Chapter 31 Plate Tectonics Flashcards
Crust
2 kinds of crust. Oceanic dark fine grained material called basalt. Lighter in color less dense coarser grain called granite.
Geology
Composition and structure of Earth’s interior
Mantle
Thickest layer made of rock rich soil in silicon & oxygen. Warmer than the crust & has iron, magnesium, and calcium.
Core
Mostly made of silicate rock and minerals denser than the crust.
Density
The amount of mass an object or material has compared to its volume
Lithosphere
Shell of cool, rigid rock. Includes crust and some of earth’s mantle. Thickest below continents and thinnest below oceans.
Asthenosphere
Lies under the lithosphere. Made of mantle rock (soft and flows slowly) .
Lower mantle
Sits between the asthenosphere and outer core. Consists of strong and rigid mantle rock.
Outer core
Shell of hot, liquid metal mostly iron. Lies under the mantle and over the inner core.
Inner core
Solid sphere of hot metal mostly iron. Maximum temperature more than 7000 degrees celcius
Continental Drift
States that the world’s continents moved slowly over earth’s surface
Mid ocean ridge
An entire global system of underwater mountains
Ocean trench
Long, deep, steep troughs in the Seafloor
Seafloor spreading
The new lithosphere is created at mid ocean ridges
Magma
Warm liquid rock from earths interior
