gly 2010 final

Between peridotite and granite , which has a higher crystallization temperature ?

peridotite

Between basalt and granite which has greater density? why?

basalt - iron rich

Between basalt and granite , which has greater silica content ?

granite

Between basalt and granite , which is more viscous ?

granite

Between basalt and gabbro , which one is likely to have coarser mineral grains ? Why?

Gabbro- it is intrusive and has a slower cooling rate (high crystalization)

Felsic

fine -grain sediments; higher Crystallization temp

NaCl Question What type of chemical bonding holds the Na and Cl atoms together in table salt?

ionic bonds

The mineral with the chemical formula Mg Si4O10 ( OH ) 2 is ____________

sheet silicate

Which of the following minerals is a carbonate ?

calcite

What is NOT an example of silicate network ?

triple chain

Fundamental unit of silicate ions is :

SiO4

Charge on the fundamental unit of silicate ion is :

\-4

Olivine is

(Mg, Fe)2 SiO4

Albite is:

NaAlSi O8

The angles between the two cleavage planes in pyroxene ( single chain silicate ) are:

90° and 90°

In a framework silicate , of the oxygen ions of \[ SiO4 \]__________are connected to other SiO4

4

lonic bonds are formed by:

transfer of electrons

Covalent bonds are formed by:

sharing of electrons

What are the four most common elements , making up about 90 % of Earth's composition ?

iron , oxygen , silicon , magnesium

Which of the following Earth systems is ( are ) powered by internal heat ?

both the plate tectonic and geodynamo systems

What statement about convection in the mantle and the outer core is correct ?

Convection in the outer core is a million times faster than in the mantle

What is the approximate age of Earth ?

4,600,000,000 years

Which statement correctly relates density changes to Earth's features ?

Density increases from crust to mantle , and from the mantle to the core because of changes in chemical composition

what feature is NOT associated with a divergent plate boundary ?

deep - sea trenches

The oldest oceanic rocks are about _______Ma , which records about _________of Earth history

200; 4%

Which of the following phenomena is normally present at all types of plate boundaries ?

earthquakes

If there were no convergent plate boundaries , and only spreading centers at mid ocean ridges were present on Earth , what would happen to our planet ?

it would expand

Oceanic Crust

more dense

continental crust

less dense

Weathering that results in the transformation of one mineral Into a different kind of mineral is referred to as ________ weathering

chemical

Which is an example of chemical weathering ?

dissolving of limestone by rainwater

Biological sediment includes :

shells

Which assemblage of minerals would indicate the lowest weathering intensity ?

quartz, feldspar, pyroxene , amphibole

Well - rounded sediment suggests sediment has been________

transported a long distance distance

In what depositional environment would you expect to find large - scale cross - beds BEST preserved ?

eolian dunes

Well - sorted quartz sand clasts were most likely deposited:

in a beach or dune environment

The occurrence of conglomerate mudcracks, sandstone , and mudstone with asymmetrical ripples and root traces suggest a _________ environment

river and floodplain

The occurrence of limestone and fossil coral suggest a _________ environment

reef

Which rock type contains only very small ( silt and clay ) sediment grains ?

shale

Which rock type is the most likely to be composed of pieces of organisms?

limestone

Coal forms from the accumulated remains of:

plants

Foliation is produced in metamorphic rocks primarily as a result of:

directed pressure

Metamorphism occurs as the result of increased heat from

Earth's interior; magma

Which type of metamorphism is produced along convergent plate boundaries ?

regional

Which type of metamorphism is produced near magma chambers ?

contact

Which type of metamorphism is produced from meteorite impacts ?

shock

How do crystal size and foliation change with increasing intensity of metamorphism ?

Both crystal size and foliation coarseness increase

Which of the following types of foliation indicate the greatest intensity of metamorphism ?

gneiss

Which of the following types of foliation indicate the lowest intensity of metamorphism ?

slate

which is the most likely parent rock of marble ?

limestone

Which is the most likely parent rock of quartzite ?

sandstone

Which is the most likely parent rock of phyllite ?

shale

What type of forces dominates at transform plate margins ?

shearing

The angle at which a sedimentary bed is inclined from horizontal is called the :

dip

In a symmetrical syncline fold structure , the limbs of the fold dip :

toward each other

The modification of rocks by squeezing , stretching , folding , and faulting is :

deformation

A geologic cross - section shows :

a vertical slice cut through a part of the crust

Igneous and metamorphic rocks in the crystalline basement tend to be__________whereas overlying sedimentary rocks are commonly___________

hard and brittle ; soft and ductile

A region of folds cut by normal faults indicates the following sequence :

compression followed by tension

Which of the following types of deformation are observed along the San Andreas fault?

reverse faulting 

strike-slip faulting 

rifting and volcanic activity

What can a geologist learn by measuring the orientation of faults and fold structures in a particular location ?

the directions of forces causing folding and faulting

Extremely large earthquakes take place on megathrust faults found at :

continent - ocean convergent boundaries

A circular dome structure is most likely to be found at which kind of location ?

continental interior

What type of structure is a basin ?

a syncline where all beds point toward the center of a depression

If tensional tectonics are taking place in a certain location , would you expect faults to have larger dip angles in the shallow crust or the deeper crust ?

shallow crust

Why would geologists use times of mass extinctions as boundaries between eras and / or periods ?

