rock. Asthenospheric mantle is hot, mobile, and partially molten. |
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Of the following statements about Earth's crust, which is/are true?
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Continental crust is less dense than oceanic crust.
Continental crust is made of rock that is relatively light in color. As compared to oceanic crust, continental crust is less dense, thick, and composed of light-colored granite. |
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Of the following statements about density stratification, which is/are true?
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Outgassing is a direct result of density stratification.
Density stratification has caused Earth's internal structure to be layered. Density stratification has caused the highest density material to be found at Earth's core. The origin of Earth's oceans and atmosphere are a result of density stratification. |
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Based on the concept of isostasy, which of the following would result in the uplift of Earth's surface?
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Lithosphere that was heated up by hot asthenosphere.
Lithosphere that was made to be less dense. Lithosphere that was thickened by mountain building. Thick lithosphere, less dense lithosphere, and hot lithosphere will rise higher. This will result in the depression of Earth's surface. |
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Which of the following idea(s) about the development of life on Earth make scientific sense?
|
As life developed on Earth, it began to significantly change Earth's environment.
Early organisms likely evolved into more complex organisms. Primitive life likely existed without the need for oxygen. The "prebiotic soup" of the primitive oceans provided a likely environment for life to develop. Not all primitive life needed sunlight; in fact, photosynthesis didn't evolve until later. Earths' environment has been substantially altered by life on Earth. |
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What physical property of Earth's layers determines the order in which they are layered?
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density
Think of why oil lies on top of water. |
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How is it that the floor of the ocean is so much younger than the ocean itself?
|
It is because the ocean floor keeps regenerating itself
Think about what creates new ocean floor. |
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Paleomagnetism is a key piece of evidence that helps support plate tectonics because it can be used to show
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the spreading of the sea floor.
Paleomagnetism--particlulary as applied to the ocean floor--provided a key piece of evidence to help support plate tectonics. |
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Given that continental crust is thicker than oceanic crust, why doesn't isostatic adjustment cause the continents to sink below the ocean?
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Continental crust is less dense than oceanic crust.
Even though the continental crust is thicker, it is lower in density than oceanic crust. Thus, it will "ride higher" than oceanic crust. Think about the physical property that allows objects to float on water. |
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The faster the spreading rate, the ________ the mountain range associated with spreading.
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broader
Deepening of the ocean floor correlates directly with the amount of time the lithosphere has cooled. |
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A volcanic arc forms near where there is
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subduction
A volcanic arc forms near where oceanic crust is being forced down into the mantle. |
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Alfred Wegener used all of the following lines of evidence in support of drifting continents, EXCEPT
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the composition of meteors from outer space.
|
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As one moves away from the axis of a mid-ocean ridge, the
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lithosphere thickens.
Lithospheric plates thicken with increasing distance from the mid-ocean ridge. |
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True or False? The mid-ocean ridge is the location of the oldest ocean floor.
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False
Think about from where the new ocean floor comes and to where it spreads. |
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Your job is to locate the world's plate boundaries. To do this, you can use only one map. The best map to choose for this job is a map that shows the worldwide locations of ___________________.
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earthquakes
Since the majority of tectonic activity (such as earthquakes) occurs along all types of plate boundaries, a map of worldwide earthquakes will be a good represention of plate boundaries. |
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Plate boundaries where new lithosphere is being added along a mid-oceanic ridge are called
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divergent boundaries.
Think of how the plates must be traveling in relation to each other for material to come up between them. |
|
When an oceanic and a continental plate converge,
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the oceanic plate will be subducted.
Consider the density of each plate. |
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When two continental plates converge,
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neither subducts; instead, a mountain range forms.
The densities of continental plates are generally the same. |
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True or False? Most lithospheric plates contain both oceanic and continental crust.
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True
Yes, most plates do contain both oceanic and continental crust because plate boundaries do not always follow the edges of the continents. |
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Overall, the Atlantic Ocean basin is ________ and the Pacific Ocean basin is ________.
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growing; shrinking
Remember, the mid-ocean ridge is the source of new crust that forms ocean basins. |
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Molecular structure controls _______, a measure of the tendency of a substance to resist flow.
