Huge deposits have been found in banded iron formations.
These iron formations are abundant in the Lake Superior region.
Huge deposits of hematite are found in banded iron formations.
Here, up to 300 million years is represented by a single unit of banded iron formation and shale.
A productive belt of iron formations is known as an iron range.
They are smaller in size and less likely to be deformed or metamorphosed than iron formations.
However, iron formations are mainly Precambrian in age which means that they are 4600 to 590 million years old.
Large deposits of iron are found in banded iron formations.
Furthermore, there is a banded iron formation present in the bluffs.
Samples taken from the iron formation have shown up to 37.71% Fe.