Plate Tectonics Flashcards
Folding
buckling of rocks caused when rocks are under pressure from both sides
Seismic waves
waves of energy that travel through the Earth’s crust, caused by earthquakes
Lithosphere
the rigid outer part of the earth, consisting of the crust and upper mantle.
Hydrosphere
all the waters on the earth’s surface, such as lakes and seas, and sometimes including water over the earth’s surface, such as clouds
Atmosphere
the envelope of gases surrounding the earth
Continental Drift
movement of the plates of the Earth’s crust in relation to each other
Pangaea
a super-continent that existed about 225 million years ago
Convection Currents
circular movement that occurs when warmer, less dense fluid particles rise and cooler, denser fluid particles sink
Plate tectonics
the theory concerning the movement of the continental plates
Mantle
thick layer inside the Earth, below the crust. Most of the mantle is solid rock, although the upper part is molten rock called magma
Continental Crust
the plates of the Earth’s crust that make up the land
Oceanic Crust
one of the types of crust that makes up the Earth’s outer layer. Oceanic crust is thinner than continental crust and made up of dense, heavy rocks such as basalt
Subduction
process in which two tectonic plates push against each other, and oceanic crust sinks below the less dense continental crust
Destructive plate boundary
a convergent boundary where two plates collide
Constructive plate
plate that creates new land from cooling magma
Ocean ridges
an area where the tectonic plates move apart, allowing magma from the mantle to rise, forming underwater volcanoes and creating new oceanic crust as it is cooled and solidified by sea water
Laurasia
one of the two smaller continents created when the supercontinent Pangaea broke apart about 200 million years ago
Gondwanaland
one of the two smaller continents created when the supercontinent Pangaea broke apart about 200 million years ago
Hotspots
a localised place where an activity occurs
Anticlines
folds that bend upwards
Synclines
folds that bend downwards
Fault
a break in a rock structure causing a sliding movement of the rocks along the break
Rift valleys
a sunken area where two blocks of crust have dropped down between faults
Horst
a block of the Earth’s crust, with faults on either side, that has been pushed upwards by the forces below
Slip fault
a geological feature where movement along a fault is sideways—that is, where the blocks of crust slip horizontally past each other