Benue Trough the Central African Shear Zone and for the volcanic island of St. Helena in the Atlantic ocean. Three periods of magmatic activity (volcanic action) have been identified, 147–106 Ma, 97–81 Ma and 68–49 Ma. The first is prominent in the north of the trough, and contemporary with magmatism in Brazil, probably occurring during a period of crustal extension before the Atlantic started to open. The second is found only in the south of the trough, and may belong to a period when the extension of the Atlantic had slowed down, ending with a period of compression. The third and last
Rockall Bank dispute Answer from the Irish Minister of Foreign Affairs on 14 June 1990, an agreement was reached between the British and Irish governments on delimitation of the continental shelf between the two countries and that this included a line of delimitation across the Rockall Plateau. As a result, a very extensive area under Irish jurisdiction, including part of the Rockall Trough and Plateau, is not disputed by the United Kingdom. No further negotiations were taking place in relation to the rock at the time. More recently, on 11 June 2003, the Irish Minister for Communications, Marine and Natural Resources gave a