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
Nankai Trough gas hydrate site The Nankai Trough, as a continuous gas hydrate research site for over more than a decade, is the first fully integrated field study and modern production test well project for offshore natural gas hydrates in the northwest Pacific Ocean. Six wells were successfully drilled to test natural gas hydrate accumulations off the southeastern coast of Japan, and to explore a conventional Tertiary structure. It gave scientists the opportunity to monitor the physical response of gas hydrate deposits and investigate marine gas hydrates in one of the most active earthquake zones on the planet. Research within the Nankai Trough is expected