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Continental crust. Land relief

Continental crust. Land relief

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The continental earth's crust, whose example can be seen in the image, is the outer rock layer of the Earth. The materials of which it is composed can be traced back to 4,000 years ago, and is much older than the oceanic crust.

The continental crust is the stiffest and coldest layer of the earth. It has a thickness close to 40 kilometers, although in some areas of orogeny it can reach 60 or 70 kilometers. The greatest known thickness of the continental crust is under the Himalayan mountain range, and is 75 kilometers.

It has two zones, the upper and lower continental crust, the latter much less known. On the upper continental crust the continents arose, and is formed by igneous, sedimentary and metamorphic rocks. For its part, the lower continental crust is believed to be composed primarily of granite of plutonic origin.

To investigate the continental crust, perforations are carried out by means of soundings that can reach up to 12 kilometers. Geophysical methods such as seismology or gravimetry can also be used. Volcanology, petrography and geochemistry are also used to analyze and study the Earth's continental crust.

The continental crust, which also includes areas of the shallow sea, is constantly being renovated. This is due to tectonic movements, erosion, volcanism or sedimentation.

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Geological cycleOceanic crust
Album: Photos of the Earth and the Moon Gallery: The land relief