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How deep is the brittle-ductile transition?

How deep is the brittle-ductile transition?

In general, the brittle-ductile transition occurs at relatively shallow depths in warm and young crust (10–20 km), whereas in cool and old crust, it occurs at greater depths (20–30 km).

Which crust is brittle?

The upper 20-25 km of the continental crust is the coldest and strongest part of the tectonic plates, and because cold rock is brittle, it generates most of the earthquakes.

Are rocks brittle in deep crust?

Earthquakes and faults occur in the shallow crust, where rocks are relatively cold and therefore brittle. In the deep crust and in the earth’s mantle, rocks are very hot and subject to high pressure caused by the weight of the overlying rock. The heat and pressure cause deep crustal and mantle rocks to be ductile.

How thick is the lower crust?

Abstract. Global observations show that the crustal thickness varies through the tectonic regions. While the continental crust is 30–70 km thick, the oceanic crustal thickness is 6–12 km.

Is the upper crust brittle?

The brittle-ductile transition zone (hereafter the “transition zone”) is the zone of the Earth’s crust that marks the transition from the upper, more brittle crust to the lower, more ductile crust.

Is the earth’s crust brittle?

Like the shell of an egg, the Earth’s crust is brittle and can break.

How thick is the continental crust in km?

35 – 70 km
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.

How thick is the oceanic crust in km?

6–7 km
On average, oceanic crust is 6–7 km thick and basaltic in composition as compared to the continental crust which averages 35–40 km thick and has a roughly andesitic composition.

Is the lower crust brittle?

What is brittle deformation?

Brittle deformation refers to the shape change of a material by breaking of its chemical bonds, which do not subsequently reform. In natural rocks, the result of brittle deformation is often manifested as fractures, especially faults and joints.

How far deep is the Earth’s crust?

Earth’s crust is between three and 46 miles (five and 75 km) deep. The thickest parts are under the continents and the thinnest parts are under the oceans.

How thick is the Earth’s crust in km?

Beneath the oceans, the crust varies little in thickness, generally extending only to about 5 km. The thickness of the crust beneath continents is much more variable but averages about 30 km; under large mountain ranges, such as the Alps or the Sierra Nevada, however, the base of the crust can be as deep as 100 km.