An impact origin for the foliation of chondrites

Meteoritics &Amp; Planetary Science

Chevrier

et al. 2005

Section: Methods and Sample Descriptionmentioning

confidence: 99%

Matching Martian crustal magnetization and magnetic properties of Martian meteorites

Meteoritics &Amp; Planetary Science

Chevrier

et al. 2005

“…This estimate of uncertainty does not take into account magnetic anisotropy effects (Gattacceca et al 2005), such as shape anisotropy, which can be large for log χ > 5. A conservative estimate of maximum uncertainty may therefore be ±40%, i.e., 0.15 log χ units.…”

Section: Sm30 Magnetic Susceptibility Measurementsmentioning

confidence: 99%

In situ identification, pairing, and classification of meteorites from Antarctica through magnetic susceptibility measurements

Folco

Meteorit & Planetary Scien

et al. 2006

In situ identification, pairing, and classification of meteorites from Antarctica through magnetic susceptibility measurements Abstract-We report on the effectiveness of using magnetic measurements in the search for meteorites on the Antarctic ice sheet, which is thus far the Earth's most productive terrain. Magnetic susceptibility measurements carried out with a pocket meter (SM30) during the 2003/04 PNRA meteorite collection expedition to northern Victoria Land (Antarctica) proved to be a rapid, sensitive, non-destructive means for the in situ identification, pairing, and classification of meteorites. In blue ice fields characterized by the presence of moraines and glacial drifts (e.g., Miller Butte, Roberts Butte, and Frontier Mountain), magnetic susceptibility measurements allowed discrimination of meteorites from abundant terrestrial stones that look like meteorites thanks to the relatively high magnetic susceptibility of the former with respect to terrestrial rocks. Comparative measurements helped identify 16 paired fragments found at Johannessen Nunataks, thereby reducing unnecessary duplication of laboratory analyses and statistical bias. Following classifications schemes developed by us in this and previous works, magnetic susceptibility measurements also helped classify stony meteorites directly in the field, thereby providing a means for selecting samples with higher research priority. A magnetic gradiometer capable of detecting perturbations in the Earth's magnetic field induced by the presence of meteorites was an efficient tool for locating meteorites buried in snow along the downwind margin of the Frontier Mountain blue ice field. Based on these results, we believe that magnetic sensors should constitute an additional payload for robotic search for meteorites on the Antarctic ice sheet and, by extension, on the surface of Mars where meteorite accumulations are predicted by theoretical works. Lastly, magnetic susceptibility data was successfully used to crosscheck the later petrographic classification of the 123 recovered meteorites, allowing the detection of misclassified or peculiar specimens.

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“…Saturation remanence (M rs ) was also compiled for chondrites to evaluate the range of likely remanent magnetization for asteroids with chondritic compositions. Besides being a classification tool and a first step in more sophisticated magnetic applications (paleomagnetism: see Gattacceca and Rochette [2004]; magnetic anisotropy: see Gattacceca et al [2005]; magnetic mineralogy: see Kohout et al [2007]), both parameters have applications for the exploration of the solar system (e.g., Pesonen et al 1993;Rochette et al 2004). Therefore the same parameters have been analyzed in the different achondritic groups: the primitive (i.e., undepleted in metal) achondrites-acapulcoite-lodranite clan, winonaite, ureilite and differentiated ones-angrite, aubrite, brachinite, HED (howardite-eucrite-diogenite clan), and Martian meteorites.…”

Section: Introductionmentioning

confidence: 99%

Magnetic classification of stony meteorites: 3. Achondrites

Meteorit & Planetary Scien

Bourot-Denise

et al. 2009