Geology
Which of the following is a characteristic of an S wave?
"shaking" particle motion at right angles to the direction of wave travel
Consider these real-world items. Which of them illustrates elastic rebound or behaves like rocks prior to and during an earthquake?
-Bungee Cord -A rubber eraser
What processes created the Earth's moon?
-Earth was struck by a large planetesimal -Debris from Earth and another planetesimal accreted
Which of the following area(s) is/are likely to experience an earthquake? Choose all that apply.
-Indonesia -New Zealand -Alaska -Japan
About 2.2 billion years ago, a significant amount of oxygen appeared in the atmosphere. How does this relate to life on Earth during this time and after?
-Significant amounts of oxygen in the atmosphere contributed to the formation of ozone. This protected life from ultraviolet radiation. -Photosynthesis became a successful way to convert energy from the sun, and oxygen was a significant by-product.
Which processes created the magma ocean that used to exist on the planet Earth?
-bombardment -radioactive decay
What caused the planet's temperature to rise early in Earth's formation? Choose all that apply
-decay of radioactive elements -collision of planetesimals
Fill in the blank with the appropriate word(s). Continental crust is _______ than oceanic crust. Choose all that apply.
-thicker -less dense
Assume the dolls are each 4 centimeters tall. Measure the extent of displacement by using the height of one of the dolls as your scale. How much displacement (in meters) has occurred? Note that: 1 doll = 4 cm 1 meter = 100 centimeters
0.4 meters
The Colorado River has carved the Grand Canyon to a depth of __________ and length of __________.
1 mile; 277 miles
Drag the appropriate items into their respective bins. Each item may be used only once.
1. Mexico City = approximately 4 minutes 2. New York City = approximately 5 minutes 3. Nome = approximately 6 minutes
The S wave arrives 3 minutes after the P wave, so the epicenter is approximately_______miles away.
1250
When did Pangea begin to break into smaller fragments?
180 million years ago
How much material was removed from the volcano?
2.8 cubic kilometers of rock
The S wave arrives 1 minute after the P wave, so the epicenter is approximately________ miles away.
250
The S wave arrives 5.5 minutes after the P wave, so the epicenter is approximately_______ miles away.
2500
Which of the following is a possible distance of the asteroid belt in our solar system from the Sun?
3 AU
The rock that makes up ocean basins has a density of ________ and is made of ________.
3.0 g/cm3; basalt
Which of the following is a possible distance of the Kuiper Belt from the Sun?
50 AU
Refer to the accompanying seismogram in Part A again, and determine the time interval between the arrival of the first P wave and the arrival of the first S wave.
6 minutes
Which of the following pieces of evidence for a past volcanic eruption are present at Yellowstone National Park?
A caldera rim Lava flows Pyroclastic material
What is an anticline?
A fold shaped like an upside down U
The nebular theory is the most widely accepted view of the origin of our solar system. Which of the following is a short description of the nebular theory?
A large cloud of space gas and dust condensed and contracted to form a rotating disk with a star formed at the center. Repeated collisions caused bodies to coalesce, leading to the current configuration of our solar system.
Which of the following objects has a size similar to that of lapilli?
A marble (15 mm)
Which of these most directly triggered the main eruption?
A massive landslide
What is the D" layer?
A partially molten layer above the outer core at the base of the mantle.
Define earthquake intensity.
A qualitative measure of the amount of ground shaking at a certain location.
Which of the following statements about the rock cycle is correct?
A sedimentary rock subjected to intense heat and pressure will become a metamorphic rock.
__________ is a seismic zone that has not produced a large earthquake for a considerable length of time.
A seismic gap
What causes the same mineral to occur in varieties that are different colors?
A small amount of impurities in the crystal structure.
Which of the following is true about a tsunami?
A tsunami causes a rapid withdrawal of water from beaches as it approaches the coast.
What is a plume
A zone of upwelling material originating at the outer core mantle boundary
What is the difference between aa lava and pahoehoe lava?
Aa lava has a prickly texture; pahoehoe has a smooth, ropy texture.
What main characteristics are used to distinguish the two types of mountain belts?
Age and degree of erosion
How did erosion affect Shiprock?
All of the lava and pyroclastic material and some of the volcanic neck were eroded.
Yellowstone is best described as which of the following?
An active volcano that has erupted in the last 1 million years
Describe how sand volcanoes form.
