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
Island of Rockall Act 1972 Island of Rockall Act 1972 The Island of Rockall Act 1972 (c. 2) is a British Act of Parliament formally incorporating the island of Rockall into the United Kingdom to protect it from Irish and Icelandic claims. The Act as originally passed declared that the Island of Rockall was now part of the Scottish county of Inverness-shire (it is now in the Western Isles). The entire Act consists of a single effective section, which reads, "As from the date of the passing of this Act, the Island of Rockall (of which possession was formally taken in the name of Her