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viscosity
Viscosity is a measure of the tendency of a substance to resist flow. For instance, the asthenosphere has high viscosity and does not flow easily. HINT This word comes from "viscous." |
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Alfred Wegener conceived of a single ancient landmass called _______ that began to break apart about 180 million years ago.
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Pangaea
Wegener called this supercontinent Pangaea, "all Earth." HINT Literally, this landmass was "all Earth." Be sure to check the spelling carefully! |
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Dating of ocean floor samples by the Deep Sea Drilling Project showed that ocean crust gets progressively _______ with increasing distance from the mid-ocean ridge.
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older
Ocean crust gets progressively older with increasing distance from the mid-ocean ridge. HINT Where is ocean crust formed? |
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The vertical movement of crust to accommodate additional weight or removal of weight is called _______.
|
isostatic adjustment
Isostatic adjustment is the vertical movement of crust. HINT The answer has two words and is analogous to buoyancy. |
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The region of Earth that is rigid, mobile, and contains the continents is called the _______.
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lithosphere
The lithosphere is the cool, rigid shell that is broken up into Earth's tectonic plates. HINT It is the outermost portion of Earth based on physical properties (not chemical composition). |
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A mantle plume can rise from deep within the mantle to create a _______ at the surface.
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hotspot
Hotspots are created when heat from deep within the mantle is released by plumes of hot material creating an abundance of volcanic activity at the surface. HINT The reason this spot is so hot is because of all the volcanic activity (one word). |
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A circular coral reef that has a well-developed lagoon and no visible central volcanic island would be in the _______ stage of coral reef formation.
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atoll
A coral atoll is created when the central volcanic island has sunk beneath the surface, leaving a circular coral reef with a well-developed lagoon in the middle. HINT At this stage, the central volcanic island has sunk beneath the surface and can't be seen "at all" (one word). |
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The area between two offset segments of a mid-ocean ridge is an example of a _______ plate boundary.
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transform
Transform boundaries occur between offset segments of a mid-ocean ridge. HINT The San Andreas fault is also an example of one of these types of plate boundaries. |
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When the leading edge of two converging plates is composed of oceanic crust, an _______ arc system will form.
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island
Island arc systems form where subduction occurs. HINT Japan is one of these. |
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The Andes Mountains have formed as a result of oceanic crust converging with _______ crust.
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continental
The Andes Mountains are a continental arc trench system, formed as the oceanic Nazca plate is subducted beneath the continental South American plate. HINT The Andes are located along the west coast of South America and have an ocean trench (the Peru-Chile Trench) offshore. |
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A surface feature called a _______ is thought to be the cause of the formation of the Hawaiian Islands.
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hotspot
The Hawaiian Islands are created by a hotspot, which is a relatively stationary place within the interior of a plate that has anomalously high heat flow and molten magma close to the surface. See Figure 2-28. HINT There is an abundance of volcanic activity here (one word). |
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A tall volcanic peak that forms on the ocean floor and is flat on top is called a _______ or guyot.
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tablemount
Tablemounts are tall volcanic peaks that have been planed off flat on top by wave action, then later are carried by plate motion to deeper depths. See Figure 2-29. HINT These volcanic peaks have been planed off flat on top by wave action, then later are carried by plate motion to deeper depths. |
|
A _______ plate boundary is created where two plates come together.
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convergent
A convergent plate boundary is created where two plates come together. HINT This is occurring at places like the Aleutian Islands and northern India. |
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A _______ plate boundary is created where two plates move apart.
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divergent
A divergent plate boundary is created where two plates move apart. HINT This is occurring in places like Iceland and east Africa. |
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A _______ plate boundary is created where two plates slowly grind past one another.
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transform
A transform plate boundary is created where two plates slowly grind past one another. HINT This is occurring in places like the San Andreas Fault in California, between segments of the mid-ocean ridge, and along the Alpine Fault in New Zealand. |
|
![]()
On the tectonic plate map shown below, correctly identify the names of the plates with the corresponding letters.
|
![]()
A-South American Plate
B-Pacific Plate C-Nazca Plate D-North American Plate E-African Plate F-Eurasian Plate |
|
All of the following features are associated with the mid-ocean ridge axis, EXCEPT
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trenches
Mid-ocean ridges are entirely volcanic and represent divergent plate boundaries. |
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The steep transition zone between the outer edge of the continental shelf and the deep-ocean basin is called the ____________________.
