The deposits of most commercial importance are the limonites and brown hematites found west of the Cumberland Plateau, and the fossiliferous red hematite which crops out along the eastern base of that plateau.
The hematite is also worked at Ulverston, Askam, Dalton and elsewhere, but the furnaces now depend in part upon ore imported from Spain.
There are large beds of hematite some 60 m.
It lies in the midst of the great red and brown hematite iron-ore deposits of the Mesabi Range - the richest in the Lake Superior district - and the mining and shipping of this ore are its principal industries.
High, rich in hematite iron ore; valuable limestone deposits are found some 30 m.
There are deposits of hematite and limestone near the borough, and less than 2 m.
That part of Furness which forms a peninsula between the Leven estuary and Morecambe Bay, and the Duddon estuary, is rich in hematite iron ore, which has been worked from very early times.
Where the Coal Measures reach the sea at Whitehaven, there are coal-mines, and the hematite of the Carboniferous Limestones has given rise to the active ironworks of Barrow-in-Furness, now the largest town in the district.