Ferromagnetic-superparamagnetic granulometry of lunar surface materialsA technique of magnetic granulometry is applied to previously reported data for the temperature dependence of isothermal remanent magnetization (IRM) in 13 lunar surface samples, including three soils. Observed increases in IRM with decreasing temperature are attributed to changes from superparamagnetic to single-domain types of behavior for fine metallic-iron particles. Based on this hypothesis, the temperature dependence of IRM in the examined samples is analyzed to obtain particle-size distributions over the range of mean diameters from 30 to 130 A. It is found that the distribution functions for the soils and a low-grade breccia vary as the inverse square of particle volume and that the distributions for recrystallized breccias and igneous rocks apparently peak about mean values.
Document ID
19770051845
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Schwerer, F. C. (United States Steel Corp. Monroeville, Pa., United States)
Nagata, T. (National Institute of Polar Research Tokyo, Japan)