Plate Tectonics Flashcards
types of plate boundaries
convergent boundary
divergent boundary
transform boundary
plates move toward each other
results in SUBDUCTION (one plates move under another and forced to sink in due to high gravitation potential energy into the mantle) of oceanic lithosphere
associated with the formation of volcanic arcs and the formation of mountain ranges
example: himalayas
convergent boundary
types of convergent boundary
oceanic-oceanic
continental-continental
oceanic-continental
one of the oceanic plates will go under the other, producing magma chambers that produce volcanic island chains, trenches
oceanic-oceanic
produces compressed rocks, which form mountain ranges
continental-continental
the oceanic plate will go under the continental plane that will produce magma chambers that produce volcanoes, mountain ranges such as Andes
oceanic-continental
plates move apart from each other
results in upwelling of magma
associated with seafloor spreading
example: mid-atlantic ridge
divergent boundary
plates grind against each other
no lithosphere is created nor destroyed
can be sites for earthquakes
transform boundary
hypothesis proposed by Alfred Wegener of the breaking apart of supercontinent (Pangaea) into smaller continents then drifting into their current positions
no scientific explanation for the drifting mechanism was proposed
continental drift
provides the mechanism for the continental drift hypothesis;
proposes that Earth is divided into a solid and liquid layer
plate tectonics
outer solid layer of Earth, divided into segments called plates; plates move uniformly and are deformed across their boundaries
lithosphere
weaker inner liquid layer of the Earth
asthenosphere
rapid vibration of Earth due to release of energy from rocks that were subjected to extreme pressure; happens in faults, which are associated with plate boundaries
earthquake
evidence of plate tectonics
jigsaw fit of coastlines of south america and africa
similar fossils found on continents separated by water
similar fragments of mountain belts found on continents separated by water
similar glacial deposits found on antartica, africa, south america, india and australia
sediments closer to plate boundaries have ages that are different from those of farther sediments
moving lithosphere creates several islands even if there is only one magma source (Hawaii)
island hotspots
