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An upper mantle body is a geological region where upper mantle rocks outcrop on the surface of the Earth (including the ocean floor). Upper mantle outcrops include: upper mantle made at constructive plate boundaries, but preserved in ophiolites, for example Isabela ophiolite in the Philippines [1] upper mantle above subduction zones, so called ...
In species where the shell is small compared to the size of the body, more of the mantle shows. Shell-less slugs have the mantle fully visible. The dorsal surface of the mantle is called the notum, while the ventral surface of the mantle is called the hyponotum. In the family Philomycidae, the mantle covers the whole back side of the body. [2]
At a subduction zone the relatively cold, dense oceanic crust sinks down into the mantle, forming the downward convecting limb of a mantle cell, which is the strongest driver of plate motion. The relative importance and interaction of other proposed factors such as active convection, upwelling inside the mantle, and tidal drag of the Moon is ...
The transition zone is located between the upper mantle and the lower mantle between a depth of 410 km (250 mi) and 670 km (420 mi).. This is thought to occur as a result of the rearrangement of grains in olivine to form a denser crystal structure as a result of the increase in pressure with increasing depth. [6]
Scientists believe they’ve discovered an ancient ocean floor comprising a new layer between Earth’s mantle and core.
Ophiolite basalt contents place them in the domain of subduction zones (~55% silica, <1% TiO 2), whereas mid-ocean ridge basalts typically have ~50% silica and 1.5–2.5% TiO 2. These chemical differences extend to a range of trace elements as well (that is, chemical elements occurring in amounts of 1000 ppm or less). In particular, trace ...
The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of the ocean is very deep, where the seabed is known as the abyssal plain. Seafloor spreading creates ...
The oceanic zone is typically defined as the area of the ocean lying beyond the continental shelf (e.g. the neritic zone), but operationally is often referred to as beginning where the water depths drop to below 200 metres (660 ft), seaward from the coast into the open ocean with its pelagic zone.