Terms in this set (49)
a hypothesis proposed by Alfred Wegener stating a supercontinent broke up into smaller continents
part of a single landmass
three pieces of evidence
fossils, rock formation, climate
long, undersea mountain chain with a steep, narrow valley
a crack in the center of the ridge
process by which new oceanic lithosphere forms when magma rises to earths surface at mid ocean ridges and solidifies
the study of the magnetic properties of rock
all rocks with magnetic fields pointing north
all rocks with magnetic fields pointing south
geomagnetic reversal time scale
pattern of alternating normal and reverse polarity in the rocks
theory explaining why the continents move and explains the formation of the earth
earths crust and rigid, upper part of mantle form this
several blocks that ride on the asthenosphere
dense and is made of rock that is rich in iron and magnesium
layer of igneous, sedimentary, metamorphic rock
less rigid layer below the lithosphere
two plates move away from each other
under sea mountain anges through the center of valleys
a crack in the center of a ridge
plate boundaries that form when 2 plates collide
deep ocean trench
deeo deoression in the ocean
chain of volcanic islands
boundary at which two plates slide past each other
transform boundary where ridge segments connect
movement of heated material due to density differences
created by cooler denser water sinking and warm rising to surface
a force exerted on the rest of the plate when cooling rock slides down slope of ridge
force exerted by sinking plates
process by which a continent breaks apart
piece of lithosphere that has a unique geologic history
process in which terrane becomes part of a continent
small coral islands
large masses of continents
process by which supercontinents form and break apart over time
super continent that formed 300 million years ago
single, large ocean surrounding pangaea
What factor is most important when determining the type of boundary that forms when 2 plates collide?
the density of each plate
What replaces rock as it moves away?
what was a weakness of wegeners proposals of continental drift?
a lack if proven mechanisms
What describes a specific type of continental growth?
terranes become part o a continent
Modern climates results from...
past movements of tectonic plates
What best describes magma formation at a divergent boundary?
magma rises at the two plates pulling apart
Earthquakes occur along this fault because...
the plates slide against each other
What best describes the supercontinent cycle that resulted in the continents?
What is not true about magnetic reversals?
they are rarely used to create a time scale
What surface features are often found at these places?
What boundary is found at South Africa and African plate?
What modern continents formed from Gondwanaland?
Africa, South American, Antarctica, Australia, and India. AAASI