banded iron formation

noun

Definition of banded iron formation 

geology

: a sedimentary deposit that consists of alternating thin layers of iron oxides (such as magnetite or hematite) and iron-poor minerals (such as shale or chert) That bedrock includes intriguing structures known as banded iron formations, which are believed to occur only with the help of living organisms.— Kenneth Chang, New York Times, 2 Dec. 2008

Note: Banded iron formations, which formed over a billion years ago, are often used today as a source of low-grade iron ore.

abbreviation BIF

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First Known Use of banded iron formation

1903, in the meaning defined above

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The first known use of banded iron formation was in 1903

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