Complex sentence: Two major extensional events have affected the West Antarctic Rift System, leading to the formation of a series of continuous, north-south trending basins stretching from the Transantarctic mountains out into the Ross Sea embayment.
Split into simpler sentences: Two major extensional events have affected the West Antarctic Rift System. This lead to the formation of a series of continuous, north-south trending basins stretching from the Transantarctic mountains out into the Ross Sea embayment.