An earthquake causes loose, saturated sandy material to liquefy, shoot upward through fractures of a confining unit, and eventually erupt at the surface.
The composition of the rocks that make up Shiprock would most likely be similar to which of the following rocks?
An igneous rock associated with continental volcanic activity
The __________ is an example of an old mountain belt, while the Himalayas represent a(n) __________.
Appalachian Mountains; young mountain belt
Look at the figure below showing a slice through Earth's interior again. There is one layer in Earth that will transmit only one type of wave based on its composition. Select the layer from A, B, and C that doesn't transmit all waves.
B the outer core
Which of the following rocks best represents the typical composition of oceanic crust?
Basalt.
Which of the following responses best describes why the lithospheric plates are able to move around on the surface of Earth?
Because the asthenosphere is composed of weak, hot, and dense rock, the cold, rigid, less dense lithospheric plates are capable of moving on it.
What causes a lack of cleavage and some minerals
Bonds of equal strength in all directions
Which of the following scenarios best describes the deformation that will occur in different parts of the crust?
Brittle deformation is dominant in the shallow crust; ductile deformation is dominant in the deep crust.
Put the following events in the order they occurred to lead to the formation of the solar system:
C. Hydrogen and helium formed atoms. A. Earth was bombarded by new materials after formation. B. Earth separated into layers based on the weight of materials. D. Outgassing of volcanoes produced a primitive ocean.
What mineral is not scratched by a fingernail, but is scratched by a copper penny?
Calcite
How do calderas form?
Calderas form when the summit of a volcano collapses.
Which mountain range, formed via continental convergence, developed just before the Appalachians of North America?
Caledonian Mountains
Which of the following correctly states the order in which major features of North America were formed?
Canadian Shield, Appalachians, North American Cordillera
Which mountainous range is not the result of continental collision?
Cascades
What are the two important processes involved in lithification of sedimentary rocks?
Cementation and compaction
The layers of Earth are based on what two sets of characteristics?
Chemical composition and physical properties
What type of volcanic cone is illustrated in the Gigapan image?
Cinder cone
What is one way that cinder cones differ from composite and shield volcanoes?
Cinder cones are smaller than composite and shield volcanoes.
Which of the following best describes the term cleavage?
Cleavage of the splitting of minerals along natural plains of weakness
Which of the following is the volcanic feature in which magma rises through before it is released at the surface?
Conduit
Suppose you found a mineral crystal that looked like topaz. What two minerals could you use in a scratch test to help determine if the mineral is needed topaz?
Corundum and quartz
Which of the following was a stage in the formation of Yellowstone caldera?
Crust bows upward above a magma chamber.
How did the density and buoyancy of the materials that formed Earth affect its internal structure? View Available Hint(s)
Denser materials, such as nickel and iron, sank to the Earth's center and became its core, whereas less dense, more buoyant materials such as silicon and aluminum, rose to the Earth's surface and became its primitive crust.
Name the hardest and softest mineral on the mohs scale
Diamond(hardest) and talc(softest)
Which of the following terms best characterizes upwelling in the asthenosphere
Diffuse
Which of the following describes a trend that occurs with increasing distance from the Sun?
Distance between planets increases.
At what point during a meterite impact are rock layers overturned
During rebound layers of rock after impact
Which of the following statements describes how metallic bonding occurs?
Each atom donates its valence electrons to a common pool of electrons that are free to move throughout the entire structure.
Why is Earth the only planet in the solar system that can support life?
Earth is close enough to the Sun that water is found in liquid form.
Which of the following responses provides the best reason for why the asthenosphere is not capable of storing elastic energy?
Elastic energy can only be stored in cold, brittle rocks.
What is the category name for the largest division of time used on the geologic time scale?
Eon
The Ural Mountains were formed by the collision of which continents?
Europe and Asia
Considering how magma composition, temperature, water content, and volatile content affect its viscosity, associate each of the volcanoes described in this activity with the type of eruption it should produce, or indicate whether the described characteristic is not related to eruption style.
Explosive eruption~ Volcano fed by silica-rich magma Nonexplosive eruption~ Volcano fed by mafic (basaltic) magma, Volcano fed by magma with low amounts of dissolved gases, Volcano fed by high-temperature (1000∘C) magma Unrelated to eruption~ Volcano that has not erupted for a long time, Volcano at high elevation (>10,000 feet above sea level)
What accounts for most tectonic plate motion
Forces at subduction zones
Which of the following exhibits three sets of cleavage at 90° angles?
