Illite Ilmenite

Figure 11. X-ray spectra of selected particles from Figure 10. Particles can be characterized in terms of their X-ray spectra. For example, high Si is indicative of quartz, whereas Al and Si suggest clays. In certain cases, the Si Al ratio can also distinguish between kaolinite and illite. Other components such as pyrite (Fe and S), rutile (Ti), ilmenite (Ti and Fe), and coke (C and S) can also be identified automatically by their characteristic X-rays.

The matrix of the till on Mt. Sirius is composed of quartz, plagioclase, K-feldspar, kaolinite, montmoril-lonite, and illite (Hagen 1988, p. 22). The sand-size fractions (1.0-0.0625 nun) contain heavy minerals including pyroxene, hornblende, garnet, tourmaline, rutile, zircon, apatite, sphene, magnetite, ilmenite, hematite, pyrite, and chalcopyrite. A bulk sample of the heavy mineral fraction of till on ML Sirius in Table 19.1 is composed primarily of iron, titanium, and manganese with lesser concentrations of chromium, zinc, copper, and nickel (Hagen 1988). Additional analyses of the heavy-mineral fractions of till in the Transantarctic Mountains were published by Faure et al. (1995). 

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