1. Lesson 24 – pages 19-20

2.  To learn how constructive plate margins form.  To learn how mid-ocean ridges form.  To learn how rift valleys form.  Key Skill = Communication

3. Rising mantle rocks push crust up to forma a ridge. Currents pull crust apart. Crust faults an central b lock falls to form the rift. Magma squeezes up faults to create new crust. Process repeats.

4.  Draw a labelled sketch to describe and explain the formation of a mid-ocean ridge.

5. Continental rift valleys form where a constructive plate margin is within a continent.  The best-known example is the East African rift valley, which runs through Uganda.  The continent is pulled apart by the currents in the mantle.  This causes blocks to drop causing rift valleys and steep cliffs.

6.  Plate pulls apart.  Rock faults.  Blocks fall  Magma squeezes up faults.

7.  Draw a sketch to show the formation of a rift valley.  How did Mount Elgon form?