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Glassy Microspherules from Bomb Combustion of Charcoal

Published online by Cambridge University Press:  18 July 2016

Richard Burleigh  and
Nigel Meeks
Richard Burleigh
Affiliation:
Research Laboratory, The British Museum, London WC1B 3DG, England
Nigel Meeks
Affiliation:
Research Laboratory, The British Museum, London WC1B 3DG, England
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Glassy microspherules, typically 200μm or less in diameter, are well documented from a variety of terrestrial and extraterrestrial sources (Baker, 1959, p 192–198; Glass, 1969; Rost, 1969; McKay, Greenwood & Morrison, 1970; Mueller & Hinsch, 1970; Cross, 1971; O'Keefe, 1980). To these we would add the formation of microspherules of similar habit when wood charcoal is burned in a combustion bomb (Barker, Burleigh & Meeks, 1969; Burleigh, 1973, 1974; Switsur, 1973; Switsur et al, 1974) as a first step in the chemical synthesis of samples for 14C age measurement. The glassy material of these spherules originates from fusion at the high temperatures reached during the combustion, of traces of alkali-metal minerals in the charcoal and silica bodies (phytoliths) within its microstructure. Other materials commonly burned, such as bone collagen, do not yield microspherules. The age and source of the charcoal are immaterial, though different species (and perhaps other woody plant materials) may be more-or-less productive of spherules. Here we give a brief summary of the characteristics of these glassy microspherules, based on optical and scanning electron microscopy and energy-dispersive x-ray analysis.

Type
Notes and Comments
Information
Radiocarbon , Volume 28 , Issue 1 , 1986 , pp. 165 - 166
Copyright
Copyright © The American Journal of Science 

References

Baker, G, 1959, Tektites: Natl Mus Victoria Mem, no. 23 (Melbourne).CrossRefGoogle Scholar
Barker, H, Burleigh, R and Meeks, N, 1969, New method for the combustion of samples for radiocarbon dating: Nature, v 221, p 49–50.CrossRefGoogle Scholar
Bodsworth, C, 1963, Physical chemistry of iron and steel manufacture: London, Longmans.Google Scholar
Bottinga, Y and Weill, D, 1972, The viscosity of magmatic silicate liquids—a model for calculation: Am Jour Sci, v 272, p 442–443.CrossRefGoogle Scholar
Burleigh, R, 1973, Bomb combustion of radiocarbon samples, in Rafter, T A and Grant-Taylor, T, eds, Internatl conf on radiocarbon dating, 8th, Proc: Wellington, New Zealand, Royal Soc New Zealand, v 1, p 110–119.Google Scholar
Burleigh, R, 1974, A bomb method for rapid combustion of samples, in Crook, M A and Johnson, P, eds, Liquid scintillation counting, v 3, p 295–302: London, Heyden.Google Scholar
Cross, C A, 1971, Formation of glass spheres on the moon: Nature, v 233, p 185–186.CrossRefGoogle ScholarPubMed
Glass, B P, 1969, Silicate spherules from Tunguska impact area—electron microprobe analysis: Science, v 164, p 547–549.CrossRefGoogle ScholarPubMed
McKay, D S, Greenwood, W R and Morrison, D A, 1970, Morphology and related chemistry of small lunar particles from Tranquility Base: Science, v 167, p 654–656.CrossRefGoogle ScholarPubMed
Muan, A and Osborn, E F, 1965, Phase equilibria among oxides in steelmaking: Oxford, Pergamon.Google Scholar
Mueller, G and Hinsch, G W, 1970, Glassy particles in lunar fines: Nature, v 228, p 254–258.CrossRefGoogle ScholarPubMed
O'Keefe, J A, 1980, The terminal Eocene event—formation of a ring system around the Earth?: Nature, v 285, p 309–311.CrossRefGoogle Scholar
Rost, R, 1969, Sculpturing of moldavites and the problem of micromoldavites: Jour Geophys Research, v 74, p 6816–6824.CrossRefGoogle Scholar
Switsur, V R, 1973, Combustion bombs for radiocarbon dating, in Rafter, T A and Grant-Taylor, T, eds, Internatl conf on radiocarbon dating, 8th, Proc: Wellington, New Zealand, Royal Soc New Zealand, v 1, p 120–132.Google Scholar
Switsur, V R, Burleigh, R, Meeks, N and Cleland, J M, 1974, A new sample combustion bomb for radiocarbon dating: Internatl Jour Applied Radiation and Isotopes, v 25, p 113–117.Google Scholar
Wheeler, E L, 1958, Scientific glassblowing: New York, Interscience.Google Scholar