1. 17.1 Notes: Earth’s Mantle & Crust Continental crust Thickness: Continental crust is thicker (30-40Km) Age: older (up to 4.4 billion yrs old) Composition: Granite, w/ basalt & diorite beneath Density: Less dense

2. Oceanic Crust Thickness: Thinner (6-11km) Age: younger (200 million yrs old) Composition: basalt gabbro Density: more dense

3. Moho (Mohorovičić discontinuity) Structure: a low pressure & temperature region, so rock becomes more rigid & slows down seismic waves.

4. Upper Mantle Structure: Thin top section w/ extreme pressures. Pressures & temperature increase with depth.

5. Lower mantle Structure: Bottom section has a higher temperature & pressure than upper mantle

6. Describe movement between lower & upper mantle: Rock isn’t quite solid here so it moves like a very thick liquid (due to convection).