What resulted to the formation of new oceanic lithosphere?
New oceanic lithosphere is formed by frequent volcanic eruptions along the length of mid-ocean ridges and is pushed outward from them gradually. Old oceanic lithosphere is destroyed when it subducts or dives beneath adjacent plates at subduction zones.
At which type of plate boundary is new oceanic lithosphere formed?
divergent boundary
Where do new oceanic lithosphere forms?
midocean ridges
What happens to oceanic lithosphere as you move away from a mid ocean ridge?
The oceanic lithosphere thickens as it ages and moves away from the mid-ocean ridge. This thickening occurs by conductive cooling, which converts hot asthenosphere into the lithospheric mantle, and causes the oceanic lithosphere to become increasingly dense with age.
Where is the lithosphere thickest thinnest?
Explanation: Lithosphere is all the solid part of the Earth’s surface. So, the crust and oceanic crust are included up to the upper mantle. The oceanic crust’s depth is up to 8 km , up to the upper part of the mantle, the lithosphere is at its thinnest.
At what boundary type is oceanic lithosphere is destroyed?
convergent boundaries
What is happening to the lithosphere?
The lithosphere is broken up into tectonic plates. Oceanic lithosphere consists mainly of mafic(rich in magnesium and iron) crust and ultramafic(over 90% mafic) mantle and is denser than continental lithosphere. It thickens as it ages and moves away from the mid-ocean ridge.
What is Oceanic Oceanic convergent boundary?
At an ocean-ocean convergent boundary, one of the plates (oceanic crust and lithospheric mantle) is pushed, or subducted, under the other (Figure 4.6. It mixes with the overlying mantle, and the addition of water to the hot mantle lowers the crust’s melting point and leads to the formation of magma (flux melting).
What happens when two continents meet head on and neither is subducted?
Continental-continental convergence When two continents meet head-on, neither is subducted because the continental rocks are relatively light and, like two colliding icebergs, resist downward motion. Instead, the crust tends to buckle and be pushed upward or sideways.
What will form when two oceanic plates collide?
A subduction zone is also generated when two oceanic plates collide — the older plate is forced under the younger one — and it leads to the formation of chains of volcanic islands known as island arcs.
What happens when two oceanic plate collide?
When two oceanic plates collide one oceanic plate is eventually subducted under the other. This andesitic magma is formed from the partial melting of the asthenosphere just above the subduction zone. This partial melting of the subducting plate is due to the loss of water as it descends into the mantle.
What happens when two oceanic plates diverge?
When two oceanic plates diverge, underwater ridges and mountain ranges form, such as the mid-Atlantic Ridge. Eventually these mountain ranges can rise above the water to form islands. When two continental plates diverge, great rift valleys can form.
What does Oceanic Oceanic form?
The features of an ocean-ocean subduction zone are the same as those of an ocean-continent subduction zone, except that the volcanic arc will be a set of islands known as an island arc. The older plate subducts into a trench, resulting in earthquakes. Melting of mantle material creates volcanoes at the subduction zone.
What happens when two oceanic plates collide quizlet?
When two oceanic plates collide, the denser plate is subducted and some material rises upward and forms an ISLAND. What happens when two continental plates collide? The continental crust is pushed together and upward to form large MOUNTAIN ranges. Ocean floor is pushed away from a midocean ridge to form new sea floor.
What happens to the oceanic crust during subduction?
At a subduction zone, the oceanic crust usually sinks into the mantle beneath lighter continental crust. (Sometimes, oceanic crust may grow so old and that dense that it collapses and spontaneously forms a subduction zone, scientists think.)
When continental and oceanic plates collide?
When continental and oceanic plates collide, the thinner and more dense oceanic plate is overridden by the thicker and less dense continental plate. The oceanic plate is forced down into the mantle in a process known as “subduction.” As the oceanic plate descends, it is forced into higher temperature environments.
Is continental or oceanic plate more dense?
Both oceanic crust and continental crust are less dense than the mantle, but oceanic crust is denser than continental crust. This is partly why the continents are at a higher elevation than the ocean floor. As a result, the rock that forms from that melt is less dense than the original rock.
How do you tell if a plate is oceanic or continental?
Continental plates are much thicker that Oceanic plates. At the convergent boundaries the continental plates are pushed upward and gain thickness. The rocks and geological layers are much older on continental plates than in the oceanic plates. The Continental plates are much less dense than the Oceanic plates.
What are 3 differences between oceanic and continental crust?
Continental crust is low in density whereas oceanic crust has a higher density. continental crust is thicker, on the contrary, the oceanic crust is thinner. Continental crust floats on magma freely but oceanic crust floats on magma scarcely. Continental crust cannot recycle whereas oceanic crust can recycle it.
Why are oceanic plates more dense?
Oceanic & Continental Plates The oceanic plate is denser and sinks due to its lower buoyancy. It’s sucked into the asthenosphere and is melted deeper into the Earth, called a subduction zone.
Are oceanic plates more thick?
Plates are on average 125km thick, reaching maximum thickness below mountain ranges. Oceanic plates (50-100km) are thinner than the continental plates (up to 200km) and even thinner at the ocean ridges where the temperatures are higher.
Are oceanic plates younger?
Oceanic crust is not only thinner and denser than continental crust, and it is also much younger than it and has a different chemical composition. When magma from the mantle of the earth finds a way up, it comes into contact with water that cools it down quickly. It is forced to take the shape of pillows.
What are the 8 oceanic plates?
The current continental and oceanic plates include: the Eurasian plate, Australian-Indian plate, Philippine plate, Pacific plate, Juan de Fuca plate, Nazca plate, Cocos plate, North American plate, Caribbean plate, South American plate, African plate, Arabian plate, the Antarctic plate, and the Scotia plate.
What are the characteristics of oceanic plate?
Oceanic plates are mafic in nature, composed of basalt rock and its coarse-grained equivalent, gabbro, both rich in iron, magnesium and calcium. In contrast, continental plates are felsic in nature, dominated by granitic rock with its abundant silica, aluminum, sodium and potassium.
What is the largest tectonic plate?
Pacific Plate
What are the 4 types of tectonic plate movement?
There are four types of boundaries between tectonic plates that are defined by the movement of the plates: divergent and convergent boundaries, transform fault boundaries, and plate boundary zones.
Where are most volcanoes located?
Pacific Ocean