Igneous intrusion

For other uses, see Igneous intrusion (disambiguation).

Not to be confused with plutoid or plutino.

"Plutonic" redirects here. For the Australian gold mine, see Plutonic Gold Mine.

A Jurassic pluton of pink monzonite intruded below a section of gray sedimentary rocks and then was subsequently uplifted and exposed, near Notch Peak, House Range, Utah.

In geology, a pluton is a body of intrusive igneous rock (called a plutonic rock) that is crystallized from magma slowly cooling below the surface of the Earth. Plutons include batholiths, stocks, dikes, sills, laccoliths, lopoliths, and other igneous formations. In practice, "pluton" usually refers to a distinctive mass of igneous rock, typically several kilometers in dimension, without a tabular, or flat, shape like those of dikes and sills. Examples of plutons include Denali (formerly Mount McKinley) in Alaska; Cuillin in Skye, Scotland; Cardinal Peak in Washington State; Mount Kinabalu in Malaysia; and Stone Mountain in the US state of Georgia.

The most common rock types in plutons are granite, granodiorite, tonalite, monzonite, and quartz diorite. Generally light colored, coarse-grained plutons of these compositions are referred to as granitoids.

Etymology

The term originated from Pluto, the classical god of the underworld. The use of the name and concept goes back to the beginnings of the science of geology in the late 18th century and the then hotly debated theories of plutonism (or vulcanism), and neptunism regarding the origin of basalt.

See also

• Methods of pluton emplacement
• Subvolcanic rock
• Volcanic rock

References

• Glazner, A. F., Bartley, J. M., Coleman, D. S., Gray, W. and Taylor, R. Z. (2004). "Are plutons assembled over millions of years by amalgamation from small magma chambers?" GSA Today, 14 (4: April), pp. 4–11.
• Young, Davis A. (2003). Mind Over Magma: the Story of Igneous Petrology. Princeton University Press. ISBN 0-691-10279-1.

Further reading

• Best, Myron G. (1982). Igneous and Metamorphic Petrology. San Francisco: W. H. Freeman & Company. pp. 119 ff. ISBN 0-7167-1335-7.