Using the Atlantic Ocean as an example, describe in detail how an ocean basin is formed.

Ocean basins are formed at divergent plate boundaries where two lithospheric plates pull apart. The Atlantic Ocean basin began growing around 210 million years ago when heat from the mantle caused the asthenosphere to expand and rise. This caused the overlying lithosphere to lift and fracture, forming a rift. As the lithosphere continued to separate, magma rose to the surface and solidified, forming a new basaltic ocean floor. Over time, as the ocean basin continued to grow larger and deeper, water began to collect in the basin, eventually forming the Atlantic Ocean.