Mantle (geology)

Template:Short description {{#invoke:other uses|otheruses}} Template:Pp-vandalism A mantle is a layer inside a planetary body bounded below by a core and above by a crust. Mantles are made of rock or ices, and are generally the largest and most massive layer of the planetary body. Mantles are characteristic of planetary bodies that have undergone differentiation by density. All terrestrial planets (including Earth), half of the giant planets, specifically ice giants, a number of asteroids, and some planetary moons have mantles.

Examples

Earth

The internal structure of Earth

Template:Main The Earth's mantle is a layer of silicate rock between the crust and the outer core. Its mass of 4.01 × 10²⁴ kg is 67% of the mass of the Earth.<ref name=":02">Template:Cite book</ref> It has a thickness of Template:Convert<ref name=":02" /> making up about 84% of Earth's volume. It is predominantly solid, but in geological time it behaves as a viscous fluid. Partial melting of the mantle at mid-ocean ridges produces oceanic crust, and partial melting of the mantle at subduction zones produces continental crust.<ref>Template:Cite news</ref>

Other planets

Mercury has a silicate mantle approximately Template:Convert thick, constituting only 28% of its mass.<ref name=":02" /> Venus's silicate mantle is approximately Template:Convert thick, constituting around 70% of its mass.<ref name=":02" /> Mars's silicate mantle is approximately Template:Convert thick, constituting ~74–88% of its mass,<ref name=":02" /> and may be represented by chassignite meteorites. Uranus and Neptune's ice mantles are approximately 30,000 km thick, composing 80% of both masses.<ref>Template:Cite journal</ref>

Moons

Jupiter's moons Io, Europa, and Ganymede have silicate mantles; Io's ~Template:Convert silicate mantle is overlain by a volcanic crust, Ganymede's ~Template:Convert thick silicate mantle is overlain by ~Template:Convert of ice, and Europa's ~Template:Convert km silicate mantle is overlain by ~Template:Convert of ice and possibly liquid water.<ref name=":02" />

The silicate mantle of the Earth's moon is approximately 1300–1400 km thick, and is the source of mare basalts.<ref name=":0">Template:Cite journal</ref> The lunar mantle might be exposed in the South Pole-Aitken basin or the Crisium basin.<ref name=":0" /> The lunar mantle contains a seismic discontinuity at ~Template:Convert depth, most likely related to a change in composition.<ref name=":0" />

Titan and Triton each have a mantle made of ice or other solid volatile substances.<ref name="TitanMantle2">Template:Cite web</ref><ref name="TritonMantle2">Template:Cite web</ref>

Asteroids

Some of the largest asteroids have mantles;<ref>Template:Cite web</ref> for example, Vesta has a silicate mantle similar in composition to diogenite meteorites.<ref>Template:Cite journal</ref>

See also

• Earth's internal heat budget
• Lehmann discontinuity
• Mantle xenoliths
• Mantle convection
• Mesosphere (mantle)
• Numerical modeling (geology)
• Primitive mantle

Further reading

• Don L. Anderson, Theory of the Earth, Blackwell (1989), is a textbook dealing with the Earth's interior and is now available on the web. Retrieved 2007-12-23.
• Template:Cite book
• Nixon, Peter H. (1987). Mantle xenoliths: J. Wiley & Sons, 844p., (Template:ISBN).
• Donald L. Turcotte and Gerald Schubert, Geodynamics, Cambridge University Press, Third Edition (2014), Template:ISBN (Hardback) Template:ISBN (Paperback)

External links

• The Biggest Dig: Japan builds a ship to drill to the earth's mantle – Scientific American (September 2005) (archived 17 October 2007)
• Information on the Mohole Project (archived 2 November 2015)