GEOL 1 Lecture Notes - Lecture 3: South American Plate, Mantle Convection, Convergent Boundary
Document Summary
Continental lithosphere is much less dense than the mantle below and therefore neither plate subducts. How is this magma produced?- mantle fluxing. Plate motion can be directly measured using satellites, radar, asers and global positioning. Evidence of plate motion systems: measurements accurate to within 1cm, motion rates closely match those predicted using sea floor magnet. Causes of plate motion are not yet fully understood, but any proposed mechanism must. Mantle convection may be the cause or an effect of circulation set up by ridge push and/or slab-pull. The second type of boundary, by accommodating the addition of new sea floor at divergent boundaries, the destruction of old sea floor at convergent boundaries ensures the earth does not grow in size. Andes mountain range, where the nazca plate is subducting beneath the south american plate, and the cascade range of washington, oregon, and northern california. Convergent boundaries by the character of the plates that are involved: ocean-continent, ocean-ocean, and continent-continent.
