Advances in Earth Science
• Articles •
Shen Wenjie,Lin Yangting,Wang Daode,Zhou Yongzhang,Miao Bingkui. Advances in the Study of Natural Fullerenes with Special Discussion on P-T Boundary Fullerenes[J]. Advances in Earth Science, 2006, 21(9): 903-910.
Fullerene, the third carbon allotrope besides graphite and diamond, was discovered by Kroto et al. in 1985. Since then, the studies of fullerenes has become the worldwide hot topic and significant progresses in many fields have been achieved. The stable carbon cage structure of fullerene C60 indicates it should occur abundantly in circumstellar and interstellar media. For its special conditions of production, fullerene is hardly yielded through the process of the common earth environment and dynamic geology. The first presence of fullerene in Shungite, Russia in 1992 aroused the interest of studying natural fullerene. Since the discover of fullerene in meteorites and meteorite impact structure, the existences of fullerenes in event strata and its origins have come to the front of scientists. The P-T event boundary strata have been long time of the scientists' interests and puzzles because of the largest mass extinctions in the history of geology during Permian-Triassic boundary. In this paper, advances in the study of fullerenes in meteorites, impact structure, K-T boundary and P-T boundary are reviewed. The occurrence of fullerenes is discussed and it is pointed out that each step may effect the examination of fullerene from sample collection to test. Fullerenes have been detected in the different P-T boundary strata by many scientists and the origins of fullerenes were examined in depth. Fullerenes in the P-T boundary strata likely came from meteorite impact or natural fires and the noble gas isotopic composition in fullerene carbon cage can be used to discriminate them. The wide occurrences of fullerenes in the event strata suggest that fullerene can be one of the important geochemical indicators of strata events and fullerene with abnormal noble gas isotopic composition a direct indicator of extraterrestrial impact events.