Magnetic measurements of glass from Tikal, Guatemala: Possible tektites

• Published in: Journal of Geophysical Research 2000-08, Vol.105 (B8), p.18921-18925
• Main Authors: Senftle, F. E., Thorpe, A. N., Grant, J. R., Hildebrand, A., Moholy‐Nagy, H., Evans, B. J., May, L.
• Format: Article
• Language: English
• Subjects: Cosmochemistry. Extraterrestrial geology; Earth sciences; Earth, ocean, space; Exact sciences and technology; Geochemistry; Geophysics: general, magnetic, electric and thermic methods and properties; Internal geophysics; Meteorites. Tectites. Impactites; Soil and rock geochemistry
• ISSN: 0148-0227; 2156-2202
• DOI: 10.1029/2000JB900125

Certain glass nodules found at the archeological site at Tikal, Guatemala, have been considered as possible tektites. To test this possibility, magnetic studies have been made on three of the glass specimens. These specimens are similar to tektites, both visually and also because they contain very little Fe3+ as detected by Mössbauer spectroscopy. The magnetic Curie constants are similar in magnitude to those found for normal tektites but show some variation from point to point in the same specimen. This variation reflects an inhomogeneity in the iron concentration. The Fe2+ calculated from the Curie constants accounts for most of the iron. The temperature‐independent component of the total dc magnetic susceptibility is several times higher than that found in tektites from other strewn fields. The high values can be explained if the glass contains metallic iron spherules with Fe in the parts per million range and/or a ferromagnetic component which does not saturate in a low magnetic field. The magnetic properties resemble those of Muong Nong type tektites and suggest that the Tikal glass specimens are tektites of the Muong Nong type.