Magnetic changes accompanying the thermal decomposition of nontronite /in air/ and its relevance to Martian mineralogy

Details Magnetic changes accompanying the thermal decomposition of nontronite /in air/ and its relevance to Martian mineralogy Magnetic changes accompanying the thermal decomposition of nontronite /in air/ and its relevance to Martian mineralogy

Nov 1982

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1982jgr....8710115m&link_type=abstract

(International Colloquium on Mars, 3rd: Dedicated to Thomas A. Mutch /1931-1980/, Pasadena, CA, Aug. 30-Sept. 2, 1982.) Journal

Physics

24

Heat Treatment, Magnetization, Mars Surface, Mineralogy, Planetary Composition, Thermal Decomposition, Chemical Composition, Crystal Lattices, Grain Boundaries, Hypervelocity Impact, Iron, Magnetic Measurement, Magnetic Properties, Microstructure, Phase Transformations, Temperature Effects

Scientific paper

It is found that the thermal treatment of nontronite in air, for long periods at 700 C or short periods at 900 C, results in the destruction of the nontronite structure, a distinct reddening in color, and a large increase in magnetic susceptibility and saturation magnetization. Measurements and calculations of the magnetic properties suggest that the magnetism is due to the presence of ultrafine particles of alpha or gamma Fe2O3. The highly magnetic thermally treated nontronite is amorphous to X-rays consistent with an ultrafine grain size. Prolonged heating results in the growth of alpha Fe2O3, while reflectivity spectra of a sample heated for 1 hr at 900 C indicate the presence of an opaque, magnetite-like phase in addition to alpha Fe2O3. It is found that the thermally treated nontronite has chemical, color, and magnetic properties similar to those found by Viking on Mars. It is concluded that these results indicate an origin for the fine grained Martian surface material by repeated impacts into an Fe-rich smectite-charged regolith (Weldon et al., 1980).

Affiliated with

Also associated with

No associations

Rating

Magnetic changes accompanying the thermal decomposition of nontronite /in air/ and its relevance to Martian mineralogy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Magnetic changes accompanying the thermal decomposition of nontronite /in air/ and its relevance to Martian mineralogy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic changes accompanying the thermal decomposition of nontronite /in air/ and its relevance to Martian mineralogy will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1758123