Skip to main content Accessibility help
×
Home

Glassy Microspherules from Bomb Combustion of Charcoal

  • Richard Burleigh (a1) and Nigel Meeks (a1)

Extract

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.

    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Glassy Microspherules from Bomb Combustion of Charcoal
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Glassy Microspherules from Bomb Combustion of Charcoal
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Glassy Microspherules from Bomb Combustion of Charcoal
      Available formats
      ×

Copyright

References

Hide All
Baker, G, 1959, Tektites: Natl Mus Victoria Mem, no. 23 (Melbourne).
Barker, H, Burleigh, R and Meeks, N, 1969, New method for the combustion of samples for radiocarbon dating: Nature, v 221, p 4950.
Bodsworth, C, 1963, Physical chemistry of iron and steel manufacture: London, Longmans.
Bottinga, Y and Weill, D, 1972, The viscosity of magmatic silicate liquids—a model for calculation: Am Jour Sci, v 272, p 442443.
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 110119.
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 295302: London, Heyden.
Cross, C A, 1971, Formation of glass spheres on the moon: Nature, v 233, p 185186.
Glass, B P, 1969, Silicate spherules from Tunguska impact area—electron microprobe analysis: Science, v 164, p 547549.
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 654656.
Muan, A and Osborn, E F, 1965, Phase equilibria among oxides in steelmaking: Oxford, Pergamon.
Mueller, G and Hinsch, G W, 1970, Glassy particles in lunar fines: Nature, v 228, p 254258.
O'Keefe, J A, 1980, The terminal Eocene event—formation of a ring system around the Earth?: Nature, v 285, p 309311.
Rost, R, 1969, Sculpturing of moldavites and the problem of micromoldavites: Jour Geophys Research, v 74, p 68166824.
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 120132.
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 113117.
Wheeler, E L, 1958, Scientific glassblowing: New York, Interscience.

Glassy Microspherules from Bomb Combustion of Charcoal

  • Richard Burleigh (a1) and Nigel Meeks (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed