When Pangaea split up what happened to the western edge of the North American continent? Answer choices. It collided with volcanic islands and large sections broke off into the ocean forming islands off the coast of Washington, it collided with volcanic islands forming the cascade mountain range in the region of Washington, it collided with plates deep within the Pacific Ocean creating a vast plateau in Washington, it collided with plates deep with in the Pacific Ocean driving underneath the ocean plates and forming the Pacific coast line
