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Plate Tectonics
Plate Tectonics Vocab
Term | Definition |
---|---|
Section 1. | |
Crust | The outermost layer of the Earth. |
Mantle | The layer of Earth between the crust and the core. |
Core | The layer of the Earth that extends from below the mantle to the center of the Earth. |
Lithosphere | The solid, outer layer of the Earth that consists of the crust and the rigid upper part of the mantle |
Asthenosphere | The soft layer of the mantle on which the tectonic plates move. |
Mesosphere | The strong, lower part of the mantle between the asthenosphere and the outer core |
Tectonic plate | Pieces of the lithosphere that move around on top of the asthenosphere. |
Section 2. | |
Continental Drift | The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations. |
Sea-floor Spreading | The process by which new oceanic lithosphere forms as magma rises towards the surface and solidifies. |
Section 3. | |
Plate Tectonics | The theory that explains how large pieces of the Earth's outermost layer, called tectonic plates, move and change shape. |
Convergent Boundary | The boundary formed by the collision of two lithospheric plates. |
Divergent Boundary | The boundary between two tectonic plates that are moving away from each other. |
Transform Boundary | The Boundary between tectonic plates that are sliding past each other horizontally. |
Section 4. | |
Compression | Stress that occurs when forces act to squeeze an object. |
Tension | Stress that occurs when forces act to stretch an object. |
Folding. | The bending of rock layers due to stress. |
Fault | A break in a body of rock along which one block slides relative to another. |
Uplift | The rising of regions of the Earth's crust to lower elevations. |
Subsidence | The sinking of regions of the Earth's crust to lower elevations. |
Normal Fault | When rocks are pulled apart because of tension, normal faults are formed. |
Reverse Fault | When rock are pushed together by compression, reverse faults often form. |
Strike-Slip Fault | When rocks are moved horizontally by opposing forces, strike-slip faults often form. |
Folded Mountains | When rock layers are squeezed together and pushed upward. |
Volcanic Mountains | When the rock that is melted in subduction zones forms magma, which rises to the Earth's surface and erupts to form volcanic mountains. |
Rift Zone | A set of deep cracks that forms between two tectonic plates that are pulling away from each other. |