Download Plate Tectonics

Plate Tectonics
Tectonics - study of the origin & arrangement of the structural features of the Earth’s
surface, including folds, faults, mountain belts, continents, & earthquake belts
Continental Drift - movement of continental masses across the Earth’s surface
Sea Floor Spreading - new lithosphere material (i.e. oceanic crust & upper mantle
material) is being added along a series of mountain ranges on the ocean floor
Plate Tectonics - term used to encompass the totality of the process
Alfred Wegener - German meteorologist, considered to be the pioneer of modern continental
drift theory. In 1915, he published his theory based on a 1912 lecture:
~200 million y.a.: all the continental mass was one large continent, Pangaea
~150 million y.a.: it began to break up
~140 million y.a.: India separated
~50 million y.a.: Australia & Antarctica separated
Relative Dating - via fossils; can only tell if one assemblage is younger or older than the other
but not the actual age
Absolute Dating - via radioactive isotopes; can give the age of rocks to within 2-3% of their
actual age
Magnetic Dip
Polar Wandering
Polarity Reversal
Subduction Zone - place where one plate goes under another
Hot Spot - area of volcanic eruptions & high heat flow; it is believed that 50-120 hot spots exist
with the majority located away from plate boundaries
ex: Hawaii, Yellowstone, Iceland (near a plate boundary)