At one time I was attached to a research project that studied the drill core from a deep stratigraphic borehole drilled into the layered mafic/ultramafic rocks of the northern Bushveld Complex. Drilling to a depth of 2945.5 m was carried out over a period of ten months, and completed in late 1991. The core recovered from the drilling phase of the project represents a continuous record of magmatic stratigraphy, starting from the roof granites, through the Upper Zone, and ending about midway into the Main Zone. Continue reading →