Galena
Aside from avoiding geologic hazards, why else do we study geology?
Geology is also studied to learn how to locate and extract resources that are necessary for life and industry.
Why glass is not considered a mineral?
Glass has a disorderly atomic structure.
What are the two most important driving forces of metamorphism?
High heat and pressure
What features at the surface provide evidence of plumes
Hot spots
If previous eruptions had left Mount St. Helens with a different shape, what differences might have influenced the timing of the eruption?
If the northern slopes had been less steep initially (same height), the eruption would likely have happened later. If the volcano had been significantly shorter initially (same steepness), the eruption would likely have happened sooner.
What is the relationship between temperature and density
In general warmer materials are less dense and colder material are denser
Which of these are true about intraplate volcanism?
Intraplate volcanism usually erupts basaltic lava. Intraplate volcanism occurs both on continental and oceanic landmasses.
_____ igneous rocks are those that cool below the surface.
Intrusive
_____ is the principle that explains why materials uplift to a certain elevation.
Isostasy
What makes Erta Ale so unique among other active volcanoes in the world?
It is one of only a few volcanoes that have permanent lakes of molten lava in their craters.
All of the following criteria define a mineral except:
It is organic.
Which planet in the solar system had more mass accreted to it via a comet that impacted in 1994?
Jupiter
Imagine you are a geologist charged with the task of choosing which sites listed below should get state-of-the-art volcano monitoring systems. Which of the volcanoes below is least in need of monitoring?
Kuai, Hawaii
Which of the following volcanic materials flows out of a volcanic vent?
Lava
Which of the following combinations is the correct order of the layers of Earth from the surface to the center?
Lithosphere, mantle, outer core, inner core
The amount or quality of light that is reflected from a mineral surface is known as __________.
Luster
Since color is not a very useful way to identify a mineral,what other optical porppert or properties can be used?
Luster and streak
What is the difference between magma and lava?
Magma is molten rock located below the surface; lava is molten rock erupted above ground
Which of the following is a good example of a shield volcano?
Mauna Loa in Hawaii, USA
The Jurassic Period lies in the _____ Era, which was dominated by large terrestrial vertebrates, or _____.
Mesozoic; dinosaurs
An igneous rock becomes buried, is subject to high heat and pressure, and recrystallizes. This rock then is eroded, transported, deposited and subsequently lithified. Which rock types—in order—did the original igneous rock develop into?
Metamorphic and sedimentary
Why is meteor crater so well preserved
Meteor crater is relatively young
Volcanic ash is best described as which of the following?
Microscopic pieces of rock ejected by a volcano
Regardless of their size, most rocks are made up of __________.
Minerals
A scientist creates diamonds using high-pressure laboratory experiments. These diamonds are not considered minerals because which of the following requirements has been violated?
Minerals must occur naturally.
Why is moment magnitude (MW) preferred over Richter magnitude (ML)?
Moment magnitude measures the total energy released during an earthquake and can adequately measure the energy of large earthquakes.
What is a large, step-like fold in otherwise horizontal strata called?
Monocline
Along which features might one expect to see a deep-ocean trench?
Mountain ranges
There had been many earthquakes in the area prior to this eruption. Why did this last earthquake trigger a massive landslide?
Moving magma had over-steepened the mountain slopes.
Focus in on the light brown areas in the foreground where the students placed the small, plastic figures. What is the name given to this type of sedimentary structure, and what does it indicate about the environment?
Mud cracks—indicate drying out of wet mud
Imagine a fold has been eroded to a flat surface. In general, how would you know whether this fold is plunging?
Non-plunging folds look like straight lines at the surface, and plunging folds look like wavy lines.
Look, again, at the map. Which segment do you think is experiencing fault creep? Faults that creep have slow and continuous rock movement instead of the sudden and large movement associated with earthquakes.
North central section (orange on the map) **Along the San Andreas Fault in central California, "creepmeters" are used to measure the amount the fault slips every 10 minutes.
Refer to the map of Earth's plates below, and determine which type of plate boundary is most often associated with these earthquake events.
Ocean-continent convergent (subduction) boundaries
What are the two types of crust?
Oceanic and continental
Now, examine the outcrop in the Gigapan image again. Observe each side, or limb, of each fold. Compare the steepness of each limb's dip to determine whether the fold is symmetrical or asymmetrical. Next, review the statements below, and indicate which are correct for the style of folding present in the Gigapan image. Select all that apply.
