Banded iron formation deposit

Ore deposit

Precambrian sea floors where oxygen from the first photosynthesisers met dissolved iron and laid down iron oxide and chert in bands, over hundreds of kilometres. They hold more than three fifths of the world's iron reserves.

Where

Plateau

Rocks

Banded iron formation, Jasper

Minerals

Hematite, Magnetite, Siderite, Quartz, Tiger's Eye

Metals

Iron

Worked

Since the industrial age

Examples

Hamersley Range, Western Australia; Mesabi Range, Minnesota, worked since 1892; Northern Michigan, where the first was found in 1844

Sources

• Banded iron formation. Wikipedia.
• Mesabi Range. Wikipedia.

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