At one time I worked on 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.

This core log was completed in 1992 by M. Knoper and G. von Gruenewaldt, while at the Institute for Geological Research on the Bushveld Complex, University of Pretoria, South Africa. The research was supported by F.R.D. funding to G. von Gruenewaldt, and by funding awarded by the University of Pretoria to G. von Gruenewaldt and to M. Knoper. The core log was first published online in 1996; it may be cited as follows…

Knoper, M.W., and von Gruenewaldt, G., 1996, The Bellevue (BV-1) borehole core log: 2.9 km of Bushveld Complex stratigraphy (northern lobe), Potgietersrus, South Africa, Open file report (Institute for Geological Research on the Bushveld Complex, University of Pretoria)
DOI: 10.25131/ASYA3037

Note that mineral modes, rock names, and the igneous stratigraphy described in the core log were determined by examination of drill core specimens. Letters assigned to magnetitite layers have not been formalized and are provided as a means to informally reference the different magnetitite layers in this part of the northern Bushveld Complex. Depth in meters was measured (downwards) from the drillhole collar. The Bellevue BV-1 core is currently stored at the South African Council for Geoscience, National Core Library, Private Bag X112, Pretoria 0001, South Africa.

The following peer-reviewed research paper is based on core samples from BV-1…

Ashwal, L.D., Webb, S.J., and Knoper, M.W., 2005, Magmatic stratigraphy in the Bushveld Northern Lobe: continuous geophysical and mineralogical data from the 2950 m Bellevue drillcore, South African Journal of Geology, volume 108, pages 199-232
DOI: 10.2113/108.2.199