One side of the anticline dips more steeply than the other. At least one of the folds in this outcrop is asymmetrical.
Which of the following layers of Earth generates the magnetic field?
Outer core
The magnetic field of Earth is thought to originate in which of the following layers?
Outer core.
Use the accompanying seismogram to answer which of the three types of seismic waves reached the seismograph first.
P wave **P waves are so fast that they can travel through Earth's mantle in about 20 minutes.
Which of the following features would you find in an ocean basin? CHOOSE ALL THAT APPLY.
Peru-Chili Trench Mid-Atlantic Ridge
In which division(s) of time are we currently living? Please be as specific as possible.
Phanerozoic eon, Cenozoic era, Quaternary period, Holocene epoch
As you learned above, this area used to be wetter than it is today. Which of the following desert landforms best describes the light-colored area in the foreground of the photo?
Playa
Which of the following accurately describes a difference between protons and electrons?
Protons have a positive electrical charge, while electrons have a negative electrical charge.
What causes a central peak to form in an impact crater?
Rebound of the rock layers after impact
Imaging a syncline has been eroded to a flat surface. How would the rock age change as you walked across that flat surface?
Rocks would be oldest on the edges and youngest in the middle.
Imagine an anticline has been eroded to a flat surface. How would the rock age change as you walked across that flat surface?
Rocks would be youngest on the edges and oldest in the middle.
Richter magnitude (ML) is derived from measuring _____ and _____, and then plotting them on a Richter diagram.
S minus P wave time; maximum S wave height
Which of the following rock types is most abundant on Earth's land surface?
Sedimentary rocks
geological rock cycle
Sediments - lithification - sedimentary rocks - burial metamorphism - metamorphic rocks - melting - cooling - igneous rocks - weathering and erosion
What is NOT true about seismic waves?
Seismic waves travel along a straight path.
What does the volcano's name, Erta Ale, mean in the local Afar language?
Smoking Mountain
Using the accompanying map of the San Andreas Fault, and the knowledge that earthquakes occur about every 200 years in this area, which of the four segments of the fault do you think has the best chance of experiencing a major earthquake in the near future?
Southern section (bottom section, red on the map)
Which of the following correctly compares the seismograph readings from Station 1 to Station 2, as shown in the video?
Surface waves show smaller amplitude at Station 2.
What would happen to the Earth if it orbited further away from the Sun than it does now?
The Earth would have a lower surface temperature.
What does the Hawaiian Island-Emperor Seamount chain indicate about past movement of the Pacific plate?
The Pacific plate changed direction of movement about 50 million years ago.
Why is the geologic time scale more detailed in the Phanerozoic than in previous eons?
The Phanerozoic Eon is more detailed because of the presence of organisms with hard parts and the rapid increase in. biodiversity
What object or class of objects makes up most of the solar system's mass?
The Sun
The upper mantle can be divided into the asthenosphere and lithosphere based on what physical properties?
The asthenosphere is solid, but mobile, while the lithosphere is solid and relatively rigid.
What happens to the atmosphere as you move away from Earth's surface?
The atmosphere thins.
If the age of a mountain range is inversely proportional to its height, in what two regions are the youngest mountain ranges found today?
The circum-Pacific belt and southern Europe/Asia
Which of the following best describes the term streak?
The color of a powdered form of a mineral produced by rubbing it across a hard surface.
Which physical feature represents the true transition from the continent to the ocean basin?
The continental slope
Using what you know about isostasy, how would the crust behave if a large glacier were removed?
The crust would move up in elevation.
Which one of the following is true regarding the effects of Glen Canyon Dam on the Grand Canyon?
The dam traps sediment that previously had been carried downstream.
Which of the following best describes why the 2010 earthquake in Chile caused a large tsunami while the 2010 earthquake in Haiti only caused a small and local tsunami?
The earthquake in Haiti was the result of motion on a transform boundary, which does not produce any vertical motion of the sea floor, while the Chilean earthquake was the result of motion along a convergent plate boundary, which does.
In addition to rock deposits, what evidence do we have that the eruption that preceded the formation of Crater Lake was very large?
The eruption was so large that the magma chamber under Crater Lake partially emptied, causing the volcano to become unstable and collapse.
Which of the following best explains the formation of the four inner (terrestrial) planets?
