• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/51

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

51 Cards in this Set

  • Front
  • Back
who wrote the hypothesis called continental drift, and what did it challenge?
alfred wegener; the long held assumption that the continents and ocean basins had fixed geographic positions
what did wegener suggest? what was it called?
that a single supercontinent consisting of all earths landmasses once existed; pangaea
evidence of wegener's supercontinent hypothesis
fossils in rocks from both s.america and africa; continental drift was evident
glacier movement
similar rocks and mountains on both sides of the atlantic
one of the main objections to wegeners supercontinent hypothesis
his inability to identify a credible mechanism for continental drift
who came up with a credible mechanism for contintental drift?
tuzo wilson; 1969
earths layers are what
crust > upper mantle > lower mantle > outer core > inner core
what is the contintental crust made of
granitic-andesitic
what is the oceanic crust made of
basalt
the aesthenosphere is apart of what earth layer
upper mantle
in a convergent boundary, the lithosphere is subducted into the (c+o)
aesthenosphere
what makes up the lithosphere
earths crust and the upper most/coolest part of mantle; strong layer
Earths hotter, weaker region in the mantle that lies below the lithosphere
aesthenosphere
earths outer shell is effectively detached from the aesthenosphere and allows the layers to move independenly, is because....
pressures/temps in the upper aesthenosphere are such that rocks at this depth (100-200 km) are very near their melting point, and flow; where as the lithosphere tends to respong to forces by bending or breaking, but not flowing
type of boundaries
divergent
convergent
transform
divergent boundaries have what type of magma come up from the spreading center, and what type of earthquakes are formed
basalt magma; shallow, focus is shallow in the earth
give an example of a divergent boundary
mid atlantic ridge
examples of divergent boundaries on land
east african rift
iceland
where is the rift valley
place between spreading plates during a divergent boundary
a trench develops during what
subduction zone with oceanic lithospheres subducting
O + O subduction zones produce whar type of magma, there for form what type of volcanoes
felsic to intermediate, composite cones
the aleutian islands in alaska are an example of what type of boundary
o + o subduction
what are formed as a result of o + o subduction
volcanic island arcs
what forms from a o+ c subduction
continental volcanic arcs
o + c subduction zones create what type of magma and volcanoes
felsic-intermediate; composite
name some c + c subduction characteristics
start off as o + c
produces extreme deformation of rocks, metamorphism and faulting
name some characteristics of convergent boundaries
are of earthquakes, volcanoes and other igneous activity
viscous magma
composite cones; high silica content magma+violent eruptions
plutons form when magma doesnt reach surface
area of mountain building
crust melts parially or fully
what can form if magma does not reach surface during both an o + o, and o + c subduction
pluton (granite or diorite)
magma that does reach the surface during an o + o and o + c subduction, will be what
rhyolite or andesite
example of o + c subduction
andes mt, cascade range in WA and oregon
c + c subduction can produce
mountain ranges
either volcanic or continental volcanic arc
composite volcanoes if present
example of c + c subduction
himalayas
divergent boundaries mostly occur where
under oceans
during a divergent boundary, crust being older as one goes away from the ridge...t or f
true
low viscous magma; less violent volcanism
divergent boundary
horizontal movement between plates; new crust is not created or destroyed
transform boundary
allows for spreading to occur along divergent and convergent boundaries
transform boundary
generally no volcanism in what type of boundary
transform
earthquakes can occur from a transform boundary...t or f
true
example of a transform boundary
san andreas fault
is hot spot volcanism associated with a plate boundary?
no
hot spot volcanism can occur where
on either contintent or in ocean
characteristics of hot spot volcanism
mantle plume comes up through crust
stay stationary as crust moves over it
examples of hot spot volcanism
yellowstone
hawaii
proof that plates are moving
hotspots
thickeness of sediments-away from spreading center
ocean drilling
magnetic reversal
polar wandering
does not occur at a boundary, accumulation of sediments, depositor of flat lying undisturbed sediments
passive margin
occurs during the transition of oceanic to continental crust, on top of oceanic crust
passive margin
no tectonic activity, flat lying
passive margin
deformed, sedimentary and igneous ex (basalt) folding and faulting
accretionary wedge
occurs at all subduction zones, in between 2 plates as one plate subducts
accretionary wedge
earthquakes may happen at this boundary, but no volcanism
transform fault
all subduction zones have what
trenches
accretionary wedge
granitic - andesitic magma
composite volcanoes