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continental slope
This is where continental plate meets oceanic plate on active margins. |
|
If you were to walk out away from shore across a passive continental margin, what is the order of provinces you would cross?
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continental shelf, slope, then the rise
Remember that a passive margin has no plate boundary. |
|
Which of the following is NOT true concerning a graded bedding deposit?
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It results from sucessive lava flows.
Graded bedding is a type of layering of material that is deposited as a result of a turbidity current. |
|
The Ring of Fire is located
|
around the margins of the Pacific Ocean
Where are the majority of the world's deep-ocean trenches and associated volcanoes located? |
|
True or False? Turbidity currents are highly erosive and are thought to be responsible for the creation of deep-sea trenches.
|
False
With which type of plate boundary are deep-sea trenches associated? |
|
True or False? The Aleutian Islands are associated with an active continental margin.
|
True
The Aleutian Islands are a volcanic island arc in Alaska and are associated with a trench. |
|
Which of the following is NOT true of submarine canyons?
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They are found only off mountainous coasts.
Visualize a canyon emerging out of the sides of a high plateau. |
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A small, rounded, submerged volcanic hill that rises less than 1 kilometer (0.6 mile) above the sea floor is called a/an
|
abyssal hill
These are also known as seaknolls. |
|
The reason that the mid-ocean ridge has a zigzag appearance is because
|
it accomodates spreading of a linear ridge system on a spherical Earth.
Remember that Earth's plates ride on a sphere! |
|
True or False? Pillow lavas (pillow basalts) indicate that molten lava came in contact with water and cooled very quickly.
|
True
Why are they called pillows? |
|
Bathymetry involves the measurement of the
|
depth of the ocean floor below sea level.
Bathmetry is a tool to map the relief of the sea floor. |
|
Ocean depths are routinely determined by
|
sending sound through the water and determining the time required for it to return to the ship.
Dolphins have been using a technique similar to this for millions of years to determine distances in the ocean where they cannot see. |
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The continental margin of the U.S. Atlantic coast is a/an ____________ continental margin, and the continental margin off the west coast of South America is a/an _____________ continental margin.
|
passive; convergent-active
Think about what kinds of plate boundaries (if any) are associated with these two areas. |
|
All of the following are true about fracture zones, EXCEPT
|
they are transform plate boundaries.
An example of a fracture zone is the Mendicino Fracture Zone, which is offshore past the end of the San Andreas Fault and oriented nearly perpendicular to the California coast. |
|
The four principle oceans of the Earth are the:
|
Atlantic, Arctic, Indian, and Pacific Oceans.
|
|
All of the following are TRUE concerning the deepest part of the ocean except:
|
The depth of the trench is estimated at 17,500 m.
|
|
The separation of the Earth into layers was the result of the:
|
differing densities of the rock and mineral materials.
|
|
Oceanic crust is primarily:
|
basalt.
|
|
Which of the following statements regarding continental and oceanic crust is TRUE?
|
Continental crust is thicker and less dense than oceanic crust.
|
|
The relatively flat areas that adjoin most continents are called continental _______.
|
shelves
Continental shelves are the relatively flat areas that adjoin most continents. HINT The answer rhymes with what Santa's helpers are called (plural). |
|
A commonly used type of survey for determining bathymetry is called side-scan _______.
|
sonar
Side-scan sonar uses transmitters directed away from both sides of the ship to map strips of ocean floor up to 60 km wide. HINT Bats use this to "see." |
|
The boundary between the continent and ocean is called the continental _______.
|
margin
The continental margin is composed of rift blocks of continental crust that gradually become covered by thick masses of sediment. HINT This is also an area on a piece of notebook paper. |
|
The east coast of North America is an example of a _______ continental margin.
|
passive
The east coast of North America is considered to be a passive margin because there is little associated seismic activity. This is in contrast with an active margin, such as the west coast of North America. HINT It's the opposite of active. |
|
Submarine canyons are cut by _______ currents.
