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Spreading rate is the rate at which an ocean basin widens due to seafloor spreading. (The rate at which new oceanic lithosphere is added to each tectonic plate on either side of a mid-ocean ridge is the spreading half-rate and is equal to half of the spreading rate). Spreading rates determine if the ridge is fast, intermediate, or slow.
This feature is where seafloor spreading takes place along a divergent plate boundary. The rate of seafloor spreading determines the morphology of the crest of the mid-ocean ridge and its width in an ocean basin. The production of new seafloor and oceanic lithosphere results from mantle upwelling in response to plate separation.
Marine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor.These particles either have their origins in soil and rocks and have been transported from the land to the sea, mainly by rivers but also by dust carried by wind and by the flow of glaciers into the sea, or they are biogenic deposits from marine organisms or from ...
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 ...
Harry Hess proposed the seafloor spreading hypothesis in 1960 (published in 1962 [1]); the term "spreading of the seafloor" was introduced by geophysicist Robert S. Dietz in 1961. [2] According to Hess, seafloor was created at mid-oceanic ridges by the convection of the Earth's mantle, pushing and spreading the older crust away from the ridge. [3]
The bathymetric depths on the north side of the fracture zone are 800 to 1,200 m (2,600 to 3,900 ft) shallower than to the south, suggesting the seafloor north of the ridge to be younger. Geologic evidence backs this up, as rocks were found to be 23 to 27 million years younger north of the ridge than to the south.
During the Cretaceous, seafloor spreading created a relatively shallow Atlantic basin at the expense of a deeper Pacific basin. That reduced the world's ocean basin capacity and caused a rise in sea level worldwide.
A two-stage spreading model explains the tectonic evolution in this region. The first major rift motion was seen in the lower/middle Eocene, followed by major seafloor spreading in the late Eocene and early Oligocene. This was followed by a period of 30 Ma of no motion, during which a large amount of evaporites were deposited. After this quiet ...