Tectonic Plates – Flashcards
33 test answers
Unlock all answers in this set
Unlock answers 33question
Pangaea
answer
Greek word meaning "all the earth."
Unlock the answer
question
Wegener's Proof (What he used as)
answer
Rocks, fossils, and climatic data.
Unlock the answer
question
Fossils (Wegener's specimens)
answer
Kannemeyerid, Labrinthodont, Mesosaurus, Glossopteris, etc.
Unlock the answer
question
Ancient Climatic Evidence (Example)
answer
Coal deposits in Antarctica, and glacial deposits in Africa, India, Australia, and South America.
Unlock the answer
question
Magnetometer
answer
A device used to map the ocean floor that detects small changes in magnetic fields.
Unlock the answer
question
Paleomagnetism
answer
Study of Earth's magnetic record using data gathered from iron-bearing minerals in rocks that have recorded the orientation of Earth's magnetic field at the time of their formation.
Unlock the answer
question
Magnetic Reversal
answer
A change in Earth's magnetic field over geologic time, recorded in ocean-floor rocks and continental basalt flows.
Unlock the answer
question
Isochron
answer
Line on a map that connects points of the same age.
Unlock the answer
question
Seafloor Spreading
answer
Hess's theory that new ocean crust is formed at mid-ocean ranges and destroyed at deep-sea trenches. It occurs in a continuous cycle of magma intrusion and spreading.
Unlock the answer
question
Helpful Technology (Seafloor Spreading)
answer
-Sonar and other echo-sounding methods -Magnetometer
Unlock the answer
question
Ocean Ridges
answer
Vast, underwater mountain changes where earthquakes occur. Their size has triggered much discussion.
Unlock the answer
question
Deep-Sea Trenches
answer
Narrow, elongated depressions in the seafloor with very steep sides.
Unlock the answer
question
Mariana Trench
answer
The deepest chasm, 11km+ deep.
Unlock the answer
question
Two Major Discoveries From Rock & Sediment Analyses
answer
1. The ages of rocks vary in different ways, and their changes are predictable. 2. The thickness of ocean-floor sediment is less that expected.
Unlock the answer
question
The Geomagnetic Time Scale
answer
A polarity time scale.
Unlock the answer
question
Normal Polarity (+)
answer
A magnetic field that has the same orientation as Earth's present field.
Unlock the answer
question
Reversed Polarity (-)
answer
A magnetic field that doesn't have the same orientation as Earth's present field.
Unlock the answer
question
Continental Basalt Flows
answer
Used to construct the geomagnetic time scale.
Unlock the answer
question
Epochs
answer
Long term changes in Earth's magnetic fields, four of which have occurred in the past.
Unlock the answer
question
Events
answer
Short term changes in the Earth's magnetic fields.
Unlock the answer
question
Theory Of Plate Tectonics
answer
States that Earth's crust and upper mantle are broken into plates, which are huge rock slabs that move in different directions and at different rates over the Earth's surface.
Unlock the answer
question
Divergent Boundary
answer
A place where two of Earth's tectonic plates are moving apart; is associated with volcanism, earthquakes, and high heat flow; found on the seafloor.
Unlock the answer
question
Rift Valley
answer
Long, narrow depression that forms when continental crust begins to separate at a divergent boundary.
Unlock the answer
question
Convergent Boundary
answer
A place where two of Earth's tectonic plates are moving towards each other; is associated with trenches, islands ark, and folding mountains.
Unlock the answer
question
Subduction
answer
Process by which one tectonic plate slips beneath another tectonic plate.
Unlock the answer
question
Transform Boundary
answer
A place where two tectonic plates slide horizontally past each other that is characterized by long faults and shallow earthquakes.
Unlock the answer
question
Convergent Boundary Types/Tectonic Boundaries
answer
1. Oceanic-Oceanic: Oceanic crust converging with oceanic crust; a form of subduction. 2. Oceanic-Continental: Oceanic crust converging with continental plates, or vice versa. 3. Continental-Continental: Continental crust converging/colliding with continental crust.
Unlock the answer
question
Ridge Push
answer
Tectonic process associated with convection currents in Earth's mantle that occurs when the weight of an elevated ridge pushes an oceanic plate toward a subduction zone. A cause of plate motions.
Unlock the answer
question
Slab Pull
answer
Tectonic process associated with convection currents in Earth's mantle that occurs as the weight of subducting plate pulls the trailing lithosphere into a subduction zone. A cause of plate motions.
Unlock the answer
