Geology Exam 2

relative age: ______ order of geological events

chronological

folds are a cause of ______ stress

compressional

there is ______ stress (push together) at reverse thrust faults

compressional

______ collision can cause metamorphism as rock at surface is pushed down deeper

continental

compression leads to _____

contraction (shortening)

contraction features are prominent at _____ boundaries

convergent

the largest earthquakes occur at ______ plate boundaries, associated with TSUNAMIS

convergent

seismic waves _____ back to surface when density increases with depth

curve

in strike-slip faults, blocks move ____

horizontally

increase of depth leads to ______ in pressure

increase

P-waves move through the ______ of the earth

interior

schist is ______ to high grade

intermediate grade

the number of earthquakes varies ______ with magnitude

inversely

types of fractures:

joints, cracks/breaks

earthquake amplitude scales are _____, meaning each unit is a factor of 10

logarithmic

L-waves (___) are _______ waves

love, surface

heat spurred by nearby _______ moves away as magma _______ which causes metamorphism

magma, cools

__________ __________ indicates the intensity of metamorphism

metamorphic grade

the higher the temp. and pressure, the higher the ______

metamorphic grade

_________ is a transformation of a ______ to another rock, for all 3 rock types

metamorphism, protolith

any type of rock can be _____

metamorphosed

metamorphism can cause change in...

mineralogy and texture

____ accumulate in fault lines

minerals

_________ is the group (assemblage) of minerals that make up a rock

minerology

normal faults lead to chairs of _____

mountains

at the s-wave shadow zone there are _____ s-waves

no

absolute age (____ age): assigns an age using ____

numerical, tools

seismic waves helped discover the earths liquid _____ core by the s-wave _____ zone and the p-wave shadow zone

outer, shadow

after gneiss, ______ melting leads to migmatite

partial

folds are also _____ deformation

plastic

earthquakes show boundaries of _____ ______

plate tectonics

even stress on all sides creates ____

pressure

there are different ______-______ paths of metamorphism

pressure-temperature

P-waves (_____) are fast and the first waves we feel

primary

_______ metamorphism means increasing pressure and temperature

prograde

rock it was before

protolith

tension causes geologic features to ____ ____

pull apart

in reverse (thrust) faults, one block is _____ up

pushed

R-waves (______) are also ______ waves

rayleigh, surface

seismic waves ______ and ______

refract, reflect

at the p-wave shadow zone, P-waves are highly ______

refracted

geologic time describes both ____ and _____ terms

relative, absolute

______ metamorphism means lowering the pressure and temperature

retrograde

contraction features include:

reverse/thrust faults, folding

earthquake magnitude can be measured by ________ scale or________ magnitude

richter, moment

the ______ _______ explains the rock transformations between ______, ______, and _______

rock cycle, igneous, metamorphic, sedimentary

P waves travel through both solid ______ and ______ but are slower in liquid

rock, liquid

s-waves (______) are slower than P-waves and also move through the _______

secondary, interior

relative age principle of original horizontality

sediments are deposited in horizontal layers

________ _______ are vibrations in the rock generated by rupture along a fault

seismic waves

earthquakes are the ______ of the ground caused by _____ waves

shaking, seismic

progressive metamorphism of shale is...

shale to slate to schist to gneiss

shear leads to _____

shear

a change in texture can be through....

size and shape of crystals in rock

shear makes geologic features _____ past each other

slide

metamorphic reactions are very _______ but are sped up when you have _____ in rock

slow, fluids

there are lots of ______ earthquakes and few _____ earthquakes

small, big

metamorphism occurs in the _____ state

solid

once an S wave hits liquid, it ____

stops

deformation results when geologic stress leads to ____

strain

______ is needed for foliation

stress

ruptures are caused by accumulation of _____

stress

_____-_____ faults occur at shear transform boundaries

strike-slip

example of contraction

subduction zones, continental collisions

a _____ is a fold shaped like a trough

syncline

compression pushes geologic features ____

together

anticlines and synclines can occur ______ and are often part of the _____ structure

together, same

_______ boundaries are responsible for significant earthquake risk (San Andreas Fault in CA)

transform

shear features are prominent at _____ boundaries

transform

these rock ______ are driven by ______ ______

transformations, plate tectonics

different ______ of P and S waves help locate earthquake _____

velocities, epicenters

in strike-slip faults, the fault plane is nearly ____

vertical

a joint is

volcanic lava flow

relative age principle of superposition

younger deposition of sediments has younger on top

a displacement is a form of _____ deformation

brittle

fractures are a form of _____ deformation

brittle

the epicenter is the point on the surface directly _____ the focus

above

the fault plane at reverse thrust faults is at an _____

angle

an ______ is a fold shaped like an arch

anticline

earthquakes are initiated by a _____ or ______ in a fault

break, shift

metamorphism occurs _____ in the earth's crust

deep

geologic stress leads to ____

deformation

different types of plate interactions at boundaries lead to _____ styles of deformation

different

faults are cracks/breaks with _____

displacement

smaller earthquakes occur at ______ boundaries

divergent

in normal faults, one block ______ down

drops

______ deformation results in squishing rather than shatterng

ductile

tension results in ______

elongation (stretching)

elongation features are prominent at _____ boundaries

extensional

in normal faults, there is ______ stress (pull apart)

extensional

folds: formerly _____ layers bent into folds

flat

circulation of _______ also causes metamorphism

fluids

fault ruptures initiate at the _______ (also known as the hypocenter_

focus

underground point on fault plain where movement starts

focus

folds are a type of ____ deformation

folds

alignment of crystals

foliation

there are _____ types of seismic waves

four

The 4 Fs of deformation are:

fractures, folds, faults, foliation

_______ is the highest grade of metamorphic rock

gneiss

metamorphism can be caused by...

heat, pressure, and fluids