The inner planets formed form the repeated collision of planeteismals
The enormous cloud of gas and dust initially condensed due to particle attraction. What force then pulled the cloud into a flat disk shape?
The inward pull of gravity
How do the lithosphere and asthenosphere differ?
The lithosphere is a cool, rigid outer shell that overlies the asthenosphere, which is softer and weaker than the lithosphere.
Why must geologists understand the magnitude of geologic time?
The magnitude of geologic time spans billions of years and thus differs greatly from the magnitude of time people deal with on an everyday basis (e.g., hours, weeks).
Using a calendar year as an analogy to the geologic time scale, when do the oldest anatomically modern humans appear on Earth?
The oldest human fossils show up at about eleven minutes to midnight on December 31st.
What geologic event led to the formation of the rocks that make up Shiprock?
The rocks in Shiprock formed when magma solidified in the neck of an old volcano.
If the Rocky Mountains were eroded, what would happen to the roots of the mountains?
The roots would rebound upward.
If stable platforms represent sedimentary rocks that cover continental shields, then what statement must be true?
The sedimentary rock atop the stable platforms must be younger than continental shields.
Which of the following best describes liquefaction?
The transformation of stable soil into loose, liquefied material that is able to rise toward Earth's surface
The Afar region is one of the most environmentally challenging areas on the planet. The geopolitics of Afar are equally challenging. Why?
There are many bandits in the region, who contribute to the instability and danger of the region.
How did the ridges around Shiprock form?
They are old dikes radiating from the main neck of the volcano
Which of the following describes the inner planets of our solar system?
They contain mostly iron, nickel, and rock-forming minerals.
Which of the following statements is true of composite volcanoes?
They erupt silica-rich lavas that cool to andesite or rhyolite.
Considering how magma composition and temperature change as it rises toward the surface, categorize each of the magmas described below in terms of their position within the lithosphere and uppermost asthenosphere.
Upper Lithosphere / crust ~ Magma with density equal to or less than the crust, Magma with greatest silica content, Magma undergoing degassing during an eruption Lower Lithosphere ~ Magma with density less than the lower lithosphere but higher than the crust, Magma undergoing partial crystallization of high-density minerals Asthenosphere ~ Magma with the highest temperature
What happens to tsunami waves as they move closer to shore?
Velocity decreases and height increases.
Which statement accurately describes continental shields?
Very old, stable regions composed of igneous and metamorphic rocks
Name the epoch, period, era and eon in which we currently live.
We live in the Holocene Epoch of the Quaternary Period, which is part of the Cenzoic Era and Phanerozoic Eon.
Which of the following features at Yellowstone National Park is evidence for a magma chamber beneath the park?
Welded tuff Rising (or bowing upward) ground near Yellowstone River Geysers and hot springs (steam)
What does a turbidite sequence consist of?
a blanket of sand overlain by a sheet of mud
Which of the following describes an accretionary wedge?
a chaotic accumulation of sediments and scraps of ocean crust
What produces plunging folds?
a combination of folding and tilting
The distinctive lava flow pattern in Erta Ale's crater is important because it is similar to the processes occurring deep inside the earth. The repetitive process whereby magma rises from the mantle, cools and solidifies, and then sinks and liquefies is called __________.
a convection current
What is convection?
a cycle of moving material formed by the rise of less-dense material and the sinking of denser material
What does the term plunging fold mean?
a fold that is tilted down into Earth
The mineral fluorite is an example of:
a halide mineral.
What kind of geologist studies fossils?
a paleontologist
Which feature is not considered a rock structure?
aa
What term describes lava that has rough, jagged surfaces with sharp edges?
aa lava
biosphere
all life on the planet
Which of the following extra solar planets would likely have an atmosphere?
an Earth-sized planet located farther away from the Sun
If all were accessible, which of the following items would be best for geologists to examine to better understand Earth's internal structure?
an iron meteorite
If a rock undergoes folding and is compressed to form an upward arch, this is a(n) ___________ type fold.
anticline
How far away from the Sun would a planet Mercury's size have to be before it would have an atmosphere?
as far away as Jupiter
The air we breathe is part of the __________.
atmosphere
What is a continuous or broken ring of coral reef that surrounds a central lagoon called?
atoll
Which one of the following statements is NOT true about andesite and basalt?
basaltic lava is thicker than andesitic lava
Regardless of their size, most rocks are made up of __________. Minerals
be generally inorganic in origin
Why does a volcano fed by highly viscous magma pose the greatest threat to life and property?
