6-616: The Atlantis Massif is a prominent undersea massif in the North Atlantic Ocean . It is a dome-shaped region approximately 10 miles (16 km) across and rising about 14,000 feet (4,267 m) from the sea floor. It is located at approximately 30°8′N latitude 42°8′W longitude; just east of the intersection of the Mid-Atlantic Ridge with the Atlantis Transform Fault . The highest point of
12-416: A tectonic plate and is considered the fourth-largest driving force in geomorphology . The word "massif" originates from French (in which the word also means "massive"), where it is used to refer to a large mountain mass or compact group of connected mountains forming an independent portion of a range. The Face on Mars is an example of an extraterrestrial massif. Massifs may also form underwater, as with
18-424: A massif is frequently used to denote the main mass of an individual mountain. As a purely scientific term in geology , however, a "massif" is separately and more specifically defined as a section of a planet's crust that is demarcated by faults or flexures . In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole. A massif is a smaller structural unit than
24-418: Is usually found in the mantle . The central dome is corrugated and striated in a way that is representative of an exposed ultramafic oceanic core complex . An expedition to the area in 1996 made an important advance in the study of the ocean floor. It found that a steeply sloping detachment fault is associated with the oceanic core complex structure. The dome was caused by mantle material being extruded to
30-425: The massif is around 700 metres (2,297 ft) beneath the surface. It is believed that the massif was formed underneath the nearby Mid-Atlantic Ridge but was pulled from under the ridge during the movement of the plates , about 1.5 to 2 million years ago. Geologic studies of the massif have indicated that it is not composed of the black basalt typical of the ocean floor but rather of dense green peridotite , which
36-577: The surface. Another expedition discovered the Lost City hydrothermal field near the summit of the ridge in 2000. Another expedition in 2016, the IODP 357 expedition , targeted this massif, drilling cores. Massif A massif ( / m æ ˈ s iː f , ˈ m æ s ɪ f / ) is a principal mountain mass, such as a compact portion of a mountain range , containing one or more summits (e.g. France's Massif Central ). In mountaineering literature,
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