Activity 1. Complete the concepts based from the diagram above. (CONTINENTAL, (granite, 1. There are two basic types of LITHOSPHERE: CONTINENTAL and OCEANIC. a.. OCEANIC) lithospheric plate has a low density because it is made of relatively light-weight b. basalt) rocks. c. (CONTINENTAL, OCEANIC) lithospheric plate is denser than continental lithosphere because it is composed of heavier d. (granite, basalt) rocks. A lithospheric plate may be made up entirely of oceanic or continental lithosphere, but most are partly oceanic and partly continental. 2. Beneath the lithospheric plates, lies the a. of b. (CORE, ASTHENOSPHERE), a layer of the mantle composed (less dense, denser) semi-solid rock. Because the lithospheric plates are c.. (less dense, denser) than the asthenosphere beneath them, they are floating on d. bottom) of the asthenosphere. (top, (pressure and temperature, mass and depth) 3. Deep within the asthenosphere the a. are so high that the rock can soften and partly melt. The softened but dense rock can flow very b. (fast, slowly) Think of Silly Putty over geologic time. Where c. exist near the core/mantle boundary, slowly moving d. within the semi-solid asthenosphere. 4. Once formed, convection a. material from deeper within the c. (currents, waves) bring b. (temperature, depth) instabilities (conduction, convection) currents may form (hot, cold) (mantle, inner core) up toward the d. 5. As they rise and approach the surface, convection currents a. (diverge, converge) at the base of the lithosphere. The diverging currents exert a weak tension or "pull" on the Tension and b. (high, low) heat flow weakens the floating, solid plate, causing it to c. (surface, inside) solid plate above it. (break,