Ann: Tabac Cobalt Project - Investor Presentation-DLE.AX, page-140

Three minute rule caught up with me about possible pit design. Pretty much as you describe, including caveats, G.

Probably similar to Tropicana and other shallow dipping deposits that come close to surface. The bottom of the ore becomes the shallow footwall of the pit and ramps can snake down rather than circle a semi circular pit. The deeper the mine the more material has to mined off the top/high wall (extreme strip ratio) until it becomes sub economic. Then it is a matter of whether underground mining can be economic.

At Tabac, if the grades and continuity are there, bulk underground mining would likely come into play. Maybe longwall or other methods as in my recent post.

Below is a sectional cartoon view of what might be possible from a non mining engineers viewpoint. DYOR.