Geology 101 Finals Study

The Principle of _ state that the physical, chemical, and biological processes at work shaping the Earth today have also operated in the geologic past.

uniformitarianism

What is the accepted age of the Earth?

4.6 billion years

What percentage of the Earth is covered by oceans?

71%

What is though to be the date of the formation of the universe?

13.7 billion years

What is the definition of differentiation?

Separation of material based on density

What property of the crust allowed it to form as the exterior of Earth?

Materials that make up the crust are less dense and rose to the top

What provides us with the most information about the interior of the Earth?

Seismic Energy Waves

Which layer of the Earth is the thinnest?

Crust

Which layer of the Earth is the thickest?

Mantle

What is the definition of the asthenosphere?

A soft, low-velocity layer in the Upper Mantle

What is the name of the theory that describes the formation of the universe?

Big Bang Theory

Which of the three most abundant elements in the universe has the highest percentage?

Hydrogen

What environmental condition had to change before subatomic particles could come together and form the first atoms after the Big Bang?

Temperature had to decrease so the subatomic particles could join into an atom

Which process is responsible for oxygen in the atmosphere today?

Photosynthesis

What is a craton?

The oldest part of a continent that has not been significantly deformed for 600 million years

Which of the following organisms is defined as a primitive organism that reproduces asexually and lacks an organized nucleus?

Prokaryote

Which mineral resource is the main component for plaster and drywall?

Gypsum

_ is the process where materials separate into different layers due to density.

Differentiation

Where is oceanic crust generated?

Along divergent plate boundaries

Of the three mechanisms of heat transfer, which is the only one that does not operate in the interior of the Earth?

Radiation

Thermal springs known as _ are often associated with oceanic ridges, where hat water containing dissolved minerals gushes from the seafloor.

black smokers

What is the definition of orogenesis?

Processes that collectively form a mountain belt

According to the plate tectonics model, most global mountain ranges are associated with which kind of plate boundary?

Convergent

Which style of convergent boundary will characterize an Andean-type mountain building event?

Where oceanic lithosphere sub-ducts beneath continental lithosphere

What is the name of the supercontinent proposed by Alfred Wegener?

Pangaea

Which plate boundary accounts for the smallest percentage of all plate boundaries on the surface of the Earth?

Transform Boundaries

Continental crust is mainly composed of _ whereas oceanic crust is mainly composed o _.

Granite; Basalt

A location where continental rifting is occurring today is _.

East African Rift Valley

What is a mantle plume?

An upwelling of hot material from the Earth’s interior that is cylindrical in shape

What generates the heat necessary for convection in the Earth?

Decay of radioactive materials

Which of the following is not part of the definition of a mineral?

Organic

A _ is a solid, naturally occurring, cohesive substance composed of minerals or mineral-like materials.

Rock

An isotope of Oxygen has 8 protons, 10 neutrons, and 8 electrons. What is the atomic mass of this isotope?

18

What is an ion?

An atom that has more or fewer electron than it should

Which is the strongest of the atomic bonds?

Covalent

Crystallization of molten rock will produce _ rocks.

Igneous

Which of the following is the hardest known natural substance?

Diamond

Which identification technique would be best to identify calcite?

Effervescence

_ is defined as a mineral’s resistance to scratching.

Hardness

Which of the following minerals has good cleavage in two directions?

Plagioclase

Conchoidal fractures are indicative of the mineral _.

Quartz

The _ are the mineral class that accounts for more than 90% of the Earth’s crust.

Silicates

A(n) _ is a silicate structure where no silica tetrahedra share any oxygen ions.

Independent

Ferromagnesian minerals are those that contain a great deal of _.

Magnesium and Iron

What are the two groups of feldspar minerals called?

Potassium Feldspar and Plagioclase

What is the mineral name for table salt?

Halite

What was the rate of cooling and the environment of formation for an extrusive igneous rock?

Fast because it was erupted from a volcano

Which of the following minerals is not a ferromagnesian mineral?

Potassium Feldspar

Which two Minerals define a felsic composition?

Quartz and Potassium Feldspar

Which igneous texture has visible crystals that are only a few millimeters across?

Phaneritic

Which of the following textures would be the most common texture found in a volcanic lava flow

Sodium and Calcium

Which of the following textures would be the most common texture found in a batholith?

Phaneritic

_ is a felsic igneous rock with a meringue-like vesicular texture created by small shards of volcanic glass

Pumice

What is the term used to describe increased temperature with depth in the Earth?

Geothermal gradient

_ describes how an entire suite of silicate minerals can form from a single basaltic magma as it cools and crystallizes.

Bowen’s Reaction Series

Which mineral on the Bowen’s Reaction Series will be the first to melt if an igneous rock is heated?

Quartz

What is the name of the pre-existing rock that is displaced by intrusive igneous bodies?

Country Rock

A _ is a tabular, concordant pluton that is nearly horizontal and forms when magma exploits a weakness between sedimentary layers.

Sill

Define magma.

Molten rock that contains dissolved gases and some crystals

_ is a material’s resistance to flowing.

Viscosity

Which of the following lavas make up 90% of the total volume of lava on Earth?

Basaltic

What is the name of the small holes created by gas bubbles on the surface of scoria?

Vesicles

A _ is a cone-shaped structure created by successive eruptions of volcanic materials such as lava or pyroclastic materials.