because potential eruptions are highly explosive and less predictable
The distance between a seismic station and an earthquake can be determined by the interval between the arrival of the P wave and the arrival of the S wave, as shown in the graph below. Using the data in the seismogram in Part A and your answer to Part B, compute the distance from the seismic station to the earthquake with the accompanying travel-time graph.
bout 3000 miles or 4800 kilometers
The doctrine of ______ held that the major features of the surface of the earth were created by sudden, short-lived, violent events.
catastrophism
When contrasting catastrophism with uniformitarianism,
catastrophism was published first, and it proposed that Earth's landscapes were formed by catastrophic events. On the other hand, uniformitarianism was published over a century later and proposed that the physical, chemical, and biological processes that operate today have also operated in the geologic past.
What is piled up along the cone of SP Crater that causes it to be so steep?
cinders
Which of the following would NOT be classified as a mineral?
coal
A smaller earthquake in Virginia was felt over a larger distance, as compared to a larger earthquake in California. What is the reason this occurred?
colder crust
What type of volcano is Mount St. Helens?
composite
What best describes the movement of P waves?
compression and expansion
Which type of force is responsible for reverse fault formation?
compressional force
Quartz exhibits __________.
conchoidal fracture
Which type of stress on rock is uniform in all directions?
confining pressure
Which type of plate boundary is most associated with Earth's major mountain chains?
convergent plate boundaries
What type of volcanism is associated with the zone of active volcanoes called the Ring of Fire?
convergent plate boundary volcanism
Which of Earth's layers is thought to be composed mostly of iron-nickel alloy?
core
What are the three major layers of Earth from its center to its exterior?
core (an iron-nickel alloy), mantle (which is composed mainly of peridotite), and crust (with a granitic or basaltic composition)
A ________ is the interior of a continental mass that has been relatively undisturbed for the last 600 million years.
craton
Which type of stress produces most crustal deformation?
differential stress
What type of deformation is shown in the Gigapan image?
ductile
As stress is applied to rocks and deformation occurs, which of the following terms best characterizes the energy that is stored in the process?
elastic energy
From the list of terms below, choose the ones associated with the fault you observed in the Gigapan image.
extension of the crust tensional environment normal fault
Through the course of time, bodies in our solar system have become __________ and __________ due to collisions
fewer in number; larger in size
Through the course of time, bodies in our solar system have become __________ and __________ due to collisions.
fewer in number; larger in size
atmosphere
gaseous envelope around the planet
Which of the following minerals belongs to the non-silicate mineral group known as oxides?
hematite
The ratio of silicon to oxygen atoms in silicate minerals depends on:
how the atoms in silicon-oxygen tetrahedra are shared.
Groundwater dissolving limestone bedrock is an example of interactions between the _______.
hydrosphere and geosphere
A(n) ___ is a tentative explanation, whereas a(n) ____ has survived extensive scrutiny over many years.
hypothesis; theory
Which of the following is a mineral?
ice
What is the basic foundation of Moh's hardness scale?
if a mineral scratches an object , then the mineral is harder than the object
The external expression of a mineral's orderly internal arrangement of atoms is referred to as:
its crystal form.
When a rock is under undue stress and fractures but there is no movement to either side of the fracture, the feature is a called a __________. If, however, there is movement, it is called a _____________.
joint, fault
Which of the following items is made from a renewable resource?
lumber boards
Which layer of Earth possesses the greatest thickness?
mantle
What are stromatolites?
mats of blue-green algae that grew in mounds up from the sea floor
The property of cleavage reflects:
mechanical breakage along planes of weakness within the mineral.
A __________ is located at a plate boundary between a subducting slab of oceanic crust and an overlying plate.
megathrust fault
Large rifts or valleys, which can often have very large ___________ faults, are created by tensional forces.
normal
Which of the following is a feature of a divergent plate boundary? Choose all that apply
oceanic ridge, Rift Valley
Earthquakes with a deep focus are most often associated with which of the following tectonic settings?
oceanic trenches
The silicon-oxygen tetrahedron contains:
one silicon atom and four oxygen atoms.
In addition to silicon, every silicate mineral contains what element?
oxygen
Which gas was missing from Earth's early atmosphere?
oxygen
What iron-and magnesium-rich rock makes up most of the upper mantle?
peridotite
A ________ is a part of the craton that is covered by a thin covering of sedimentary rocks.
plaform
What can seismologists determine from the process of triangulation?
precise location of the epicenter
The principal mineral used in making glass is:
quartz
Which of the following substances is a mineral?
quartz
In the field, you find an unidentified mineral that is clear, exhibits conchoidal fracture, and can scratch glass. This mineral is most likely:
quartz.
