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Iain Gilmour
Geochemistry of carbon in terrestrial impact processes (in Meteorites; flux with time and impact effects)
Geological Society Special Publications (1998), 140 205-216
Abstract: Index Terms/Descriptors: GeoRef, Copyright 2004, American Geological Institute.
Terrestrial impact craters appear to be unique in the geological environment in that they contain evidence for the presence of all four carbon allotropes: graphite, diamond, C 60 and carbynes. This diversity appears to reflect the wide range of physical and chemical conditions that occur during impact processes including shock-induced alterations and vapour-phase chemistry. Impact-produced diamonds are known from several impact craters around the world, and their ability to survive over immense periods of geological time makes the presence of diamonds an important criterion for the identification of terrestrial impact structures.
C-13/C-12; carbon; Cenozoic; Cretaceous; diamond; geochemistry; graphite; impact craters; impact features; impacts; isotope ratios; isotopes; K-T boundary; lower Paleocene; Mesozoic; metamorphism; meteorites; mineral composition; native elements; Paleocene; Paleogene; SEM data; shock metamorphism; stable isotopes; stratigraphic boundary; TEM data; Tertiary; Upper Cretaceous; X-ray diffraction data