Volcanic cone

With the exception of volcanoes associated with a subduction zone, most volcanic islands are _ volcanoes.

Shield

In order to cover such large expanses of seafloor, shield volcanoes erupt _ lava.

Basaltic

A _ is a submarine volcano.

Seamount

Lavas erupting from composite cones are generally _ -rich, making them very viscous.

Silica

The Ring of Fire is a narrow zone of composite cone volcanoes rimming the _ Ocean.

Pacific

What kind(s) of lava are most closely associated with composite cones?

Andesite

What is the driving force behind pyroclastic flows?

Gravity

What kind of volcano is most closely associated with pyroclastic flows?

Composite Cone

What kind of viscosity would flood basalts have?

Low viscosity

An example of a volcanic caldera that formed from the collapse of a magma chamber after large volumes of material were erupted is _.

Yellowstone

Along which tectonic boundary will chains of composite cone volcanoes be located?

Convergent boundary

What type of lava is produced at a divergent plate boundary?

Basaltic

_ is when physical forces break solid rock into smaller sediments.

Mechanical weathering

_ is when there is a chemical transformation of rock into other compounds.

Chemical Weathering

What is the most important agent of chemical weathering?

Water

Which acid is commonly responsible for the dissolution of limestone?

Carbonic

Which chemical weathering process is the primary method of weathering for feldspars?

Hydrolysis

Rainwater will combine with which atmospheric gas in order to create carbonic acid?

Carbon Dioxide

Which climate contains the optimum environment for chemical weathering?

Warm and wet

_ is the upper few feet of regolith that contains minerals and organic matter, water, and air and is capable of sustaining life.

Soil

Which rock type can contain fossils?

Sedimentary Rocks

_ are fragments of pre-existing materials that have been broken down trough the processes of weathering.

Sediments

Which of the following makes up the sediment that forms an organic sedimentary rock?

Shells and plant fibers

_ is the process where sediments are converted into a sedimentary rock.

Lithification

Which environment would be likely to produce a black shale?

Swamp

Which of the following methods of transportation will result in the coarsest sorting (poorest sorting)?

Glaciers

_ describes the range in particle sizes in a detrital sedimentary rock.

Sorting

Which of the following best describes the appearance and composition of a conglomerate?

Rounded fragments; poorly sorted

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

The primary basis for classifying detrital rocks is _ whereas the primary basis or classifying chemical rocks is _.

Particle size; mineral composition

A _ describes how, when a sedimentary layer is examined in cross-sectionlaterally, various parts of the layer consist of different sediments accumulating next to each other in different environments of deposition.

Facies

A _ marks the end of one episode of sedimentation and the beginning of another.

Bedding plane

_ 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 tock for quartzite?

Sandstone

Which low-grade metamorphic rock will display fine rock cleavage and contains very fine grains of mica?

Slate

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

What is foliation?

Roughly parallel layers of mineral crystals aligned perpendicular to the direction of pressure.

_ 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

What is the definition of relative dating?

Transform

A(n) _ is a type of unconformity with parallel beds above and below the erosional surface.

Disconformity

What is a fossil?

Evidence of past life that can include skeletal as well as trace material

_ is the scientific study of fossils.

Paleontology

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

The principle of _ states that organisms succeed one another in a definite, determinable order that can be used to recognize a specific time period.

Fossil Succession

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

If 235U has 92 protons, how many neutrons does it have?

143

_ is a technique where the decay rate of radioactive isotope is measured and used to determine the age of a geologic material.

Radiometric Dating

What is the definition of a half-life?

The time it takes for half of the parent isotope to decay to the daughter

Which 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

Which of the following is the best description for structural geology?

Study of rock deformation in response to tectonic forces

Which tectonic boundary is associated with compressional stress?

Convergent

A rubber band being stretched in preparation to fire across the room is an example o what kind of deformation.

Elastic deformation

What is a fault?

A fracture in a rock along which motion has occurred

You are sitting in class when our professor begins talking about a dome with inner layers dating back to the Tertiary and its outer layers dating back to the Permian. You immediately know this professor is wrong. What is your evidence?

Domes have the oldest layers in the middle, not the youngest

A(n) _ fold has limbs that are tilted beyond the vertical to the point that the axial plane is horizontal.

Recumbent

Which tectonic boundary would have many normal faults associated with it?

Convergent

A _ fault is created when the hanging wall moves up relative to the footwall.

Reverse

A _ fault has a vertical fault plane and shows movement parallel to the orientation o the fault.

Strike-Slip

Which type of fault was responsible for the devastation associated with the 1906 earthquake in San Francisco?

Transform

_ 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 of the following best describes the age relationship of the layers in an anticline.

Oldest on the in side of the fold, youngest on the outside

What is the term for stored-up energy released by earthquakes?

Seismic

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 he epicenter to your geologically impaired friend?

The location on the Earth’s surface directly above the point of slippage.

What is the definition of the focus?

The exact location on the fault where slippage occurs

_ 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

Which seismic wave will b released first during an earthquake?

P-waves

When going from a 5 to a 6 on the Richter Scale, what is the increase in amplitude of seismic waves?

10 times

Liquefaction will _.

Amplify the power of seismic waves

Which of the following would be the most unstable during an earthquake?

Unconsolidated sediment