Plate Tectonics Test Flashcards
Name the theory that explains why and how continents move.
plate tectonics
Layers of the earth
inner core
outer core
mesosphere
asthenosphere
lithosphere
What layer of earth forms tectonic plates?
lithosphere
What layer of earth is elastic, much like putty?
asthenosphere
Which layer of Earth causes the motion of the plates through convection cells of magma?
asthenosphere
Which layer of Earth is made of continental and oceanic crust?
lithosphere
Which layer of Earth generates the Earth’s magnetism?
inner/outer core
what is the main difference between oceanic crust and continental crust?
Continental crust is older and oceanic crust is younger
Name and describe the record of reverse and normal polarity in the ocean crust.
Normal polarity-north
reverse polarity-south
paleomagnetism-ancient magnetism, magnetic reversal recorded in ocean floor rocks
How does the age of oceanic rock that is closer to the mid-ocean ridge compare to the oceanic rock that is further away from the ridge?
Oceanic crust at mid-ocean ridges is the youngest rock and the crust near continents are the oldest rock.
Divergent Boundary
-plates moving away from each other
-forms a ridge or rift at the boundary
-creates new crust
Convergent continent/continent boundary
-plates are moving toward each other
-forms mountains(no subduction+no volcanoes)
-crust shortens or deforms
Transform Boundary
-plates sliding past each other
-deforms crust due to friction
-can create other small fractures(faults)
-results in earthquakes
Convergent ocean/continent boundary
-plates moving toward each other
-subduction zone-oceanic crust pushed below continetal
-forms a trench in the ocean and volcanoes on the continent
-destroys crust(melting)
Convergent ocean/ocean boundary
-plates moving toward each other
-subduction zone
-forms a trench and volcanic island arc in the ocean
-destroys crust(melting)
Explain the formation of the Himalayan Mountains
Convergent boundary between continent and continent crust(India colliding with Asia)
Explain the formation of Mt. St. Helens
convergent boundary between ocean and continent plates
Explain the formation of the Hawaii Islands
created by a hot spot
List the boundaries that can result in a volcanic eruption
Every boundary except transform
Explain what determines the type of eruption a volcano will have.
Determined by how easily gases can escape from magma
Fluid magma=easy escape=mellow eruption
Thick magma=difficult escape=violent eruption
Dike
magma cuts across rock layers
Sill
magma squeezed between rock layers
Laccolith
forms like a still but created a dome, the overlying rock is bent upward
Batholith
largest intrusion, no true shape, cuts through rock layers and often forms the core of mountains
Explain what occurs along the Pacific Ring of Fire
The ring of fire has all three boundaries(except transform)
List the plates that can result in a earthquake
Any plate boundary can result in a earthquake
Describe the elastic rebound
rocks sping back to original form following years of displacement by plate motion
-released build of strain
-earthquakes is felt during elastic rebound
List the plate boundaries that can result in mountain building
continent/continent plate boundary
Anticline
arch shaped, upward ben in rock, oldest rock in the middle of two limbs
syncline
basin-shaped, downward bend in rock, youngest rock in the middle of two limbs
monocline
step like fold, one limb
Transform/strike-slip fault
faults that break horizontally due to shearing
Normal fault
faults that break vertically due to extension
Reverse Fault
faults that break vertically due to compression
Volcanic Mountains
form along plate boundaries and hot spots due to volcanic activity
-active, dormant, extinct
Dome Mountains
broad up warping of rock, nearly circular, older rock exposed in the center, formed from laccoliths/faulting
Folded Mountains
formed from folding due to compression of the lithosphere, can also include faulting, metamorphism and intrusive igneous activity
