STRUCTURE AND MOTION TECTONIC PLATES AND PLATE BOUNDARIES

TECTONIC PLATES

TECTONIC PLATES cont. the lithosphere is broken into 10 major plates which include: the lithosphere is broken into 10 major plates which include: - north american plate- eurasian plate - south american plate- african plate - nazca plate- indian plate - caribbean plate- australian plate - antarctic plate- cocos plate

PLATE BOUNDARIES - TYPES Convergent a region where plates are pushing together a region where plates are pushing together folding and bending occur; crust is often destroyed folding and bending occur; crust is often destroyed possible results: island arcs, mountain ranges, trenches possible results: island arcs, mountain ranges, trenches  

PLATE BOUNDARIES - TYPES cont. Divergent a region where plates are moving apart a region where plates are moving apart new crust is created new crust is created possible results: new ocean floor, rift valleys possible results: new ocean floor, rift valleys  

PLATE BOUNDARIES - TYPES cont. Transform where crustal plates sheer laterally past one another where crustal plates sheer laterally past one another not marked by spectacular surface features not marked by spectacular surface features  

PLATE BOUNDARIES Subduction Zones an area at which a lithospheric plate is descending into the asthenosphere an area at which a lithospheric plate is descending into the asthenosphere Seafloor Spreading a theory that new ocean crust forms at spreading center (divergent plate boundaries) a theory that new ocean crust forms at spreading center (divergent plate boundaries) Convection Current a single, closed flow of rising warm material and falling cool material a single, closed flow of rising warm material and falling cool material