Characterization of Antarctic micrometeorites by thermoluminescence

by Sedaghatpour, F.; Sears, D. W. G.

In order to explore the nature and history of micrometeorites, we have measured the thermoluminescence (TL) properties of four micrometeorites, three cosmic spherules, and one irregular scoriaceous particle, that we found in a survey of 17 micrometeorites. These micrometeorites have TL sensitivities ranging from 0.017 +/- 0.002 to 0.087 +/- 0.009 (on a scale normalized to 4 mg of the H3.9 chondrite Dhajala). The four micrometeorites have very similar TL peak temperatures and TL peak widths, and these distinguish them from CI, most CM, CV, CO, and ordinary chondrites. However, the TL properties of these rnicrometeorites closely resemble those of the unusual CM chondrite MacAlpine Hills (MAC) 87300 and terrestrial forsterites. Heating experiments on submillimeter chips of a CM chondrite and a H5 chondrite suggest that these TL properties are have not been significantly affected by atmospheric passage. Thus we suggest that there is no simple linkage between these micrometeorites and the established meteorite classes, and that forsterite is an important component of these microrneteorites, as it is in many primitive solar system materials.

Journal
Meteoritics and Planetary Science
Volume
44
Issue
5
Year
2009
Start Page
653-664
URL
https://dx.doi.org/10.1111/j.1945-5100.2009.tb00761.x
ISBN/ISSN
1945-5100; 1086-9379
DOI
10.1111/j.1945-5100.2009.tb00761.x