Mass extinctions cause obvious change in fossil assemblages across time boundaries

A nonconformity is :

A gap in the geologic record bounded below by metamorphic or igneous rocks and bounded above by sedimentary rocks

Which type of unconformity has sedimentary rocks both above and below the unconformity surface ?

both an angular unconformity and a disconformity

What scientific avenue of investigation gave scientists the best estimate of the absolute age of the Earth ?

radiometric or isotopic dating

An igneous rock was formed with 20000 radioactive ( parent ) atoms but contains only 1250 radioactive ( parent ) atoms today . If the half - life for the radioactive element is 10 million years , the rock is:

40 mya

Dinosaurs lived during which era of geologic time ?

Mesozoic

Carbon - 14 is not useful for dating most rocks primarily because :

the effective dating range is much too short to be useful for most rocks

Why does most of our information on geologic history come from continental rock ?

Oceanic crust older than 200,000,000 years has been recycled by subduction

The half - life of a radioactive material depends on :

the half life is constant for any one material

The Precambrian represents about what fraction of the age of Earth ?

90%

What is the most abundant element in Earth's core ?

iron

Which statement about convection in the mantle and the outer core is correct ?

Convection in the outer core is a million times faster than in the mantle

Which statement correctly relates density changes to Earth's features ?

Density increases from crust to mantle , and from the mantle to the core because of changes in chemical composition

Which of the following features is NOT associated with a divergent plate boundary ?

deep-sea trenches

Why does the presence of fossils of the reptile mesosaurus only in South America and Africa support a previous connection between the two continents about 300 million years ago ? different fossils ) for

between Evolution would cause the development of different species ( and different fossils ) for later times , consistent with observations 

\
Mesosaurus was a freshwater organism and could not have traveled across an ocean between continents

What evidence helped give strong support for the hypothesis of seafloor spreading at mid ocean ridges ?

A. ridges frequent earthquakes located along the ridges answers 

B. a rift present along the crest of the ridges 

C. samples of very young basalt taken from the seafloor of the Atlantic Ocean

Which of the following phenomena is normally present at all types of plate boundaries ?

earthquakes

At a continent - ocean convergent boundary , the ______ plate will subduct , because it is ______

oceanic ; denser

The mineral with the chemical formula Mg3Si4O10 ( OH ) 2 is a ______ silicate

sheet

Minerals are formed

A. during the cooling of a molten rock 

B. during evaporation of water upon 

C. changes in temperature and pressures on existing mineral

The single between the two cleavage planes in \*amphibole\* is:

20 ° and 60 °

What does the isotopic age of rock measure or in other words , when does the isotopic clock start ?

The length of time since radioactive isotopes are locked into a crystallizing igneous mineral or recrystallizing metamorphic mineral

What is the geologic time scale ?

a division of Earth's history into time intervals beginning and ending at times when fossils changed significantly

At a seismograph station , what types of seismic waves arrive before the surface waves ?

Both P and S waves

What type of information can be gained by examining the first motion ( push or pull ) of P waves arriving at different seismograph stations ?

type of faulting

______ is an example of a primary hazard that can cause damage to the surrounding environment during an earthquake .

Ground shaking

The recurrence interval for a seismically active fault is the :

number of years required to accumulate the strain necessary to produce an earthquake

Why are earthquakes at depths greater than about 20 km rare in continental crust ?

At greater depths , high pressure and temperature makes crustal rock ductile so it does not rupture

Determining ______ requires measuring both amplitude of the greatest wave and distance to the epicenter using the seismograph

Richter magnitude

The distance of motion , or displacement , along a fault during an earthquake is known as :

fault slip

When scientists count earthquakes around the world and compare their magnitudes , they find that :

(a . there is an anomalous magnitude range , about 4 to 5 , where almost no events are detected)

(b . there are equal numbers of earthquakes at all magnitudes)

(c . most earthquakes have magnitudes between 4 and 6)

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None of the answers are correct

If a major earthquake takes place relatively close to you, which combination of conditions would be most dangerous under normal circumstances ?

in a valley filled with soft sediment while surface waves are passing through

Enormous, mega thrust earthquakes take place:

On thrust faults at subduction boundaries

Important potential secondary hazards associated with earthquakes include :

landslides

liquefaction 

avalanches

What triggers large , destructive tsunamis ?

motion of the sea floor during large megathrust earthquakes