GEO - Chapter 1 Flashcards
What are the 4 layers of the earth from the inside out
- inner core
- outer core
- mantle
- crust
What state is the Earth’s mantle
solid
What is the crust made of
- solid rock
- split into oceanic and continental
What state is the outer core
liquid
What state is the inner core
solid
Continental drift theory:
- Pangaea - supercontinent, broke into smaller continents over millions of years
- continents constantly drifting
What are 3 major pieces of evidence to support the Pangaea theory:
- Continents could fit together
- Mountain chains and similar rock types line up on different continents
- Similar plants and animal fossils found line up
What are Convergent plate boundaries
Tectonic plates move towards each other
What are the location types of convergent plate boundaries
- Oceanic-oceanic
- oceanic-continental
- continental-continental
What does Oceanic-oceanic convergance cause
- subduction of one plate, producing oceanic trenches and underwater volcanoes
What does Oceanic-continental convergence cause
- subduction of the oceanic crust, causing trenches on oceanic crust and volcanoes on continental crust
What is Continental-continental convergence
- crust pushed up to form mountain ranges
True or false? Subduction never results in the destruction of the subducting crust.
False - Subduction always results in the destruction of the subducting crust.
What are divergent boundaries
Tectonic plates moving apart from one another
What are the types of divergent boundaries
- oceanic-oceanic
- continental-contincental
What does Oceanic–oceanic divergence cause
- mid-ocean ridge and seafloor spreading
What does continental-continental divergence cause
- rift valley and volcanoes
True or false: there are 3 types of divergence; oceanic-oceanic, oceanic-continental, and continental-continental.
False - oceanic-continental divergences don’t occur EVER
What is a transform boundary
tectonic plates that slide past each other
What are caused by a transform boundaries
- Faults, producing earthquakes
What are the 3 possible reasons for a tectonic plate to move
- convection currents
- ridge push
- slab pull
What are convection currents
- slow circular currents that drag plates horizontally,
- caused by hotter parts of the mantle that rise and then cools, dropping
What is a ridge push
- gravity pulls down on mid-ocean ridges
- pushing oceanic plates away from the divergent boundary
What is a slab pull
- plate is pulled by the weight of its cold, dense subducting section
When is crust formed
- divergent boundaries
When is crust destroyed
- convergent boundaries
What geographic features are seen when crust is formed
- mid-ocean ridges and rift valleys
What geographic features are seen when crust is destroyed
- trenches and mountain ranges
