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Fulgurites are a geological consequence of a lightning stroke to rocks. They are tubular or drop-shaped form composed of glass, relics of surrounding rocks and new mineral formations.
Two types of fulgurites are noted. They are determined by target rocks: clastofulgurites (aleuro- or psammito-) formed on different porous rocks, and petrofulgurites resulted from lightning discharge on exposed hard rocks. We have discovered a new type of fulgurites - phytofulgurites which formed on plants.
A lightning stroke to a dry haycock (village of Podvolok, Chita region, Russia; August 2002) resulted in grass inflamation and its partial coking in the lower part without air access. On the ground among ash a cake-like body was found which had rolled fibrous structure and size of 15 x 16 cm, 1 cm thick, its weight was about 90 g. It was presented by a complex hydrocarbon polymer C411H182N26S corresponding to natural medium anthraxolite, similar to oil coke. The following elements compose both fulgurites and inclusions captured from soil and new mineral phases: O, Si, Ca, Mg, Mn (about 1% and less), Fe, Ti, Al, Sr, K, P, Cu, Zn, Pb, Co (less than 1%). Isotopic ratio σ13C/12C -27,795 corresponds to earth plants. Determined phytofulgurite differs from other natural bitumen by extraordinary high content of amino acids (2.36 mg/g) with the predominance of L-modifications. Relic and new inclusions compose 10-15% of volume. Relic inclusions are presented by fossilized diatoms composed of silica. New inclusions are presented by silica, quartz, calcium-magnesium carbonates, sulphates, leaded brass.
The process of atmogenic electric discharge transformation of plants into bitumen is interesting not only scientifically, but also technologically.
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