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 Government declared that "The United Kingdom's fishery limits will need to be redefined based on St Kilda, since Rockall is not a valid base point for such limits under Article 121(3) of the Convention." This is the only example to date of a state voluntarily downgrading an insular feature to "a rock" and thus reducing the area of its claimed maritime zones. Rockall is within the Exclusive Economic Zone (EEZ) claimed by the United Kingdom. In 1997, the UK ratified the United Nations Convention on the Law of the Sea and thus relinquished any claim to an extension of its