 Kidd is the deepest base metal mine in the world.The bottom of No.4 shaft at Kidd Creek Mine D is below the surface, below sea level, the deepest accessible non-marine point on earth.Hannington, M. D., and Barrie, C. T., editors, 1999, The Giant Kidd Creek Volcanogenic Massive Sulfide Deposit, Western Abitibi Subprovince, Canada