|
turbidity
Turbidity currents, flows of sediment-laden water, periodically move down the continental slope and cut deep canyons. HINT These are underwater avalanches that lift and suspended sediment. |
|
_______ lavas indicate that molten lava came in contact with water and cooled very quickly.
|
Pillow
The smooth, rounded texture of pillow lavas suggests that there was sudden chilling of lava by contact with cold seawater. HINT The texture of these lavas is said to resemble an item that you use to lay your head on when sleeping. |
|
Fracture zones are the extensions of _______ faults beyond the areas of mid-ocean ridge offset.
|
transform
Fracture zones are the extensions of transform faults that exist beyond the offset segments of the mid-ocean ridge. HINT The San Andreas is an example of this type of fault on land (but the word is not "strike-slip"). |
|
The deepest parts of the sea floor occur in deep ocean _______.
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trenches
Ocean trenches, created by plate convergence, are the deepest parts of the sea floor. HINT Rhymes with "benches" (plural). |
|
Seamounts with flattened tops are called _______ or guyots.
|
tablemounts
Tablemounts have flattened tops that were created by wave activity at the ocean surface. HINT Think about where you normally sit to eat a meal (plural). |
|
Tectonic activity associated with convergent plate boundaries around the Pacific Ocean has led to the Pacific Rim being called the Pacific _______ _______ _______(3 words).
|
Ring of Fire
The trenches that occur along the margins of the Pacific Ocean are associated with subduction zones and volcanic arc volcanism, which are the dominant features of the Pacific Ring of Fire. HINT This was named because it appears on a world map as a very large circular structure that has an abundance of the world's volcanic (and earthquake) activity. |
|
The _______ coast of South America is an example of a convergent active continental margin.
|
west
The west coast of South America is considered to be a convergent-active continental margin because of the convergent plate boundary and associated trench/continental arc. HINT It's a compass direction (not left or right). |
|
Black smokers are commonly found along the crest of the _______ _______ _______(3 words).
|
mid-ocean ridge
Black smokers are associated with the crest of the mid-ocean ridge. HINT It's commonly abbreviated MOR (don't forget the dash!). |
|
Lithogenous sediments are
|
made of material derived from the continents.
Lithogenous sediments are primarily weatheredmineral grains. |
|
Where are most modern-day calcareous oozes found in the ocean?
|
along the mid-ocean ridge beneath warm surface waters
Remember that calcareous sediments will not form below the CCD. |
|
True or False? Because they tend to move downslope, most lithogenous sediments are deposited in abyssal plains.
|
False
Consider the process by which lithogenous sediments are transported. |
|
True or False? The calcite compensation depth (CCD) represents the depth where wave action ceases to form calcareous oolites.
|
False
Oolites are onion-shaped carbonate precipitates that occur in shallow, warm water. |
|
All of the following are indicators of a mature texture in lithogenous sediment, EXCEPT
|
high clay content.
Maturity can be caused by increased time of transport from source to deposit. |
|
Deep sea oozes are
|
all of the above.
Oozes contain at least 30% skeletal remains from marine microorganisms. |
|
Manganese deposits are NOT
|
a type of foraminifer.
Manganese is a metal that occurs as nodules on the sea floor. |
|
Which of the following marine organisms lives in cold, polar waters?
|
diatoms
Their skeletons are made of silica. |
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The similarity found in test populations near the ocean surface and the ocean floor, despite the 10 to 50 years it takes for an individual test to sink to the abyssal depths, can be explained by
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being concentrated in fecal pellets.
Consider effective transport agents. |
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Beneath the calcite compensation depth (CCD),
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calcium carbonate dissolves in seawater.
The physical conditions below the CCD cause something to happen to calcium carbonate material (such as calcareous ooze). |
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The only way for siliceous ooze to be preserved in the ocean is
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to have it accumulate faster than it dissolves.
Remember that silica is unaffected by the CCD but is constantly and slowly dissolving in seawater. |
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Calcareous ooze is associated with ________ surface water conditions, and siliceous ooze is associated with ________ surface water conditions.
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warm; cool .
Think of where the organisms live that produce the deposits on the sea floor below. |
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Which of the following is the most fine-grained sediment?
