Testing for fullerenes in geologic materials: Oklo carbonaceous substances, Karelian Shungites, Sudb
The presence of low concentrations of fullerenes has been reported from numerous terrestrial and meteoritic sources (Buseck, 2002). In a recent paper, Mossman et al. (2003) present mass spectra of carbonaceous substances using laser desorption ionization (LDI) and high-resolution electron-impact mass spectrometry. The authors confirm the presence of fullerenes in the Onaping Formation, Black Tuff from Sudbury, Ontario, but do not find fullerenes in carbon-rich shungite rocks from the Lake Onega region of Karelia, Russia. They conclude that the earlier observation of fullerenes in Karelian shungite may have been due to the intrusion of basic igneous rocks and attribute the absence of fullerenes in the four shungite samples they studied to the possible heterogeneity of shungites. However, the authors also argue: “Alternative explanations include the possibility that fullerenes do not occur in shungite, or that the discovery of fullerenes in shungite may have been an artifact of the analyses” (Mossman et al., 2003, p. 257). Moreover, the authors conclude that natural fullerenes appear to form exclusively in extraterrestrial samples. We disagree with these conclusions.