| A | B |
|---|
| Plate Tectonics | unifying theory of geology |
| Three types of plate boundaries | Convergent, divergent, and transform/strike-slip |
| 7 major plates | Eurasian, Indian-Australian, Antarctic, North Am, South Am, Pacific, African |
| PANGEA | super continent, "all land" (Alfred Wegner) |
| Gondwanaland | Southern part of PANGEA |
| Laurasia | Northern part of PANGEA |
| Continental Drift | Alfred Wegner proposed that the continents plowed through the oceanic crust or slid over top |
| Magnetism | as magma cools the iron minerals align with the magnetic field of the earth |
| Paleo-Magnetism | indicated that the poles have "apparently" wandered about |
| Led to Theory of Sea Floor Spreading | mid-atlantic ridge discovered along with other major ridge complexes |
| Plate Tectonic Theory | plates of rigid lithosphere (oceanic and contint) move from the energy of heat transfer below |
| Divergent Boundaries | where plates move away from each other AKA spreading centers of Rift Zones. both Cont and Oceanic |
| Geologic Features at Divergent Boundaries | shallow earthquakes, rising magma, volcanoes |
| Convergent Boundaries | plates collide; diff plates means diff types of collisions, density diff importnat |
| Subduction Zone | occurs in a convergent boundary when ocean and contl plates collide. |
| Subduction Zone | long narrow belts where lithosphere is pulled or pushed into the mantle and is melted |
| Continent Collision | results in massive uplift; Himalayas |
| Geologic Features at Convergent Boundaries | deep earthquakes, volcanoes, massive uplift |
| Oceanic-Oceanic convergent boundaries | subducting plate bends downward forming an oceanic trench. Volcanic island arc forms on the overlying plate |
| Continental-Continenal convergent boundaries | Low density continental crust is not subducted, but may partially underlie the other contl plate. Mntn ranges formed in interior; all rock types are found; seismically active |
| Oceanic-Continental convergent boundaries | the denser oceanic plate is subducted under contl plate; A subduction complex forms on cont side of trench; partial melting of the descending ocean plate forms an andesitic volcano mountain range |
| Transform Boundaries | plates slide past each other; San Andreas; earthquakes very common; no volcanoes |
| Transform Faults | mark fractures in the crust where plates slide laterally past each other; change one type of motion to another |
| San Andreas Fault | example of a transform boundary that separates the Pacific plate from the N. Am plate |
| Mantle Convection | heat rises in the mantle creating convection currents; plates may simply slide downhill form high created by rising magma; comb of many things pulled by forces at subduction zones |
| Rate | absolute dates of magnetic anomalies and distance traveled from ridge |
| Hot spot | used as fixed reference point to determine absolute motion |
| Metallic Minerals | gold, copper, lead, silver, tin, zinc |
| Orogeny | occur when oceanic crust is subducted beneath another oceanic plate |
| Himalayas | continental-continental boundary |
| Ductile deformation | when rocks bend of flow, ex: Clay |
| Brittle deformation | when a rock breaks |
