Details

Autor(en) / Beteiligte

• Feng, H.
• Jones, K. W.
• Tomov, S.
• Stewart, B.
• Herzog, G. F.
• Schnabel, C.
• Brownlee, D. E.

Titel

Internal structure of type I deep-sea spherules by X-ray computed microtomography

Ist Teil von

• Meteoritics & planetary science, 2005-02, Vol.40 (2), p.195-206

Ort / Verlag

Oxford, UK: Blackwell Publishing Ltd

Erscheinungsjahr

2005

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• — The internal structures of type I spherules (melted micrometeorites rich in iron) have been investigated using synchrotron‐based computed microtomography. Variations from sphericity are small—the average ratio of the largest to the smallest semimajor axis is 1.07 ± 0.06. The X‐ray tomographs reveal interior cavities, four spherules with metal cores with diameters ranging from 57 to 143 μm and, in two spherules, high attenuation features thought to be nuggets rich in platinumgroup elements. Bulk densities range from 4.2 to 5.9 g/cm3 and average grain densities from 4.5 to 6.5 (g/cm3) with uncertainties of 10–15%. The average grain densities are those expected for materials containing mostly oxides of iron and nickel. The tomographic density measurements indicate an average void space of 5+8‐5%. The void spaces may be contraction features or the skeletons of bubbles that formed in the molten precursors during atmospheric passage.