The Clear Hills iron deposit is an oolitic iron-rich facies of the Bad Heart Sandstone of Late Cretaceous age. The deposit crops put on the southern and northeastern flanks of the Clear Hills in northwestern Alberta, is essentially flat-lying and extends back from outcrop to underlie a large area of hills.
Lithologically, the deposit consists of dark brown and green to black, ferruginous colite, forming a bed up to 10 m thick. The ore bed is thickest in the northeast (Swift Creek) segment of the deposit, thinning westward to zero as the oolitic facies passes into siltstone and argillaceous sandstone. It is overlain and underlain by gray marine shales of the upper and lower Smoky Group.
The deposit has been known to exist for more than 50 years and has received considerable exploratory attention. Substantial reserves are proven, but low grade (35 percent Fe) and complex ore mineralogy have prevented development to date.
Hamilton, W.N. (1980): Clear Hills iron deposit: geology, mineralogy and ore reserves; Alberta Research Council, ARC/AGS Open File Report 1982-13, 51 p.