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 habitation or economic life of their own shall have no exclusive economic zone or continental shelf". In 1988, Ireland and the United Kingdom signed an EEZ boundary agreement, ignoring the rock per UNCLOS. With effect from 31 March 2014, the UK and Ireland published EEZ limits which include Rockall within the UK's EEZ. In October 2012, the "Irish Independent" published a picture of the Irish Navy ship "LÉ Róisín" sailing past Rockall conducting routine maritime security patrols, and claimed that it was exercising Ireland's sovereign rights over the rock. There have been various disasters on the neighbouring Hasselwood Rock and