THEORY OF PLATE TECTONICS CHAPTER 10 SECTION 3 PAGE By: Brielle, Rachel, and Alec

TERMS  Plate Tectonics is the belief that scientist have in which the Earth’s crust and upper mantle is broken into sections.  This was created by combing the theory of seafloor spreading and continental drift  The lithosphere are the plates that make up the crust and the upper part of the mantle.  Plates are parts of Earth’s crust that are broken into sections  The asthenosphere is the liquid section on which the plates move.  Oceanic plates are plates that lie underwater.  Continental plates are plates that are on land

WHAT ARE PLATES?  Plates are the sections of the lithosphere that move on the asthenosphere  Different boundaries can form mountain ranges, earthquakes, faults, and volcanoes  There are three different types of boundaries  A divergent- when plates move apart  A convergent- when plates collide  A transform- when plates slide past each other

TYPES OF PLATES  Oceanic Plates colliding with Continental plates can form subduction zones.  Subduction Zones are where oceanic plates sink under the continental plates creating landforms such as mountains.  Strike-Slip Faults are created at transform boundaries when two plates slide past one another without moving apart or colliding with one another  Normal Faults are formed when forces stretch the Earth’s crust  Causes blocks of crust to break and tilt or slide down the broken surfaces of crust  Rift Valleys are formed when magma gets forced up through  East African Rift Valley  Seafloor Spreading forms where oceanic plates continue to separate  Mid-Atlantic Ridge

WHAT IS THE CONVECTION CURRENT?  Scientist believe that the plates move because of the convection current in the mantle.  A convection current is a entire cycle of heating, rising, cooling, and sinking.  Causes thermal energy to move from the heat source to the other portions of the liquid  The plates of the lithosphere are then moving on the asthenosphere.

REVIEW  An oceanic and a continental plate colliding can cause a subduction zone  The current in Earth’s mantle that transfers heat in Earth’s interior is a convection current  The theory that scientist combine to develop the theory of plate tectonics was created by a seafloor spreading theory and continental drift theory  Sections that move on a plastic-like layer of the mantle is the plates