GY111 Earth Materials By David T Allison Ph D Office 344 LSCB Scientific Method Hypothesis An idea about how the natural world works Theory A model for how the natural world works that is supported by a large body of evidence and the majority of the scientific community Law A model for how the natural world works that can be expressed in mathematical terms Earth s Compositional Layering Crust thin silicate material Mantle thick layer of silicate material Core metallic Fe Ni S alloy Earth s Composition Earth s Core Knowledge of this layer is obtained indirectly from meteorites and geophysical evidence Earth s Crust Earth s Compositional Layering Summary Depth Thick Layer 7 50km Crust 650km Upper mantle 700km Basalt 3 0 Granite 2 7 Peridotite 3 3 2200km Lower mantle Garnet Peridotite 3 5 5 5 2200km Outer core Ni Fe S Alloy 10 12 1300km Inner core 2900km 5100km 6400km Ni Fe Alloy 13 Earth s Mechanical Seismic Layering Depth Thick 70 150km 550km Layer Brittle Lithosphere Asthenosphere 700km Ductile 2200km Mesosphere Brittle 2200km Outer core Liquid very ductile 1300km Inner core 2900km 5100km 6400km Brittle Earth s Energy Source of internal heat energy is radioactive decay Geologic Time
View Full Document
Unlocking...