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17 General Characteristics of Oceanic Crust

by Ayu Mesdya

What do you think about the characteristics of the oceanic crust? In this discussion, we will inform about 17 general characteristics of oceanic crust. Below here are the following 17 general characteristics of oceanic crust.

1. Oceanic Crust Formed

Some studies say that the oceanic crust can form when magma comes out of different plate boundaries. At that time it will also cool down quickly due to the presence of water. It is this event that causes the oceanic crust to form.Besides, several new studies do some research on the formation of oceanic crust. That some of the minerals that form the new oceanic crust show the process of forming it more slowly and less uniformly. You may want to read about Effects of Ocean Currents on Economic Activities

2. The Age of Oceanic Crust

Approximately how is the age of oceanic crust? According to geography, the age of the oceanic crust is 200 million years. The oceanic crust is younger than the continental crust of 3.8 billion years old. Some researchers have found that the old ad patch of the oceanic crust is well below the Mediterranean Sea and is about 340 million years old. Of course, it beats the previous record of 100 years. Read more about Main and Common Function of Ocean Currents

3. The Location of Oceanic Crust

Oceanic crust or oceanic plate can be found in the circum-Pacific region. This area is a collision area between the oceanic and continental lithocyte plates. However, there is the oldest part of the oceanic crust that can be found. That is along the middle seas in the subduction zone and the continental shelf. The Subduction Zone lies at the edge of the Pacific Ocean, such as off the coast of Washington, Canada, Alaska, Russia, Japan and Indonesia.

These subduction zone areas are also called Ring of Fire. Where in this case there will be so many earthquakes, tsunamis and some of the biggest, terrible and worst volcanic eruptions happening in the world.

4. The Temperature of Oceanic Crust

One of the other characteristics of the oceanic crust is its temperature. It is said, that the crust temperature will increase according to its depth. Usually, the temperature can reach about 500 degrees Celsius to 1,000 degrees Celsius.However, this is true for the temperature of the earth’s crust. The temperature of the oceanic crust is only about 200-400 degrees Celcius. You may want to read about Characteristics of Ocean Temperature

5. The Thickness of Oceanic Crust

The thickness of the oceanic crust is thinner than the earth’s crust. The thickness of the oceanic crust only has a thickness of fewer than 10 kilometers with a larger density. The mean of the age ranges, it is from 3.3 grams per cubic centimeter. The thickness of the oceanic crust consists of basalt rock, unlike the continental crust that has a thickness of 20-70 km with the main structure is granite.

6. The Layer of Oceanic Crust

The oceanic crust layer is composed of layers of cobalt and aluminum. In this layer, there are several types of rocks such as sedimentary rock, andesite granite, metamorphic rocks and others. This layer of crust is solid and this layer is in the present of lithosphere layer.It is said by researchers that in oceanic lithosphere is denser than lithosphere in the continent.

The main reason is the mantle-crust made of felsic rock. Lithosphere in the ocean thickens for centuries and it slowly away from the mid-ocean ridge. This thickening is the causes which are lithosphere in the oceans to become thicker and denser over time.

7. Include The Part of the Lithosphere

The lithosphere is the top layer of the earth with a thickness of fewer than 70 km. It is composed of rocks that are very dense and dark colored. Oceanic crust is one part of the lithosphere that located in the ocean basin. It has been described in the previous point that the oceanic crust is composed of several rock types and they have a lower thickness than the earth’s crust.

8. Basalt Stone

Basalt stone is one type of earth rock formed from magma freezing and it is an alkaline. These stones have several mineral compositions such as Plagioclase feldspar, pyroxene, olivine, magnetite, and ilmenite. This basalt stone is a stone that is often found in the formation of oceanic plates in the world. In the oceanic crust layer, it is also found this type of stones which is one of its compositions.

Basalt stones that are volcanic stones that have been used for centuries in architecture. In ancient Roman history, these stones were used to build roads and monuments. Until today, this basalt stone is still used in the use of architecture. Read more about 3 Common Types of Rocks on Ocean Floor

9. The Density of Oceanic Crust

The facts, although the thickness of the oceanic crust is different (thinner) than the continental crust, the oceanic crust has a higher density. According to some sources explained that the density of oceanic crust ranges from 2.7 grams / cm3. It will be seen from density structures and the mean oceanic crust densities have implications for geological and geophysical problems including the interpretation of gravity data and variations in the lithosphere’s attraction.

