Lava flow

• It cannot be the outer part, which is definitely solid. Scientists call the outer part od the earth as crust
• Below the relatively thin crust is mantle
• The uppermost part of the mantle has similar properties as the crust. Both are solid. The two together constitute the lithmosphere
• Beneath the lithmosphere, where temperatures are much higher due to the great presure from the upper layers, the rocks are somewhat melted. This portion of the mantle, called asthenosphere
• Divergent Boundary- two neighbouring tectonic plates may move away from each other. The place where the two plates are pulled apart
• Convergent plate boundary - Two neighbouring plates may move toward each other and collide
• Thus, the oceanic plate, which is denser than the continental plate, dives under the latter, forming a trench