Table of Contents
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 the similarities and differences between the 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 two things are similar to oceanic 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.
Are oceanic and continental plates the same?
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.
What is the relationship between oceanic and continental crust?
There is also evidence that continental crust is formed through an accretionary process known as relamination. As an oceanic plate subducts underneath a continental plate, it pulls ocean floor sediment, magma, and larger concentrations of rock along with it.
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 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 3 differences between oceanic and continental crust?
The oceanic crust is mainly made out of dark basalt rocks that are rich in minerals and substances like silicon and magnesium. By contrast, the continental crust is made up of light-colored granite rocks full of substances like oxygen and silicon. The continental crust is older than the oceanic crust.
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.
Why continental crust is thicker than oceanic crust?
The continental crust is also less dense than oceanic crust, although it is considerably thicker. Because of its relative low density, continental crust is only rarely subducted or recycled back into the mantle (for instance, where continental crustal blocks collide and over thicken, causing deep melting).
What are the 2 oceanic plates?
An example of an oceanic plate is the Pacific Plate, which extends from the East Pacific Rise to the deep-sea trenches bordering the western part of the Pacific basin. A continental plate is exemplified by the North American Plate, which includes North America as well as the oceanic 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 are characteristics of oceanic plates?
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.
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.
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 crust composition?
Crust. Tarbuck, Earth’s crust is made up of several elements: oxygen, 46.6 percent by weight; silicon, 27.7 percent; aluminum, 8.1 percent; iron, 5 percent; calcium, 3.6 percent; sodium, 2.8 percent, potassium, 2.6 percent, and magnesium, 2.1 percent.
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.
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.
Why continental crust is granite?
Continental crust is indeed “granitic”, and has the general composition typical of granitic rocks, made up of mostly aluminium silicates (the SiAl). These intermediate and acid igneous rocks (like granite, andesite and rhyolite) then form the basic materials from which continent-derived sediments are formed.
What are the difference between the two types of crust?
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. The thin oceanic crust is composed of primarily of basalt, and the thicker continental crust is composed primarily of granite.