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abyssal clay
For sediment sizes, consult the Wentworth scale of grain size for sediments (Table 4-2, page 105 in the text). |
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The Deep Sea Drilling Project (DSDP) confirmed that
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all of the above are true.
Integrate your new knowledge of tectonics, paleomagnetism, and sediment deposition to answer this question. |
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Most chalk is made from
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coccoliths
Chalk is made of once-living microscopic photosynthetic organisms that make their hard shells out of calcium carbonate. |
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Sediments derived from pre-existing rock are called _______ sediments.
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lithogenous
Lithogenous sediments are derived from pre-existing rock material. HINT Remember, "litho" means rock. |
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The Wentworth scale provides a standard naming scheme for _______ size based on diameter.
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grain
The Wentworth scale is a grain size scale used to provide a standard naming scheme for particles. HINT The answer rhymes with "brain." |
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Marine sediments found close to shore and are characteristic of continental margins are called _______ deposits.
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neritic
Neritic (literally, "of the coast") deposits are those sediments that are found close to shore. HINT This is the opposite of pelagic deposits. |
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Sediments that contain a significant proportion of hard remains of once-living marine organisms are called _______ sediments.
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biogenous
Biogenous sediments, such as calcium carbonate or silica (opal), are derived from the hard remains of once-living organisms. HINT Remember, "bio" means life. |
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_______ are an example of a microscopic, photosynthetic, silica-secreting organism.
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Diatoms
Microscopic algae called diatoms, along with radiolarians (protozoans), comprise most siliceous biogenous particles. HINT These are the organisms that make up "diatomaceous earth" (plural). |
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The average depth of the calcite compensation depth (CCD) in the ocean is _______ meters.
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4500
The average depth of the CCD is 4500 meters. HINT It's a four-digit number with no commas that's equal to about 15,000 feet. |
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Manganese nodules are an example of _______ sediment.
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hydrogenous
Hydrogenous deposits, such as manganese nodules, form as the result of chemical reactions that take place in the water or from interactions between seawater and sediment. HINT Manganes nodules are round hard lumps of metal-rich material that precipitate directly from seawater. |
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Particles from space are referred to as _______ sediment.
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cosmogenous
Cosmogenous particles originate from outer space, and commonly include nickel-iron spherules and silicate chondrules. HINT Space is sometimes referred to as the cosmos. |
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Oozes can only form where the deposition of _______ material occurs at a very low rate.
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lithogenous
Lithogenous sediment deposition precludes the formation of an ooze, which is pelagic and must have greater than 30% by weight of biogenous material. HINT Oozes do not contain very much material derived from rocks. |
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Halite (table salt), anhydrite, and gypsum are examples of _______ sediment.
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hydrogenous
Halite, anhydrite, and gypsum form by evaporation of seawater and are examples of hydrogenous sediments. HINT These minerals form by precipitating directly from the dissolved materials in seawater. |
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Radiolarian ooze is an example of _______ sediment.
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biogenous
Radiolarian ooze is a biogenous sediment that contains at least 30 percent radiolarian tests. HINT Remember what type of sediment includes the hard remains of once-living organisms. |
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Black volcanic beach sand is an example of _______ sediment.
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lithogenous
Black volcanic beach sand is lithogenous sediment because the material that comprises the sand was originally from rock material. HINT Even though black volcanic beach sand can form by lava flowing into the ocean, the material that comprises the sand was originally from rock material. |
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The depth in the ocean at which calcium carbonate first begins dissolving is called the _______.
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lysocline
The depth at which calcium carbonate first begins dissolving is called the lysocline. HINT This is not the CCD, which is deeper below. This word is derived from "a loosening" plus "slope" (1 word). |
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Below the CCD, calcium carbonate _______.
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dissolves
At the CCD, supply rate = dissolution rate. Below this depth any calcium carbonate in the water dissolves. HINT The water below the CCD is undersaturated with regard to calcium carbonate, so this chemical reaction takes place (plural). |
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The most common type of gas hydrate is _______ hydrate.
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methane
Methane hydrate is the most common type of gas hydrate. HINT This gas has a chemical formula of CH4. |