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Unit 3 Vocab
Plate Tectonics - Destinie Roland
Term | Definition |
---|---|
Asthenosphere | top layer of the mantle |
Subduction | process by which one tectonic plate slips beneath another tectonic plate |
Seafloor spreading | the hypothesis that new ocean crust is formed at mid- ocean ridges and destroyed at deep- sea trenches; occurs in continuous cycle of magma intrusion and spreading |
Mantle convection | very slow creeping motion of Earth's solid silicate mantle caused by convection currents carrying hear from the interior to the planet's surface |
Ridge push | tectonic process associated with convection |
Slab pull | tectonic process associated with convection currents in earth's mantle that occurs as the weight of the subducting plate pulls the trailing lithosphere into a subduction zone. |
Lava | magma that flows out onto earth’s surface |
Magma | Hot fluid below or within the earth’s crust |
Tectonic Plate | Huge pieces of earth’s crust that cover its surface and fit together at their edges |
Theory of continental drift | A theory stating that earth’s continents have been joined together and have moved away from one another |
Convergent boundary | Area on earth where two or more lithospheric plates collide |
Divergent boundary | place where two of earth's tectonic plates are moving apart |
Transform boundary | place where two tectonic plates slide horizontally past each another |
Hot spot | unusually hot area in Earth's mantle where high- temperature plumes of mantle material rise toward the surface |
Epicenter | point on earth's surface directly above the focus of an earthquake |
Focus | point on the initial fault rupture where an earthquake originates that usually lies at least several kilometers beneath earth's surface |
Pangaea | ancient landmass made up of all the continents that began to break apart about 200 mya. |
Geohazard | geological state that may lead to widespread damage or risk |
Reverse Fault | two blocks of rock are forces together by compression |
Strike- slip fault | displaced mainly in a horizontal direction, parallel to the lie of the fault |
Normal fault | block above the fault has moved downward relative to the rock below |
Compression | causes rocks to push or squeeze against one another |
Tension | refers to a stress which stretches rocks in two opposite directions |
Shearing | response of a rock to deformation usually by compressive stress and forms particular textures |
Felsic | describes igneous rocks that are relatively rich in elements |
Mafic | describes a silicate mineral or igneous rock that is rich in magnesium and iron |