This Column was mapped at the south west end of Black Mesa because Proterozoic basement was exposed. No mapping has ever been done here before. The basement is schist, and a highly altered lava flow. The foliated Proterozoic rocks have the standard regional N.E. strike (between 9 to 25deg, grid north) and are tilted from vertical by  ~10 to 35 degrees, to the N.E. This column can be used as a general reference for the area.

• The basal conglomerate layer is iron stained, cross bedded in some places and cut with both vertical & horizontal calcite veins.
• There is a Nonconformity, representing ~1.7 Ga of missing time, between the Proterozoic basement and the Tertiary rocks above. Proterozoic rock fragments have been found in all sedimentary layers of Column1.