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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 are two 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). The mantle is made of magnesium, iron and silicon. The core is almost exclusively iron and nickel.
What are the differences between oceanic and continental?
Oceanic crust is found under oceans, and it is about four miles thick in most places. Continental crust varies between six and 47 miles in thickness depending on where it is found. Continental crust tends to be much older than the oceanic kind, and rocks found on this kind of crust are often the oldest in the world.
What are the four major 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.
What are two physical differences between continental and oceanic crust?
Continental crust is typically 40 km (25 miles) thick, while oceanic crust is much thinner, averaging about 6 km (4 miles) in thickness. The effect of the different densities of lithospheric rock can be seen in the different average elevations of continental and oceanic crust.
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 is the difference between oceanic and continental lithosphere?
Oceanic lithosphere is typically about 50-100 km thick (but beneath the mid-ocean ridges is no thicker than the crust). The continental lithosphere is thicker (about 150 km). It consists of about 50 km of crust and 100 km or more of the uppermost mantle.
What is an example of oceanic crust?
An example of this is the Gakkel Ridge under the Arctic Ocean. Thicker than average crust is found above plumes as the mantle is hotter and hence it crosses the solidus and melts at a greater depth, creating more melt and a thicker crust. An example of this is Iceland which has crust of thickness ~20 km.
Which crust is thicker continental or oceanic?
Earth’s crust is generally divided into older, thicker continental crust and younger, denser oceanic crust.
Is oceanic crust older than continental?
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. As the continental crust is lighter than the oceanic crust, the continental crust cannot subduct.
Which two terms apply to continental crust rather than oceanic 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 crust formation?
An outer layer or coating formed by the drying of a bodily exudate such as pus or blood; a scab.
Why is oceanic crust denser than continental?
In the theory of tectonic plates, at a convergent boundary between a continental plate and an oceanic plate, the denser plate usually subducts underneath the less dense plate. It is well known that oceanic plates subduct under continental plates, and therefore oceanic plates are more dense than continental plates.
What are the characteristics of oceanic crust?
Oceanic crust is thinner and more dense than continental crust. This is because it has been compressed by the weight of the oceans it carries above it. It is also much younger than Continental crust, as it is usually less than 200 million years old.
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.
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.
Where is the oldest oceanic lithosphere?
In the Atlantic Ocean basin, where would the oldest oceanic lithosphere be found? The oldest lithosphere would be in the ridge. Continental Theory is supported by fossils found near coastal regions of south america and africa.
What is the difference between continental and oceanic plates?
Oceanic plates are much thinner than the continental 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.
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 the purpose of oceanic crust?
It creates the crust of the Earth we walk on, and the crust that lies at the ocean floor. Oceanic crust is the part of the Earth’s crust that makes up the seafloor. It’s thinner, denser, and simpler in structure than the continental crust.
What are the four main layers of oceanic crust?
The oceanic crust, on the basis of seismological studies of the seafloor, dredge hauls, drilling, and studies of ophiolites on land, is layered consisting of an upper sedimentary layer, a middle basaltic volcanic layer, and a lower third layer consisting of gabbroic plutonic rocks.