Which of the following characterizes a typical eruption of Kilauea Volcano in Hawaii?
quiet outpourings of fluid lavas
Hardness describes a mineral's
resistance to being scratched
Which of the following is an example of how rocks will respond to compressional stress? (Note: there may be more than one correct answer.)
reverse faulting folding
Which type of force is responsible for normal strike-slip formation?
shear force
The flat stable interior of a continent within a craton is called a ____.
shield
The stable interior of a continent is called a ____.
shield.
Which of the following is one of the two most abundant elements in the continental crust?
silicon
Which of the following mechanisms is the largest contributor to plate motion?
slab pull
Which type of fault has NO vertical motion of rocks associated with it?
strike-slip fault
What caused metamorphism to occur in the Blue Ridge District during the Alleghanian Orogeny?
strong differential stress generated by compressional stress was rocks were thrust westward
referring to the accompanying seismogram, which of the seismic waves had the highest amplitude when it reached the seismic station?
surface waves **The surface waves have the highest amplitude and correspond to the amount of shaking at the surface.
What term refers to a zone where two crustal fragments are "welded" together?
suture
A trough, or downward fold, called a(n) _____________ is formed when a rock is deformed through folding.
syncline
What is the geologic term for folded rocks with the bend at the bottom?
syncline
Which tectonic stress will result in a lengthening of the crust?
tension
Which type of force is responsible for normal fault formation?
tensional force
What does the Great Unconformity represent?
the billion years of Earth history from which there are no evidential rocks at the Grand Canyon
In silicate minerals, the type of cleavage or fracture is influenced by:
the bonding of the silicon-oxygen tetrahedra within the mineral.
Which layer of the Earth is the thinnest?
the crust
What are rocks below and above a fault called?
the footwall below and the hanging wall above
Which of the following accurately describes the motion of lava in Erta Ale's crater?
the lava wells up on one side of the crater and forms a dark crust. As the crust cools, it flows across the lake driven by the churning lava below. Once it flows across the lake, the crust sinks down and the process begins again.
he largest layer (by volume) of Earth, ____, is composed primarily of _____.
the mantle; peridotite
What forms the core of coral atolls?
the margins of volcanoes
What theory describes how our solar system was created?
the nebular theory
geosphere
the solid Earth
Hydrogen and Helium would have been the first elements to form after the Big Bang. How were heavier elements produced?
the supernova of early stars
why does Crater Lake have an island in it
the volcano is still active, and a new volcanic peak has formed
Why do scientists collect data?
to prove or disprove a hypothesis
What causes vesicles to form in lava?
trapped gas bubbles
Which of the following features would you find in an ocean basin? Choose all that apply.
trench, mid-oceanic ridges, abyssal plain
Hornblende has _____ cleavage planes at _____ angles.
two; non-90°
Batholiths, such as those that make up the Sierra Nevada Mountains of California, form at great depth in the crust. How could they have been exposed at the surface?
uplift and erosion
What geologic process is related to caldera formation?
volcanism
hydrosphere
water portion of the planet
The names primary and secondary refer to ___________.
wave speed
Sedimentary rocks are formed from igneous rocks beginning with the process of _____.
weathering
Which of the following locations on the Circum-Pacific Belt are likely to generate a tsunami?
west coast of South America
Which region of Earth is composed of abundant amounts of granite?
Continental crust.
Amongst all seismic waves, surface waves __________.
have the slowest velocity
Which of the following statements describes a cinder cone volcano?
They form over short periods of time, often after a single eruption event.
If major earthquakes occur along active segments of the San Andreas Fault about every 200 years, when can another major event be expected along the Fort Tejon section?
This segment should generate another major event around 2050-2060.
_____ in the sandy layer causes the ground to subside after sand volcanoes form
Tighter packing
What is a syncline?
A fold shaped like a right-side-up U
A tsunami is caused by __________
anything that displaces water
What is a fault?
fractures along which rocks move
structures build on _____ will become unstable during an earthquake.
loose, saturated sediments
How old is Earth?
4.6 billion years old
Which type of force causes folding?
Compressional force
Where is Crater Lake?
Oregon