History of Lisbon francophile compatriots for the brutality and depredations of the French. Meanwhile, to control access to the capital, Wellington's chief engineer, Richard Fletcher, built the defensive lines known as the Lines of Torres Vedras across the peninsula on which Lisbon sits, using Portuguese workmen. Bounded by the Atlantic Ocean on one side and the Tagus on the other, the city was reachable only by a narrow stretch of land blocked by a range of hills stretching from Sintra to Torre Vedras, which since Roman times had marked the bounds of Lisbon's territory. Conceived by Fletcher and a Portuguese major, Neves Costa,
Opening of the North Atlantic Ocean The final major phase of breakup occurred in the early Cenozoic, as Laurentia separated from Eurasia. As the two plates broke free from each other, the Atlantic Ocean continued to expand. The Iceland plume is a mantle plume under Iceland that carries hot material from the deep within Earth's mantle upwards to the crust. The rising hot material weakens the lithosphere, making the separation of plates easier. The flow of hot plume material creates volcanism under the continental lithosphere. Iceland extends across the Mid-Atlantic Ridge. The Mid-Atlantic Ridge is a divergent plate boundary, and it separates the Eurasian and North