magma

American  

[mag-muh] / ˈmæg mə /

noun

plural

magmas, magmata

1. Geology. molten material beneath or within the earth's crust, from which igneous rock is formed.

2. any crude mixture of finely divided mineral or organic matter.

3. Chemistry, Pharmacology. a paste composed of solid and liquid matter.

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magma British  

/ ˈmæɡmə, mæɡˈmætɪk /

noun

1. a paste or suspension consisting of a finely divided solid dispersed in a liquid

2. hot molten rock, usually formed in the earth's upper mantle, some of which finds its way into the crust and onto the earth's surface, where it solidifies to form igneous rock

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magma Scientific  

/ măg′mə /

1. The molten rock material that originates under the Earth's crust and forms igneous rock when it has cooled. When magma cools and solidifies beneath the Earth's surface, it forms what are known as intrusive rocks. When it reaches the Earth's surface, it flows out as lava and forms extrusive (or volcanic) rocks.

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magma Cultural  

1. Molten rock usually located deep within the mantle of the Earth that occasionally comes to the surface through cracks in the mantle or through the eruption of volcano es.

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Usage

What’s the difference between magma and lava? Magma is what molten (melted) rock is called when it’s under the earth’s surface. Lava is what molten rock is called when it flows out of a volcano or volcanic vent.To be clear, in popular use, magma and lava are essentially different names for the same liquid-hot, charred orange ooze—which name is used depends on whether it is above or below the surface.However, geologists and volcanologists have their reasons for using the two different terms to distinguish between forms of what is the same substance.Magma doesn’t always become lava—sometimes it cools and solidifies beneath the earth's surface. Sometimes, it collects in what’s known as a magma chamber. When it does reach the surface, it flows out as lava. The rock that’s formed when it hardens and cools can also be called lava, though this use of the term is uncommon outside of technical, scientific contexts.The word lava is perhaps the more well-known of the two because that’s the one we see when volcanoes erupt (or when the floor turns into it).Here is an example of magma and lava used correctly in the same sentence.Example: Lava began flowing from the volcano three days after scientists detected movement of magma underground.Want to learn more? Read the full breakdown of the difference between magma and lava.

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When magma cools and solidifies, it forms igneous rock, of which lava is one type.

Other Word Forms

• magmatic adjective
• magmatism noun

Etymology

Origin of magma

1400–50; late Middle English < Latin: dregs, leavings < Greek mágma kneaded mass, salve, equivalent to mag- (base of mássein to knead, press; mass ) + -ma noun suffix of result

Example Sentences

Much of Earth was covered by a global ocean of magma, with temperatures so extreme that liquid water could not survive.

From Science Daily

A global magma ocean might move some heat from the dayside toward the nightside, but without an atmosphere the permanently dark side would solidify, limiting how much energy could be redistributed.

From Science Daily

Strontium isotopes: Different forms of the element strontium used by scientists to determine the origin and history of rocks and magmas.

From Science Daily

Rising magma heats these buried layers, producing methane and other hydrocarbons.

From Science Daily

As bubbles accumulate, the magma becomes more buoyant and rises faster, sometimes tearing apart and erupting explosively.

From Science Daily

Related Words

• basalt
• slag