Figures for the Black Horse deposit, as of July 2015 -

"using this 20% cut-off, there are 85.9 million tonnes at a grade of 34.5% Cr2O3 of Inferred Resources."

This deposit reaches from approximately 350 meters below the surface down to 1,400 meters

In my opinion this deposit would give very similar returns when mined to those from the Big Daddy deposit. Might be amenable to an open pit for the nearest to surface mineralisation, at the start of mining operations.