The term "metamorphosis" is most oft used in reference to the process of a caterpillar changing into a butterfly. Nevertheless, the give-and-take "metamorphosis" is a broad term that indicates a modify from ane thing to another. Even rocks, a seemingly constant substance, can change into a new blazon of stone. Rocks that undergo a change to form a new rock are referred to as metamorphic rocks.

In the stone cycle, there are iii dissimilar types of rocks: sedimentary, igneous, and metamorphic. Sedimentary and igneous rocks began equally something other than rock. Sedimentary rocks were originally sediments, which were compacted under high pressure. Igneous rocks formed when liquid magma or lava—magma that has emerged onto the surface of the World—cooled and hardened. A metamorphic rock, on the other hand, began as a rock—either a sedimentary, igneous, or even a unlike sort of metamorphic rock. And then, due to various conditions inside the Earth, the existing rock was inverse into a new kind of metamorphic rock.

The conditions required to form a metamorphic rock are very specific. The existing rock must exist exposed to high oestrus, high pressure level, or to a hot, mineral-rich fluid. Commonly, all three of these circumstances are met. These conditions are most often establish either deep in Globe'southward crust or at plate boundaries where tectonic plates collide. In guild to create metamorphic rock, it is vital that the existing stone remain solid and not melt. If there is likewise much heat or force per unit area, the rock volition melt and get magma. This will result in the formation of an igneous stone, not a metamorphic rock.

Consider how granite changes form. Granite is an igneous stone that forms when magma cools relatively slowly secret. It is ordinarily composed primarily of the minerals quartz, feldspar, and mica. When granite is subjected to intense estrus and pressure, information technology changes into a metamorphic rock called gneiss.

Slate is another common metamorphic stone that forms from shale. Limestone, a sedimentary rock, will alter into the metamorphic rock marble if the right conditions are met.

Although metamorphic rocks typically form deep in the planet's crust, they are frequently exposed on the surface of the Earth. This happens due to geologic uplift and the erosion of the rock and soil to a higher place them. At the surface, metamorphic rocks will be exposed to weathering processes and may break down into sediment. These sediments could then be compressed to form sedimentary rocks, which would start the unabridged cycle anew.

Metamorphic Rocks

Metamorphic stone, estimated to be as old equally iii.8 billion years, located near Isua at Qorqut Sound, Greenland.

Noun

rock formed past the cooling of magma or lava.

lava

Noun

molten rock, or magma, that erupts from volcanoes or fissures in the Earth's surface.

Noun

molten, or partially melted, rock beneath the Earth'south surface.

metamorphic stone

Substantive

stone that has transformed its chemic qualities from igneous or sedimentary.

Noun

movement and interaction of the Earth's plates.

Noun

processes that explain the human relationship between the three rock types: igneous, sedimentary, and metamorphic. Whatever rock blazon can become any other.

Noun

rock formed from fragments of other rocks or the remains of plants or animals.

uplift

Noun

elevation of the Globe'south surface due to tectonic or other natural activity.

  • Credits

    Media Credits

    The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

    Director

    Tyson Brown, National Geographic Guild

    Author

    National Geographic Society

    Production Managers

    Gina Borgia, National Geographic Club
    Jeanna Sullivan, National Geographic Club

    Plan Specialists

    Sarah Appleton, National Geographic Society
    Margot Willis, National Geographic Guild

    Producer

    Clint Parks

    Concluding Updated

    Oct. x, 2019

  • User Permissions

    For data on user permissions, please read our Terms of Service. If you accept questions well-nigh how to cite anything on our website in your project or classroom presentation, delight contact your teacher. They will best know the preferred format. When y'all reach out to them, you volition need the page title, URL, and the date you lot accessed the resource.

    Media

    If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, yous cannot download or salve the media.

    Text

    Text on this page is printable and can exist used co-ordinate to our Terms of Service.

    Interactives

    Any interactives on this page tin can just be played while you lot are visiting our website. You cannot download interactives.