banded iron formation
noun
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) —abbreviation BIF
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
Kenneth Chang, New York Times, 2 Dec. 2008Note: Banded iron formations, which formed over a billion years ago, are often used today as a source of low-grade iron ore.
Word History
First Known Use
1903, in the meaning defined above
- back straddle vault
- back stream
- back swath
- back talk
- back taper
- back tendon
- back then
- back to front
- back trail
- back turn
- back up
- back up or away
- back vent
- back venting
- back-alley
- back-and-forth
- back-and-forthing
- back-and-forths
- back-arc
- back-arcs
- back-burn
- back-burned
- back-burner
- back-burning
- back-burns