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 Nankai Trough gas hydrate site Nankai Methane Hydrate Site (or "Japanese Methane Hydrate R&D Program at Nankai", "Nankai Trough Methane Hydrate Site") is located in the Nankai Trough, Japan. The Nankai Trough is located beneath the Pacific Ocean off the southeast coast of Japan, and extends more than 700 km in a southwest-northward trending direction. The Nankai Trough is not only known as an active subduction and earthquake zone, but also for its large clathrate hydrate deposits occurring on the shelf and continental slope. Due to the combination of Japan’s lack of domestic fossil energy sources, along with a projected