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 EEZ beyond the islet. The remaining issue is the status of the continental shelf rights of the surrounding ocean floor. These are the exclusive rights to exploit any resources on or under the ocean floor (oil, natural gas, etc.) and should not be confused with the EEZ, as continental shelf rights do not carry any privileges with regard to fisheries. Ownership of these rights in the Rockall area are disputed between the United Kingdom, Denmark (for the Faroe Islands), Ireland and Iceland. The Faroe Islands are an autonomous country of the Kingdom of Denmark. Since 1948 they have had self-government