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Plate boundaries. 8-3.6 Chapter 6, lesson 3 Page 198-205. Divergent boundary. Where 2 plates are moving apart Most are located along mid-ocean ridge (sea floor spreading) New crust forms b/c magma pushes up & hardens between separating plates. Convergent boundary.
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Plate boundaries 8-3.6 Chapter 6, lesson 3 Page 198-205
Divergent boundary • Where 2 plates are moving apart • Most are located along mid-ocean ridge (sea floor spreading) • New crust forms b/c magma pushes up & hardens between separating plates
Convergent boundary • Where 2 plates come together & collide • Activity depends on the types of crust that meet • More dense oceanic plate slides under less dense continental plate or another oceanic plate -subduction zone , some crust is destroyed • 2 continental plates converge, both plates buckle & push up into mountain ranges
Transform boundary • Where 2 plates slide past each other • Crust is neither created nor destroyed • Earthquakes occur frequently along this type of boundary
Changes of Landforms over Geologic Time • Plates move @ very slow rates- from about 1 to 10 cm per year • At 1 time- continents joined together in one large landmass called Pangaea • As plates continued to move & split apart, oceans were formed, landmasses collided 7 split apart until Earth’s landmasses came to be in the positions they are in now
Evidence • Evidence of these landmasses, collisions, & splits comes from fossils, landform shape, features, rock structures, & climate changes • Landmasses changes can occur at hot spots within the lithospheric plates • Hot spot- area of volcanic activity in the middle of a tectonic plate • Earth’s landmasses will continue to move & change during the geologic time of the future