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Engineering topics

Dunn, J. R.

Publications and source records attributed to Dunn, J. R..

Magnetic effects of shock and their implications for lunar magnetism. II

Synthetic breccias were produced by hypervelocity impact of projectiles on basalt powders in order to study the magnetization acquired during shock lithification of soil. It was found that some of the lithified products record the field at the point where they land, while others carry the original primary remanence. Even those rocks recording the direction of the ambient field did not always faithfully record the intensity of the field. When rocks were exposed to shock, it was found that the magnetic hardness of a rock has a profound effect on its magnetic response. Shock effects are seen at shock levels of less than 10 kbar, which suggests that lunar samples may have been shock-demagnetized.

Cisowski, S. M.↗

Impact processes and lunar magnetism

Progress reports are presented of work related to the magnetic characterization of lunar samples, taking into account total iron ratios, questions of hysteresis classification, aspects of normalized remanence to remanent coercivity plots, and a comparison of NRM of lunar samples with hysteresis characterization. Shock experiments on lunar soil are also considered, giving attention to the effect of shock on the magnetic characteristics of lunar soil and the acquisition of remanence during shock. Preliminary measurements of individual soil particles and of samples from the Lunar Crater are discussed.

Cisowski, C. S.↗