1. Our Changing Earth: Part I

2. Fun Earth Facts Highest mtn: Mt. Everest 8,848m
Lowest point: Dead Sea m bsl
Longest river: Nile ,690km
Largest desert: Sahara 9,000,000 km sq.

3. 3 Types of Rocks
Sedimentary: Rocks made of sediments (soil, sand, other rocks)

4. Metamorphic Rocks – Rocks made of existing rock, heat, and pressure.

5. Igneous Rocks- Rocks formed from lava or molten rocks from volcanoes.

6. Minerals- they are the building blocks of rocks
Minerals- they are the building blocks of rocks. They are composed of one substance instead of different substances.

7. Geologic Time Scale
Definition: Chart used to describe the earth’s history through time
The time periods of the earth are divided into 4 main eras:
* Precambrian: largest era
* Paleozoic
* Mesozoic
* Cenozoic

8. Putting the Pieces Together: Part II
Wegener: meteorologist who theorized that the continents were once joined together in a single continent
Pangaea: name given to the “supercontinent” described by Wegner

9. Putting the Pieces Together (cont.)
Theory of continental drift: Wegner’s theory that continents known today were once joined together as one
*Based on : fossil evidence, shapes of cont. fitting
together, and study of climates
Plate: large masses of the earth’s crust moving in various directions—they “ride” on the mantle
Plate tectonics: the theory of how the continents move, based on Wegner’s theory of continental drift

10. The Layers of the Earth Part III
1. Crust: the thin, rocky, outer portion of the earth’s surface
2. Mantle: composed of 2 layers
a. Lithosphere: where plates are
b. Asthenosphere: slushy layer
3. Core: solid, inner layer (almost pure iron)

11. Moving Plates: Part IV
*Currents in the mantle that move the plates are caused by heat
Plates can move in one of 3 ways:
1. Converge/Collide: approach each other/hit
* when they collide, they form:
a. Trench (deep valley) where old crust is re-cycled

12. Moving Plates: Part IV b. Volcanoes c. mountains
2. Separate: move away from each other
*causes deep cracks called rifts to form
ex. mid-ocean ridge & Great Rift
Valley

13. Moving Plates cont. *sea-floor spreading: a process during
which new ocean crust is formed at mid-
ocean ridges (large mountains on ocean
floor where new crust is formed)
*On the ocean floor at the spreading center, new crust is formed
Slide past each other
*faults form like the San Andreas Fault
*earthquakes are common along these
plate boundaries