Four Main Layers Inner core Outer core Mantle Crust
Crust Thinnest Layer Two types of crust : Oceanic: made mostly igneous rock and Basalt. Found under ocean, thin Continental: made mostly of granite. Found under continents, thick
Mantle Located abovethe outer core Below the crust is where the mantle starts Largest Layer 80% of Earth’s volume & 68% of Earth’s mass Composed of iron Density, Temperature, And pressure increases the deeper you go into the mantle Lithosphere :upper, solid part of mantle Asthenosphere: under lithosphere, solid rock flows very slowly
Outer Core Surrounds inner core Temp. : 2200c-5000c Iron and Nickel, Liquid
Inner Core Solid, iron and nickel Temp. can reach to 5000c Solid, because of the pressure put on the core Solid core is the source of Earth’s magnetic field
Alfred Wegener First proposed the theory of continental Drift Continental Drift was his theory that continents were joined together then drifted apart Named Pangaea a supercontinent Theory was rejected because he couldn’t explain which force pushes or pull continents Found pieces of evidence: Geologic Climate Fossil 1940s: Technology was developed
Climate evidence in the changing climates during the past.
Geologic evidence in layers of rocks across continents.
Fossil Evidence of fossils are found in certain places
Fossil Remains or physical evidence of an organism preserved by geological processes Preserved in sedimentary rock Sediment slows down decay Bones and shells are resistant to decay, more commonly preserved tissue
Examples Fossils in rock Fossils in Amber Petrification Fossils in asphalt Frozen fossil Trace Fossil Mold Cast Index Fossil