Chapter 4 Flashcards
What are the compositional layers?
Core, mantle, and crust
What are the functional layers?
The lithosphere (crust and upper mantle)
And the asthenosphere (lower mantle/rest of the mantle)
What is the evidence that Wegener used for his continental drift hypothesis?
- Fit of South America and Africa.
- Fossils match across the seas.
- Rock types and mountain ranges match
- Glacial evidence.
Why was Wegener’s continental drift hypothesis abandoned?
Because there was no mechanism to explain it
What do plate tectonics state?
That the Earth is divided into several geological plates(pieces of the lithosphere) that are moving relative to each other
True or false. Tectonic plates move fast.
False. Tectonic plates move slowly.
Definition of the lithosphere
- The crust and upper mantle
- Is more rigid/solid, also breaks more easily
Definition of the asthenosphere
- the lower part of the mantle, exists beneath the lithosphere
- Hotter and weaker than the lithosphere, which means it can move
- Movement in the asthenosphere allows for movement of the lithosphere that is above it
What are plate boundaries?
- all major interactions among plates occur along their boundaries (edges of plates)
- these edges of plates are called active margins
What is an example of an active margin? (where the plates are actively moving)
Western coast of North and South America
What is the definition of passive margin?
The areas where no movement or tectonic activity is occurring (ex: the eastern coast of north and South America)
What are the types of plate boundaries?
- Divergent plate boundaries.
- Convergent plate boundaries.
- Transform plate boundaries.
What is the definition of a divergent plate boundary?
Plate to move away from each other, one plate splits, apart into two plates, new lithosphere is created, can be oceanic or continental
What is the definition of convergent plate boundaries?
Plates move toward each other, two plates collide with each other, lithosphere is destroyed, three types based on the type of lithosphere.
What is the definition of transform plate boundaries?
Plates move, horizontal past each other, two plates, move horizontally, nothing created or destroyed.
What are two types of divergent plate boundaries?
- Oceanic divergent boundaries. (also known as seafloor spreading)
- Continental divergent boundaries. (also called Continental rifts)
What are the convergent plate boundaries?
- ocean-continent convergent plate boundaries
- Ocean-ocean convergent plate boundaries.
- Continent-continent convergent plate boundaries.
What is an example of continent/continent convergent plate boundaries?
The Himalayan mountains (this process causes really tall mountains, so a hint is that Mount Everest is in the Himalayan mountains)
What is a process that takes place in ocean/continent convergent plain boundaries?
Subduction
What is the definition of subduction?
Oceanic lithosphere sinks into the asthenosphere
What is an example of ocean/continent convergent plate boundaries
Andes mountains and Cascade mountains
What is an example of ocean/ocean convergent plate boundaries
Japan
What is an example of continent-continent convergent plate boundaries?
The Himalayan mountains
What is a transform plate boundary?
It’s when two plates slide horizontally past each other, no new crust is created or destroyed, it creates earthquakes.
What is an example of transform boundaries?
The mid Atlantic Ridge
What is a way that we test plate tectonics?
Ocean drilling
What is a hotspot?
Caused by rising plumes of mantle material in the middle of a plate.
True or false; a hotspot can be oceanic or continental.
True
What is an example of a hotspot?
- The Hawaiian Islands (oceanic)
-Yellowstone (continental)
