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Continental crust consists mainly of less dense rocks such as granite. Oceanic crust consists of mainly denser rocks such as basalt. Oceanic crust is denser than continental crust. the layer of hot, solid material between Earth’s crust and core.
What are the two differences between oceanic crust 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.
What are the main differences between oceanic crust and continental crust quizlet?
The oceanic crust is thinner and denser, and is similar in composition to basalt (Si, O, Ca, Mg, and Fe). The continental crust is thicker and less dense, and is similar to granite in composition (Si, O, Al, K, and Na).
What are the similarities between oceanic and continental crust?
Oceanic and Continental crusts are alike because they both shift and move and grow. They differ by there rock types. Oceanic crust is made up of dense basalt while continental crust is made up of less dense granite.
What is an example of continental crust?
The continental crust is the layer of granitic, sedimentary and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as continental shelves. About 40% of the Earth’s surface is now underlain by continental crust.
What are the two types of crust?
Earth’s crust is divided into two types: oceanic crust and continental crust. The transition zone between these two types of crust is sometimes called the Conrad discontinuity. Silicates (mostly compounds made of silicon and oxygen) are the most abundant rocks and minerals in both oceanic and continental crust.
What are the characteristic of continental crust?
Continental crust is broadly granitic in composition and, with a density of about 2.7 grams per cubic cm, is somewhat lighter than oceanic crust, which is basaltic (i.e., richer in iron and magnesium than granite) in composition and has a density of about 2.9 to 3 grams per cubic cm.
How can continental crust be accreted?
Accretion is a process by which material is added to a tectonic plate or a landmass. Water and gas helps low-temperature minerals to melt and rise as, forming new continental crust (less dense than oceanic crust). Jan 5, 2017.
How many continental crust are there?
There are currently about 7 billion cubic kilometers of continental crust, but this quantity varies because of the nature of the forces involved. The relative permanence of continental crust contrasts with the short life of oceanic crust.
Why is it important to distinguish the two types of crust?
Explanation: The thin oceanic crust is composed of primarily of basalt, and the thicker continental crust is composed primarily of granite. The low density of the thick continental crust allows it to “float” in high relief on the much higher density mantlebelow.
What is called lower layer of the crust?
In geology, sima (/ˈsaɪmə/) is an antiquated blended term for the lower layer of Earth’s crust. The sima layer is also called the ‘basal crust’ or ‘basal layer’ because it is the lowest layer of the crust. Because the ocean floors are mainly sima, it is also sometimes called the ‘oceanic crust’.
How thick is Earth’s crust?
Earth’s crust is 5 to 70 km thick. Continental crust makes up the land on Earth, it is thicker (35 – 70 km), less dense and mostly made up of the rock granite. Oceanic crust makes up most of the ocean, it is thinner (5 – 7 km), denser and mostly made up of the rock basalt.
What are the two kinds of crust and its definition?
Earth’s Crust There are two different types of crust: thin oceanic crust that underlies the ocean basins, and thicker continental crust that underlies the continents. These two different types of crust are made up of different types of rock.
Why is continental crust higher than oceanic crust?
Layers that are less dense, such as the crust, float on layers that are denser, such as the mantle. 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.
Which two terms apply to oceanic crust rather than continental crust?
Oceanic crust differs from continental crust in several ways: it is thinner, denser, younger, and of different chemical composition. Like continental crust, however, oceanic crust is destroyed in subduction zones.
What is an example of continental accretion?
Most continents are composed of multiple accreted “terranes,” pieces of low-density continental crust with different origins. For example, North America is made up of multiple accreted terranes that collided with the Laurentian proto-continent, such as the Proterozoic Yavapai, Mazatzal, and Grenville Province Terranes.
Which is denser continental crust or oceanic crust?
Oceanic crust is generally composed of dark-colored rocks called basalt and gabbro. It is thinner and denser than continental crust, which is made of light-colored rocks called andesite and granite.
What happens at a continental rift zone?
Where tectonic plates move away from one another the lithosphere thins. The underlying asthenosphere rises and expands like a hot-air balloon, elevating a broad region. If the plate is capped by thick continental crust, the resulting continental rift zone rises high above sea level.
What is the average age of continental crust?
On the basis of Nd model age provinces in North America and Australia an average age of continental crust is about 2.0 Ga.
What is the age of continental crust?
The oldest oceanic crust is about 260 million years old. This sounds old but is actually very young compared to the oldest continental rocks, which are 4 billion years old.
Which type of crust is usually the oldest?
Cratons are the oldest and most stable part of the continental lithosphere. These parts of the continental crust are usually found deep in the interior of most continents.
