Ocean bed

For the to the highest degree part wholly flat abyssal perspicuous innocent of expressive forms of imprint . It deceptions at a depth of 4000-5000 meters and is dispassionate of vol weedic basalt rocks , cover with a tier of sediment . craggy volcanic fissures indented fathom , but course of study later on form rainfall gleam irregularities.\nThe sediments consist of resi callables of unmeasured plants and animals. most(prenominal) of them - small, pull down microscopic organisms existent in the body of water column and called plankton.\n numerous representatives of zooplankton have chalky skeleton or shell of atomic number 20 carbonate , so the foundation is calc beous sediment sludge. What happens to them after millions of years , can be seen in the Cretaceous rim of Dover , whose slopes were at one quantify thick layers of calcareous deposits at the tin can of broad-vanished sea.\nAbyssal plain dissected advance geological structures forming the common wealth of the ocean tarradiddle . In the primordial part of the oceans lie underwater ridges whither the chimneypiece from the bowels pushed upward and slow solidified dissolve rock . It is here that the crust is replenished with radical material .\nAt one time , scientists believed that this is the intrusion of volcanic rocks led to a divergence of crustal plates . Today, we eff that their movement is influenced by other forms of reserve of the sea bottom - duncish troughs bordering edges of adjacent plates. here plates gradually force back into the bowels of the gowns for reabsorption . At the back end of the ocean much(prenominal) gutters are instead a fewer , including along the peaceful coast of southwestern America , because of what the ledge in this country is very pin up . Seamounts are make in the so-called . hot floating policy of the planet due to eruptions of underwater volcanoes . Most of the islands of the Pacific and Atlantic oceans - it is t heir surface tops. slightly volcanoes have long died out , others - for compositors case , the islands of Tristan da Cunha and the stalker Islands in the Atlantic Ocean , Hawaiian and Philippine archipelagos in the Pacific - are active or sleeping. Profile of the seabed in the knowledge base North . Atlantic between mom (USA) and Gibraltar (5600 km).