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Tectonic plates are either oceanic crust and/or continental crust and the upper solid layer of the mantle. The continental crust is composed of felsic (rich in feldspars and silica) rocks and the oceanic crust of mafic (rich in magnesium and iron) rocks. The mantle however is composed of peridotite (which is ultramafic meaning it has very high concentrations of the denser magnesium and iron minerals). As such it is much denser than either the mafic or felsic rocks of the crust and the density increases with increasing depth.
The crust and solid upper mantle are known together as the lithosphere as they have similar mechanical properties (behaving as a brittle solid) and are separated into the tectonic plates which effectively float on the underlying asthenosphere which is a denser plastic like zone below them the mantle.
Ultimately the "floating" of tectonic plates on the upper mantle is due to the density contrast between the materials composing the lithosphere and asthenosphere.
Wiki User
∙ 14y ago
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∙ 14y agoContinental rocks are less dense than mantle rock.
Wiki User
∙ 13y agoThe crust floats on top of the mantle because it is buoyant as it is less dense than the material that composes the mantle.
Wiki User
∙ 11y agoTectonic plates float on the mantle because they are less dense
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∙ 13y agoThey are made of lighter/less dense material than what they float on. i think.
Wiki User
∙ 13y agoThey float because, they are lighter and bouyant.
Wiki User
∙ 13y agoThe core float on top of the mantle because the air pressure between the mantle and the crust puts enough pressure to make the crust float
Wiki User
∙ 11y agothe lithosphere plates float on the asthenosphere because of plasticity...
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Do the earth's continents move?
The continents are situated on top of tectonic plates which float on the Earth's magma under the crust. This means that the plates move about, which means yes, the continents will move but it will be very, VERY slow.
How does the internal structure of the earth influence the creation of continents oceans and mountain ranges?
Its a liquid ball on which solids float - and move around.
How does the internal structure of the earth influence the creation of continents oceans and mountains ranges?
Its a liquid ball on which solids float - and move around.
Continents float on the Earth's mantle because continental rocks are 'blank' than mantle rock.?
Continental rock is less dense than mantle rock.
What layer of earth forms the continents?
the crust. the layer below that is the layer of molten lava called the mantle. the continental plates move and float on this. this is known as continental drift
Does Antarctica float?
Antarctica is a continent: continents do not float.
Do the seven continents float on water?
No, they float on the mantle, which is made of ultramafic rock softened by intense heat.
Did larger continents broke through the oceanic crust?
No, they float on it.
Continents float high because they are?
Less dense than the mantle
How can fossils be found on all continents?
dinos die then they float across the water
Why do the earths continents float on the liquids mantle of the earth?
The continents "float" on the liquid mantle of the Earth because the metals that make up the mantle are very dense. The continents move when magma is pushed through the crust of the Earth in places like the Mid-Atlantic Ridge. The continents "float" on the liquid mantle of the Earth because the metals that make up the mantle are very dense. The continents move when magma is pushed through the crust of the Earth in places like the Mid-Atlantic Ridge.
Did wind push continents together?
No. The continents 'float' on a huge reservoir of magma - melted rock - and the deep underground/undersea forces push the continents slowly but unstoppably around on the surface of the globe.
Why do continents float high relative to the ocean basin?
The continents are thicker and less dense than the materials that make up the ocean basins.
What layer are the continents sliding down?
The continents are located on Continental plates, which "float" and "slide" along the Asthenosphere, which is the "gooey" upper mantle and lower part of the crust.
Why are continents not fixed permanently in location on the earths crust?
The continents are embedded in the top side of crustal plates which float on the surface of the mantle. Convection currents in the mantle carry the plates around and the embedded continents travel along.
How can such heavy things as the continents float?
Continents float because the rock beneath them is denser then the surface rocks The surface rocks are poorer in iron than the deeper layers. The continents are made mostly of silica rich rock, which is less dense than oceanic crust, so when the two come in contact, the oceanic crust sinks beneath the continent.
What is the ocean of molten rock on which the continents float called?
There is no ocean of molten rock underneath the continents. Tectonic plates, both oceanic and continental, move on top of the ductile asthenosphere.
