What new theory did scientists develop that combined the ideas of continental drift and seafloor spreading?
(p.284) The new theory that combines the continental drift and seafloor spreading hypotheses is called the Plate Tectonics Theory. Describe the theory. 15. On what do the tectonic plates float? (p.284) Tectonic plates float on the denser, partially molten rock of the asthenosphere. 16. Look at the map on page 285. What are the three kinds of boundaries between plates? (p.285) The three main kinds of plate boundaries are divergent, convergent and transform (strike-slip) boundaries. 17. What is a boundary in which the plates are moving apart called? A boundary where two plates are moving apart is called a divergent boundary. Where are they usually located? (p.285) Most divergent boundaries are located below oceans, at the mid-ocean rifts, but there are a few located on land, where rift valleys are formed. 18. What is a boundary in which the plates are moving together called? (p.286) A plate boundary in which the two plates are coming together is called a convergent boundary. What are the
