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Plate Tectonics – Part 2. Types of Convergent Boundaries. PLATE COLLISIONS!!!!. Oceanic – Continental Convergence. 1. Collision!!! 2. Continental Crust is less dense so Oceanic crust sinks ( subducts ) into the asthenosphere. Oceanic – Continental Convergence.
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Plate Tectonics – Part 2 Types of Convergent Boundaries PLATE COLLISIONS!!!!
Oceanic – Continental Convergence • 1. Collision!!! • 2. Continental Crust is less dense so Oceanic crust sinks (subducts) into the asthenosphere.
Oceanic – Continental Convergence • 3. Subducting Ocean Plate creates a V-shaped Trench. • 4. Oceanic Plate reaches the asthenosphere and melts.
Oceanic – Continental Convergence • 5. The melted magma begins to rise through the mantle and crust. • 6. It will rise to make a volcanic eruption. • 7. Lava cools forming a continental volcanic arc.
Andes Volcanic Mountains (South America) Cascades Mountain Range (Mt. St. Helens) Oceanic – Continental Examples
Oceanic – Oceanic Boundary • 1. Collision!!! • 2. The more dense ocean plate (older) subducts into the asthenosphere.
Oceanic – Oceanic Boundary • 3. Oceanic crust melts into magma. • 4. Magma becomes buoyant and rises. • 5. This eventually forms volcanic islands in the water.
Example of Oceanic-Oceanic Boundaries ALUETIAN ISLANDS
Example of Oceanic-Oceanic Boundaries Northern Mariana Islands
Continental – Continental Boundary • 1. Collision!!! • 2. Neither plate subducts because they are both low in density.
Continental – Continental Boundary • 3. Crust is compressed and deformed, forced upward forming a mountain range.
Example: Continental- Continental Convergence • Mt. Everest! (Himalayan Mts.)