GEO lecture test 2

Broken into tectonic plates, Crust + upper mantle

Lithosphere

Who proposed continental drift

alfred wegner

where is EQ/seismic activity concentrated

plate boundaries

most divergent + transform boundaries are located at the

MOR

(C, D, T) san andreas fault

T

(C, D, T) btwn eurasian + indian plate

C

(C, D, T) Mid-Atlantic Ridge

D

(C, D, T). Japan

C

(C, D, T) Iceland

D

(C, D, T) Andes Mts

C

(C, D, T) fissure volcanism

D

most severe EQ activity (C, D, T)

C

_______ & ______ are the primary forces that move the plates

convection & Gravity

What layer occupies over 80% of the earths internal volume

mantle

reference line for longitude?

what direction does it measure?

Prime meridian

E-w

The hawaiian islands are ________ volcanoes, they formed over a ____ _____ deep in the mantle

shield

hot spot/mantle plume

Major tectonic process occuring at MOR/divergent boundaries

sea floor spreading

2 exs of Volcanic Island Arcs

japan & aleutian islands

The oldest oceanic crust is much ______ than any continental crust on earth

YOUNGER

(C, D, T) btwn Nazca plate & pacific plate

D

boundary at base of the crust

moho

plastic solid area in upper mantle, where tectonic plates move

asthenosphere

(C, D, T) volcanic island arcs

C

(C, D, T) himalayas

C

(C, D, T) andes mtns

C

(C, D, T). ring of fire

C

Composite volcanos. (C, D, T)

C

(C, D, T) Anatolian Fault

T

(C, D, T). Regional metamorphism, rocks are deformed

C

(C, D, T) Deep focus EQs dominate

C

List the 4 seismic waves on a seismogram in order

1. primary waves

2. secondary waves

3. surface waves

4. aftershocks

What seismic wave will not travel through liquids

what did this help us identify

Secondary waves

outer core

what was the downfall of Wegener’s theory

coudlnt explain HOW the cont. were drifting apart

Primary effect of an EQ

groundshaking

EXs of secondary EQ effects (6)

1. fire

2. destruction

3. death

4. tsunami

5. ground failure

6. liquifaction

what BASIC scale is used to measure EQ magnitude

Richter scale

what scale takes into account the amt of ground displacement along a fault + the type of ground involved for LARGE EQs

Moment Magnitude scale

2 reasons why damage was so severe in the mexico city EQ

1. one a filled in lakebed= SOFT GROUND

2. buildings not up to EQ codes bc of corruption (poor building)

Japan, Tonga islands, Aleutian islands all =

Volcanic Island Arcs

(T/F) seismic waves travel at same speed through earth

F

(T/F) ground shaking inc at sites w soft surface/soil layers

T

(T/F) The big island, Hawai’i. is the oldest island in the volcanic chain

F

its the youngest

instrument used to measure seismic waves

seismograph

print out of information from a seismograph

seismogram

huge ocean wave caused by shock to seafloor

tsunami

earth’s internal layer w/ the greatest volume

mantle

Hawaiian Islands & yellowstone formed over what tectonic feature

hot spots

serious phenomenon likely to occur during at least a moderate EQ in area underlain by landfill/soft soil

liquifaction

modern technology used to monitor the rate & direction of plate movement

GPS

what tectonic setting caused the 2004 sumatra tsunami

converging plate boundary, subducting plate got caught, snapped back into place

(C, D, T) Pacific plate meets australian plate

C

(C, D, T) iceland

D

(C, D, T) indian plate + eurasian plate

C

Pacific plate + N american plate at aleutian islands

(C, D, T)

C

what causes nearly all EQ-related deaths

collapsing buildings/structures

besides an EQ, what other events could cause a tsunami

Meteorites

volcanic erruption

submarine landslide

Southern california accounts for ____% of the nations EQ risk

50

very first national park est

yellowstone

mexico city EQ est organized _____________

search & rescue teams

equator = reference line for ____

latitude

a circular/oval UPFOLD

dome

what type of fold is the massanutten mtn

syncline

Circum-pacific EQ belt follows what volcanic zone

ring of fire

what name is given to a fold that has been OVERTURNED on its side

recumbant

Death valley + others in great basin are bounded by _____ on e side

normal

(C, D, T) btwn N american plate + pacific plate @ california

T

(C, D, T) btwn Juan de Fuca plate & N american plate

C

what is it called when a fold is dying

a plunging fold

where does most crustal deformation occur?

plate boundariesf

force applied to an area

stress

3 stages of deformation

1) elastic

2) plastic

3) failure/faulting

factors influencing the strength of a rock/how it will deform (4)

1) temp (warmer=more elastic)

2) confining pressure/depth

3) rock type (sed=weaker)

4) time

Which deformation is permanent

elastic or plastic

plastic

Folding:

what stress?

elastic of plastic?

tectonic setting

compression

plastic

convergent

large, step-like folds in otherwise horizontal sedimentary strata/layers

what usually causes them

monoclines

buried faults

causes rock layers to fracture, break into blocks, NO MOVEMENT

joints

Jointing:

tectonic setting?

stress?

ANYWHERE

ANY STRESS

significance of jointing (3)

1) mineral deposits along joint systems

2) highly jointed → hazard/risk to construction/groundwater contamination, etc

3) provides surface for weathering to occur

List the 4 eras in order

Precambrian time

Paleozoic Era

Mesozoic Era

Cenozoic Era

What era:

longest Eon, 88% of earth’s story

know the least abt it bc rocks have been recycled

Precambrian

What era:

soft, microbes, Added oxygen to atmosphere

*stromatalites/cynobacteria

Precambrian

What era:

***appalachians formed

great coal swamps formed (closer to EQ)

Shennendoah valley formed

Paleozoic

What era:

1st vertebrates-fish

1st amphibians/reptiles

1st land plants- gymnosperms (non-flowering)

**INSECTS

paleozoic

What era:

breakup of pangaea

**Rocky Mtns formed

mesozoic

What era:

Lots of REPTILES

some small mammals

1st flowering plants

AGE OF DINOSAURS

mesozoic

What era:

---

andes/himalayas forming

AGE OF MAMMALS

cenozoic

type of age-dating used to determine an order of events?

what type of rocks are best?

Relative

Sedimentary

type of age-dating using RADIOMETRIC methods to determine a NUMERICAL age

best type of rock

absolute

igneous

why are fossils important? (3)

1) help interpret geological past (climate/geography)

2) serve as time indicators

3) allow for correlation of rx from dif places (wegener)

fossilized impression

mold

fossilized filled in impression

cast

fossilized, mineral replacement, turned to stone

petrification

fossilization, carbon residue

carbonization

fossilization, any track/trail/marking/poop/gastroliths

trace fossils

conditions favoring fossil formation (2)

rapid burial to minimize decay scavenging

possession of mineralized pts (skeleton/shell) to make a mold

importance of stromatolites (2)

oldest known fossils

put oxygen into the atmosphere

what form stromatolites

cyanobacteria

evidence of stromatolites putting oxygen in atmosphere

Banded Iron formations

an unstable radioactive isotope

parent

spontaneous changes(decay) of atomic nuclei

radioactivity