Lithosphere
- Solid portion of the Earth
- Crust and upper mantle
- Crust = 3-37 miles thick
Where is crust think?
Where is it thin?
- Continents and mtn. ranges
- Ocean Floor
Geologic Cycle (Rock cycle)
Ongoing state of change in the lithosphere
Uniformitarianism
Important Why?
- The process that currently shapes the Earth have always done so in the same manner.
- Allows us to assume things happening today happened the same in history.
Continental Drift
- The idea that the continents are not stationary on Earth’s surface.
- Alfred Wegener - fossils, shape, rock sequences.
2 discoveries proved Wegener right
Paleomagnetism
Sea Floor Spreading
Paleomagnetism
The study of Earth’s
magnetic field through time
Plate Tectonics
The idea that Earth’s crust is made up of various
plates that float above the mantle (causes resistance)
Divergent Boundaries
Areas where plates move away from each other
- mid-ocean ridges - New crust created
Ex.) Middle East/Eqypt
Convergent Boundaries
Areas where plates move toward each other
- Crust is re-melted - Subduction Zone
Convergent Boundaries
- Ocean crust is more dense than continental
- Ocean crust is subducted and destroyed
- Due to its basaltic makeup
Terranes
Features “captured” by continents
-Galapagos (future)
Hot Spots
Abnormally hot areas of the mantle that are
anchored in place as the crust moves above them
Volcanism
Often matches plates (Pacific Ring of Fire)
Effusive Eruptions
Gentle, flowing lava
Ex.) Hawaii and Columbia Plateau
Explosive Eruptions
Thick, sticky lava
–Silica
–Water, gasses
Ex.) Mount Rainier and Mount St. Helen
Volcano Location
- Hot spots and divergent boundaries
- Convergent boundaries
