Microwave resonance thermomagnetic analysis: A new method for characterizing fine-grained ferromagnetic constituents in lunar materials
Abstract
Microwave resonance thermomagnetic analysis (MRTA) is the name given to a newly evolved technique for inferring the natures of fine-grained ferromagnetic constituents in lunar materials. Based on standard ferromagnetic resonance (FMR) procedures, the method makes use of the microwave skin effect for diagnosing the presence of metallic iron. Modelling experiments carried out on well-characterized iron and magnetitelike precipitates produced independently in simulated lunar glasses, coupled with published data for magnetite, provide a potential basis for detecting and discriminating between iron metal and ferric iron spinel, even when both are present in an unknown sample. Application of the technique to the lunar samples indicates the possible existence of magnetitelike phases in amounts up to ~0.3 wt% in soils from seven sampled regions of the moon. These findings do not require any special geologic processes for their explanation, although some evidence supports the suggestion that fumarolic activity may have occurred in the lunar highlands.
- Publication:
-
Journal of Geophysical Research
- Pub Date:
- July 1975
- DOI:
- 10.1029/JB080i020p02935
- Bibcode:
- 1975JGR....80.2935G
- Keywords:
-
- Ferromagnetic Materials;
- Fines;
- Lunar Soil;
- Microwave Resonance;
- Thermomagnetic Effects;
- Glass;
- Iron;
- Lunar Rocks;
- Magnetite;
- Precipitates;
- Remanence