| A | B |
|---|
| Pangaea | Supercontinent that existed 250 million years ago |
| Alfred Wegener | Scientist who developed the theory of Continental Drift |
| Theory of Continental Drift | Giant landmass called Pangaea split apart into smaller continents |
| Evidence for Continental Drift | Fossils of ferns, freshwater lizards, and land reptiles found on coastlines of Africa and S. America |
| Evidence for Continental Drift | Continents look like they fit together |
| Evidence for Continental Drift | Matching folded mountain chain and coal fields found in S. America and S. Africa |
| Evidence for Continental Drift | Glacial Rock deposits found in S. America, Africa, India, Australia, and Antarctica |
| Evidence for Continental Drift | Salts, Coal, and Limestone from coral reefs found as far north as Michigan |
| Evidence for Continental Drift | Coal deposits discovered in Antarctica |
| Increased technology, researching the Mid-Atlantic Ridge, and studying patterns of earthquakes and volcanoes | Led to the expansion of the Theory of Continental Drift into the Theory of Plate Tectonics |
| Theory of Plate Tectonics | Explains how the lithospheric plates, which carry the continents, move due to the convection currents formed in the asthenosphere |
| Lithosphere | Consists of the crust and upper mantle |
| Lithosphere | The layer which the solid, rigid, but moving plates are made of |
| Continental Crust | Made of oxygen, silicon, and aluminum and has a lower density |
| Oceanic Crust | Contains more iron, calcium, and magnesium and therefore, has a high density |
| Asthenosphere | Plastic layer in the mantle, which contains large, slow-moving convection currents, which move the tectonic plates above |
| Convection Currents | Circular flowing motion generated in liquids and gases due to differences in temperature |
| Seafloor Spreading | Process by which new seafloor forms at a divergent boundary and spreads very slowly away from the mid-ocean ridge |
| Divergent Boundary | Characteristics include: Formation of new ocean floor, occurs where two plates move apart, rift valleys, mid-ocean ridges, and earthquake activity |
| Divergent Boundary | Considered a constructive boundary because new material forms there |
| Divergent Boundary | Examples include Mid-Atlantic Ridge and East Pacific Rise |
| Convergent (Subduction) Boundary | Characteristics include: one plate plunging underneath another plate, deep sea trenches, mountain ranges or chain of volcanic islands on the overriding plate, location where old rock returns to the asthenosphere, and deep and violent earthquakes |
| Convergent (Subduction) Boundary | Considered a destructive boundary because older material is being destroyed when it returns to the mantle |
| Convergent (Subduction) Boundary | Examples include: Mariana Trench and a chain of volcanic islands, and the Peru-Chile Trench and the Andes Mountains |
| Evidence for Plate Tectonics | Belts of earthquakes and volcanoes are found along plate boundaries, which result from the movement of the plates |
| Evidence for Plate Tectonics | Age of rocks nearest a spreading center are younger and furthest from a spreading center are older |
| Evidence for Plate Tectonics | Age of rocks on opposite sides and equal distances from a spreading center are the same |
| Evidence for Plate Tectonics | Oceanic crust, which is being recycled, is much younger (180 million years) than the continental crust, which floats on top (4,000 million years) |
| Evidence for Plate Tectonics | Mineral pattern, formed by the Earth's magnetic field, is the same in rocks on opposite sides and equal distances from a spreading center |
| Evidence for Plate Tectonics | Heat flow, which is the measure of heat leaving the rocks of the lithosphere, is highest near the spreading center and lowest further away from the spreading center |
| Evidence for Plate Tectonics | The Elevation is highest near the spreading center and lowest furthest from the spreading center |
| Strike-Slip/Transform Boundary | Characteristics Include: plates slide horizontally past one another along a fault and shallow earthquakes |
| Strike-Slip/Transform Boundary | Considered a conservative boundary because no new material forms or is destroyed |
| Strike-Slip/Transform Boundary | Example includes the San Andreas Fault |
| Convergent (Collision) Boundary | Characteristics Include: two plates carrying continents move toward each other and collide, mountain ranges form, and earthquakes occur |
| Convergent (Collision) Boundary | Examples include the Himalyan Mountains, the Ural Mountains, and the Appalachian Mountains |
| Mesosphere | Strong, lower part of the mantle between the asthenosphere and the outer core |
| Outer core | Liquid layer of earth between the mantle and inner core |
| Inner core | Solid, dense center of the planet |
| Tectonic Plates | Pieces of the lithosphere that move around on top of the asthenosphere |
| Converging Boundary | Plates move together |
| Diverging Boundary | Plates move apart |
| Transform Boundary | Plates slide past one another |
| Hot rock from deep within the earth | Expands (Becomes less dense) and rises |
| Cooler rock near the surface | Condenses (Becomes more dense) and sinks |
| Ridge Push | Process by which an oceanic plate slides down the boundary between the lithosphere and asthenosphere by gravity |
| Slab Pull | Process in which the edge of the oceanic plate sinks and pulls the rest of the tectonic plate with it. |
