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
Dual screen wallpaper of Twin Peaks on Mars
Recently I made dual screen wallpaper from one of the Mars Pathfinder panoramas taken using the IMP at the Sagan Memorial Station (i.e., the landing site). Some of the colorful names given to rocks in the panaroma include Yogi, Wedge, Grommit, Hippo, Flattop, Shark, Half Dome, Flute Top, Chimp, Stimpy, and Bookshelf – all in the Rock Garden. The wallpaper is ideally sized for a dual 1280×1024 display setup. Continue reading
Facies of the Merensky Reef
Mention reef facies to most geologists and they might conjure up a mental image of a carbonate reef complex. But to geologists working in the Bushveld Complex, reef facies is a descriptive term used to account for the variation a single mineralized horizon exhibits within the layered ultramafic-mafic sequence. One such horizon is that of the Merensky Reef, which has been laterally subdivided into different facies based on modal characteristics and textural appearance of the reef itself. The inherent complexities of these reef facies are revealed by detailed logging of numerous diamond drill cores through stratigraphic intervals. Continue reading
Steenkampskraal Thorium Mine
What follows is a description of the early mining history of the Mesoproterozoic-age Steenkampskraal monazite ore body located in southern Namaqualand, about 340 km north of Cape Town in South Africa. Steenkampskraal is a massive-lode ore body, possibly originating by igneous processes from an immiscible phosphate-sulphide-oxide magmatic liquid. The monazite ore occurs in a thin lenticular-shaped body surrounded by Mesoproterozoic granitic gneiss country rocks. The ore body is about 400 m in strike-length, extending about 450 m down-dip, with an average thickness of about 0.5 m. Continue reading
Annandagstoppane Nunataks
Out of the far western icefield of Western Dronning Maud Land (WDML) rise the Annandagstoppane nunataks. The name originates from the Norweigian word for the day after Christmas (i.e., Boxing Day) when these nunataks were first discovered. Continue reading