Shared Flashcard Set

Details

Earth Science
Chapter 8 - Plate Tectonics
19
Science
Not Applicable
12/03/2005

Additional Science Flashcards

 


 

Cards

Term
Wegener
Definition
hypothesis of continental drift
Term
evidence for continental drift
Definition
continents fit together
fossils match across the seas
rock types & structures match
ancient climates
Term
Pangaea
Definition
supercontinent broke into smaller pieces & drifted apart
Term
reason for rejecting Wegener
Definition
didn't provide way to move continents
Term
Harry Hess
Definition
proposed seafloor spreading
Term
evidence for seafloor spreading
Definition
bathymetry
seismology
Term
evidence for plate tectonics
Definition
polar wandering
guyots
magnetic stripes on the sea floor
Term
Vine , Matthews, and Morley
Definition
Magnetic anomalies resulted ffromt he interaction of
seafloor spreading
reversals of the earth's magnetic field
Term
driving force for plate movement
Definition
convection currents
slab-push (ridge)
slab-pull (trench)
mantle plumes
Term
divergent plate boundaries
Definition
spreading centers where new crust is created

volcanic activity basalitc

earthquakes = shallow focus

crust older further away
Term
convergent plate boundaries
Definition
correspond to subduction zones in seafloor spreading model

shallow to deep focus

magmatic arcs forming volcanic islands
Term
ocean-ocean convergent
Definition
trench

volcanoes

back-arc basin
Term
ocean-continent convergent
Definition
magmas form batholiths

heat causes regional and contact metamorphism

magma is andesitic to rhyolitic

stratovolcanoes on continental crust

melange - accretionary wedge
Term
continent-continent convergent
Definition
neither continent subducts: collision

orogenesis: crustal thickening and deformation

suture between 2 cont: melange and ophiolite
Term
hot spots
Definition
columns of hot material rising through mantle

source: core-mantle boundary
Term
subduction zones
Definition
convergent boundaries

sites where lithosphere is descending into the asthenosphre

occurs because the density of the descending lithospheric plate is greater than that of the underlying asthenosphere
Term
reasons for plate spreading
Definition
convection cells in the mantle
ridge/slab push
trench/slab pull
hot plumes
Term
paleomagnetism
Definition
natural magnetism in rock bodies

used to determine the location of the magnetic poles and the latitude of the rock at the time it became magnetized
Term
polarity reversals
Definition
earth's magnetic field has reversed itself globally
Supporting users have an ad free experience!