Geology 1113 Unit 2 HW Questions

Geology 1113 Unit 2 HW Questions

Compaction will be the most significant lithification process for which of the following rocks?
shale
Which rock is the most abundant chemical sedimentary rock?
Limestone
________ processes such as evaporation and chemical activity can precipitate chemical sediments.
Inorganic
________ is a biochemical sedimentary rock that often forms in carbonate reefs.
Limestone
________ is the process where calcium ions in limestone are replaced with magnesium or small amounts of iron.
Dolomitization
Which rock type can contain fossils?
Sedimentary Rocks
________ are fragments of pre-existing materials that have been broken down through the processes of weathering.
Sediments
________ is the process where sediments are converted into a sedimentary rock.
Lithification
What is diagenesis?
The textural, compositional, and other changes that occur to sediments after deposition
Which of the following mudstones displays fissility?
shale
Which environment would be likely to produce a black shale?
swamp
Which of the following best describes the appearance and composition of a conglomerate?
Rounded fragments; poorly sorted
Which of the following represents the single most common and characteristic feature of sedimentary rocks?
Strata
A ________ marks the end of one episode of sedimentation and the beginning of another.
Bedding plane
A ________ describes how, when a sedimentary layer is examined in cross-section laterally, various parts of the layer consist of different sediments accumulating next to each other in different environments of deposition.
Facies
The primary basis for classifying detrital rocks is ________ whereas the primary basis for classifying chemical rocks is ________.
Particle size; mineral composition
________ is the process where a rock changes form or mineral content as a result of environmental changes such as heat and pressure.
Metamorphism
Which of the following is the parent rock for quartzite?
Sandstone
If clay minerals were buried at a depth where subsurface temperatures exceed 200°C, which mineral are they likely to become?
Muscovite
Which of the following lists of metamorphic rocks places the rocks in order from lowest metamorphic grade to highest?
Slate, Phyllite, Schist, Gneiss
Which of the following rocks represents the highest grade of metamorphism?
Gneiss
What kind of force will create foliation in metamorphic rocks?
Compression
Which style of metamorphism will be generated by a mantle plume?
Contact
________ metamorphism tends to occur in regions where massive amounts of sedimentary or volcanic materials accumulate in a subsiding basin.
Burial
In which geologic setting is the most widespread occurrence of hydrothermal metamorphism?
Along the axis of a mid-ocean ridge system
________ is a widespread type of metamorphism typically associated with mountain building.
Regional metamorphism
Which tectonic boundary is associated with regional metamorphism?
Convergent
________ are materials that are good indicators of the metamorphic environment in which they formed and can be used to distinguish between various zones of metamorphism.
Index Minerals
What is a metamorphic facies?
An assemblage of minerals that form in very similar metamorphic environments
Along which type of tectonic boundary will greenschists and blueschists form?
Convergent
A(n) ________ facies is associated with a high pressure, low temperature environment.
Blueschist
Metamorphic rocks can sometimes contain unusually large grains surrounded by a fine-grained matrix of other minerals. These large crystals are called ________.
Porphyroblasts
What is a fossil?
Evidence of past life that can include skeletal as well as trace material
A mammoth frozen in the Arctic tundra of Siberia would be an example of which type of fossilization?
Mummification
A worm burrow is an example of which type of fossilization?
Trace fossil
What is correlation?
Matching up rocks of similar age in different regions
When correlating rock between widely separated areas or between continents, what feature do geologists rely on the most?
Fossils
What is an index fossil?
Organisms that were geographically widespread but limited to a short span of geologic time
What is an isotope?
An atom that has more or fewer neutrons than it should
What era are we currently in?
Cenozoic
________ is a term used to define 88% of Earth’s history prior to the start of the Paleozoic Era.
Precambrian
What is the definition of relative dating?
Putting events in order from first to last
The oldest is on the bottom, the youngest on top
Superposition
Sedimentary layers/lava flows are deposited in flat layers
Original horizontality
Rock extend in all directions until they reach the edge of a basin or pinch out
Lateral continuity
Faults, fractures are younger than the rocks they cut through
Cross-cutting relationships
Missing time
Unconformities
Chunks of weathered rock are older than the rock they are contained in
Inclusions
________ is the compass direction of the line produced by the intersection of an inclined rock layer with a horizontal plane.
Strike
________ is the angle of inclination of the surface of a rock unit measured from a horizontal plane.
Dip
Which tectonic boundary would have many normal faults associated with it?
Divergent
A ________ fault is created when the hanging wall moves up relative to the footwall.
Reverse
Faults that exhibit both dip-slip and strike slip movement are called ________ faults.
Oblique-slip
________ refers to the changes in shape or position of a rock body in response to differential stress.
Deformation
Which tectonic boundary is associated with compressional stress?
Convergent
Forces pull apart from each other
Tension
Forces move toward each other
compression
Forces slide past each other
shear
Rocks will change shape due to pressure, but return to their original state when pressure is released
Elastic Deformation
Rocks will change shape permanently due to pressure
Ductile Deformation
Rocks will shatter due to pressure
Brittle Deformation
A ________ is a circular fold where the youngest layers are in the middle and the oldest layers are on the outside.
Basin
How will the outcrop pattern of a plunging syncline be oriented?
The layers will open u pin the direction of plunge
A(n) ________ fold has limbs that are tilted beyond the vertical to the point that the axial plane is horizontal.
Recumbent
Which of the following best describes the age relationship of the layers in an anticline?
Oldest on the inside of the fold, youngest on the outside
You are watching TV with a friend when there is a special bulletin about a city in California being devastated by an earthquake. The news anchor reports that the epicenter of the earthquake is 45 miles east of Los Angeles. How would you explain the definition of the epicenter to your geologically impaired friend?
The location on the Earth’s surface directly above the point of slippage
The elastic rebound associated with earthquakes is an example of ________ deformation.
Elastic
________ are smaller earthquakes of lesser magnitude that follow a major earthquake.
Aftershocks
Which tectonic boundary is associated with megathrust faults?
Convergent
Which tectonic boundary is responsible for the most powerful and destructive earthquakes recorded?
Convergent
What is the term used to describe slow, gradual displacement along a fault without the accumulation of significant strain?
Fault Creep
________ is a measurement of displacement on the fault surface.
Fault slip
Which seismic wave will be released first during an earthquake?
P-waves
Generally speaking, which seismic waves will have the greatest amplitude on a seismogram?
Surface waves
This body wave is a compressional wave.
P-waves
This body wave is a shear wave
S-waves
This surface wave moves from side to side.
L-waves
This surface wave moves up and down.
R-waves
Liquefaction will ________.
Amplify the power of seismic waves
Where is the zone of greatest seismic activity on Earth?
Circum-Pacific Belt
Which of the following best describes a seismic gap?
Unusually quiet zones along typically active faults