10. Metamorphic Rocks

Metamorphic rocks are another type of rock that forms on the shallow seabed near the beach, continental exposure. Metamorphic rocks are caused by metamorphic processes. This process is a process due to changes in pressure, temperature and the presence of chemical activity.

These rocks have index minerals such as sillimanite, kyanite, staurolite, andalusite, as well as olivines, pyroxenes, and others. However, the minerals in these rocks are not found directly in metamorphic rocks. Rather, these minerals formed during the crystallization of igneous rocks. All minerals in this crystallization process are stable at high temperature and pressure.

11. Pillow Lava and Sheet Flows

Oceanic crust is formed at the center of the spread in the oceanic ridges. It occurs at different plate boundaries. Lava is one of the layers in the oceanic crust. There are two common types of lava, namely pillow lavas and sheet flows. The pillow lava measuring about 1 meter across the transverse. These lava shaped small hills at the center of the spread. While the sheet flows have a thin appearance, it is only about 4 inches and it covers a wider area of pillow lavas.

12. Gabbro Layers

In addition, there is pillow lava and sheet flows, under the lava there is a layer measuring more than 1 km consisting of feeder or sheeted. There is also a second layer containing basalt composition with a thickness of about 4.5 km. Both layers are the gabbros layer. This gabbro layer is a magma chamber or a lava pouch that it can erupt on the seafloor

13. Magma Chambers

How did the volcano explode? Lava or magma is a dynamic liquid having a temperature of about 1,300 Fahrenheit to 2,400 Fahrenheit. Magma moves upward toward the surface of the earth through a path that is found. When magma does not allow for the way up, it will collect it in a large pool which is called the magma chambers. The magma chamber is an area beneath the surface of the earth where many rock pools are collected.

Magma is produced by smelting the earth’s mantle and rising below the ocean’s surface. Then, it erupts on the surface of the earth, it cools down, and finally, it forms a basalt. Basalt stones are found at the bottom of the oceanic crust. You may want to read about Risks to the Great Barrier Reef

14. Subduction Zones

The subduction zone is known as a geological process on the convergent boundaries of tectonic plates. In this process, one plate moves below the other and sinks due to gravity into the mantle. Some researchers said that the subduction zones are formed when continental crust and oceanic crust collide.

The thinner oceanic crust causes subduction of the oceanic crust to sink under a thicker continental crust. The depth of the plate can reach 50 to 100 miles away. Upon entering the depths the oceanic crust releases the fluid trapped inside it. The melted liquids are rich in silica minerals which is produce basaltic magma.

15. Hydro-Thermal Vents

We know that hydrothermal vents are one of the wonders found on the ocean floor. Typically, these are found near the place or zone of active volcanoes like the Mid-Ocean Ridge. This hydrothermal vent is a seawater that seeps through the oceanic crust that lies around the subduction zones. The cold seawater is heated by hot magma and eventually forms the vents. Seawater in hydrothermal vents can reach temperatures above 700 degrees Fahrenheit.

16. The Life Cycle of Oceanic Crust

The life cycle of the oceanic crust is dominated by the existing rock cycle. Different types of rocks will transition for millions of years. Some examples of igneous rocks such as basalt, granite, and andesite. These igneous rocks are formed by the cooling process and liquid magma crystallization in volcanoes and mid-ocean mountains.

However, over time, these igneous rocks will experience weathering and erosion from exposure to water and the atmosphere. It is from igneous rocks to sedimentary rocks and the last cycle of these rocks is the formation of metamorphic rocks which have been described in previous points. Read more about Social Effects of Ocean Pollution

17. Rich in Iron and Magnesium

Finally, one thing to remember in oceanic crust characteristics. That the oceanic crust is rich in iron and magnesium. Described by several sources that the oceanic crust is composed of mafic rock or sima that are rich in iron and magnesium also silica (poor).

While the continental crust is rich in silica or felsic which it makes the continental crust has less density than the oceanic crust. Iron and magnesium richness is also found in lower gabbro layers, the layered structure is cumulate. This layer has a thickness of several meters which it results from mineral sedimentation coming out of the liquid magma.

Hopefully, this post 17 General Characteristics of Oceanic Crust may benefit for us. With this post, it is expected to help you to know what are the general characteristics of the oceanic crust.

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