1. Navo middle school science
Unit 7 Vocabulary
Navo middle school science

2. Crust Brittle, rocky outer layer of Earth Least dense layer
Oceanic crust is more dense and thinner than continental crust

3. Mantle Layer directly below the crust Is the thick middle layer
Contains lithosphere and asthenosphere
Less dense than the core, more dense than the crust

4. Lithosphere The crust and the uppermost mantle
Rocky layer that is brittle and rigid

5. Asthenosphere Located directly below the lithosphere
The partially melted, plastic-like layer within the mantle
The asthenosphere flows very slowly

6. Outer core Part of the dense metallic center of Earth
Is a very hot liquid layer of Earth
Moves independently from the inner core
Causes magnetic field of Earth

7. Inner core Part of the dense metallic center of Earth
Is a solid ball of iron crystals
Is under so much pressure that it stays a solid
Spins a little bit faster than the rest of earth
Causes Earth’s magnetic field

8. Rock Natural, solid mixture of minerals or grains
Scientists can classify rocks based on the way the are formed, their grains, texture, composition, and color

9. Igneous rocks
Rock that is formed when molten rock (magma) reaches Earth’s surface (lava) and cools
When magma cools, it crystallizes, thus creating Igneous Rocks
Igneous rocks form in a variety of environments:
Subduction zones
Mid-oceanic ridges
Areas of volcanic activity

10. Sedimentary rocks Forms where sediment is deposited
Sediment: rock material that forms where rocks are broken down into smaller pieces or dissolved in water as rocks erode
They are commonly formed at:
Rivers and streams
Deserts and valleys
Mountain valleys

11. Metamorphic rocks
Formed when rocks are exposed to extreme temperature and pressure, such as along plate boundaries, where rocks can change to metamorphic rocks
metaMORPHic rocks CHANGE
Can form from igneous rocks, sedimentary rocks, or other metamorphic rocks

12. Rock Cycle
The series of processes that change one type of rock into another type of rock
The rock cycle NEVER STOPS

13. Plate tectonics
Theory that states that Earth’s surface is made up of rigid slabs of rock, or plates, that move with respect to each other
Alfred Wegener
Provides an explanation for earthquakes, volcanoes, mountains, etc.

14. Earth’s Tectonic Plates

15. Divergent plate boundaries
Forms when two plates separate
Mid-ocean ridges are located along divergent boundaries
SEAFLOOR SPREADING occurs, causing new crust to form
Can also exist in the middle of a continent, causing RIFT VALLEYS to form

16. Transform Plate boundaries
Forms where two plates slide past each other
San Andreas Fault in California
As plates slide, they can get stuck and stop moving, causing force and stress to build up, until finally the plates move, causing an EARTHQUAKE

17. Convergent plate boundaries
Form when two plates collide, the denser plate sinks below the other plate in a process called SUBDUCTION
When oceanic plates collide with continental plates, the denser oceanic plate subducts under the edge of the continent, creating a DEEP OCEAN TRENCH and a line of VOLCANOES
When 2 oceanic plates collide, the older and denser oceanic plate subducts beneath the younger plate, causing a DEEP OCEAN TRENCH and a line of VOLCANOES
When two continental plates collide, neither plate is subducted, and mountains form from uplifted rock

18. Convergent plate boundaries