oceanic and continental crust

• oceanic crust is _-__ km thick, with a density of ___ kg/m cubed?

  5,10, 3.0
• Oceanic crust is mainly _____, containing ___ and _____?

  basaltic, silicon, magnesium
• oceanic crust is constantly ____ and is therefore ____?

  recycled, young
• older oceanic rock is found ___ ___ from the mid oceanic _____?


  further out, ridge
• a sunken valley is known as a what?

  graben