Northam Mine is located in the northwestern Bushveld Complex and is the deepest of the Pt. mines.  The 2.0 Ga Bushveld Complex is one of the largest mafic-ultramafic intrusives in the world and is comprised of over 5 kilometers of ultramafic pyroxenite and dunite, anorthosite and noritic gabbros.  Like the west Wits line, dykes of the 1.4 Ga Pilansberg complex cut thru the Bushveld.  Along these dykes water migrates downward from the surface.  The geothermal gradient is much higher here than in the Wits basin, attaining temperatures of 70^oC at 2.0 kmbls. To date, only two water samples have been collected and only the latter sample was a complete water-biological sample.  This water is from the relatively fresh water intersections.  Highly saline, gaseous water pockets do exist along mined horizons, especially in the ultramafic strata.

The two water samples were collected on opposite sides of the mines, one at level 7 near the Little John Dyke and the other near level 8.  The mine currently has 12 levels.