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Earth's crust. Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a division of Earth's layers that includes the crust and the upper part of the mantle. [1] The lithosphere is broken into tectonic plates whose motion allows heat to ...
Sharp rises occur in the uppermost mantle and at the core–mantle boundary. Geothermal gradient is the rate of change in temperature with respect to increasing depth in Earth 's interior. As a general rule, the crust temperature rises with depth due to the heat flow from the much hotter mantle; away from tectonic plate boundaries, temperature ...
At the conditions under the earth's crust of extreme high temperature and pressure, rocks are ductile. They can bend, fold or break. Other vital conditions that contribute to the formation of structure of rock under the earth are the stress and strain fields. Stress-strain curve. Stress is a pressure, defined as a directional force over area.
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. [1] For quartz and feldspar -rich rocks in continental crust, the transition zone occurs at an approximate depth of 20 km, [2] at temperatures of ...
In structural geology, a fold is a stack of originally planar surfaces, such as sedimentary strata, that are bent or curved ( "folded") during permanent deformation. Folds in rocks vary in size from microscopic crinkles to mountain-sized folds. They occur as single isolated folds or in periodic sets (known as fold trains ).
Mantle convection. Simplyfied model of mantle convection: [1] Whole-mantle convection. Mantle convection is the very slow creep of Earth's solid silicate mantle as convection currents carry heat from the interior to the planet's surface. [2] [3] Mantle convection causes tectonic plates to move around the Earth's surface.
Asthenosphere. The asthenosphere (from Ancient Greek ἀσθενός (asthenós) 'without strength') is the mechanically weak [1] and ductile region of the upper mantle of Earth. It lies below the lithosphere, at a depth between ~80 and 200 km (50 and 120 mi) below the surface, and extends as deep as 700 km (430 mi). However, the lower boundary ...
Crust (geology) The internal structure of Earth. In geology, the crust is the outermost solid shell of a planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase (solid crust vs. liquid mantle).