The effect of high temperatures on the mid-to-far-infrared emission and near-infrared reflectance spectra of phyllosilicates and natural zeolites: Implications for martian exploration

Details The effect of high temperatures on the mid-to-far-infrared emission and near-infrared reflectance spectra of phyllosilicates and natural zeolites: Implications for martian exploration The effect of high temperatures on the mid-to-far-infrared emission and near-infrared reflectance spectra of phyllosilicates and natural zeolites: Implications for martian exploration

Mar 2012

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012icar..218..585c&link_type=abstract

Icarus, Volume 218, Issue 1, p. 585-601.

Computer Science

Scientific paper

Most phyllosilicates on Mars appear to be associated with ancient terrains. As such, they may have experienced shock heating produced by impacts and could have been significantly altered or melted. We characterized the effects of high temperatures on the mid-to-far-infrared (mid-to-far-IR) emission (100-1400 cm-1; 7.1-100 μm) and near-infrared (NIR) reflectance (1.2-2.5 μm) spectra of phyllosilicates by measuring experimentally calcined (100-900 °C) phyllosilicates and also two zeolites. Correlated differential scanning calorimetry (DSC) measurements were also performed on each sample to provide insight into the thermal activities of the phyllosilicates and natural zeolites. Our results indicate that all phyllosilicates exhibit characteristic degradations in both NIR and mid-to-far-IR spectral properties between 400 and 800 °C, mainly attributable to the dehydroxylation and recrystallization processes as temperature increases. Spectral features of natural zeolites persist to higher temperatures compared to features of phyllosilicates during heating treatments. The thermal behaviors of phyllosilicate infrared (IR) properties are greatly influenced by the compositions of the octahedral cations: (1) changes in both the NIR and mid-to-far-IR spectra of phyllosilicates tend to occur at lower temperatures (300-400 °C) in the Fe3+-rich samples as compared to the Al3+-rich types (400-600 °C); (2) Mg2+-trioctahedral phyllosilicates hectorite, saponite, and sepiolite all display major mid-to-far-IR spectral changes at 700 °C, corresponding to the formation of enstatite; (3) phyllosilicates that have minor replacement of Mg2+ for Al3+ in octahedral positions (e.g. cheto-type montmorillonite and palygorskite) show an absorption band at ˜920 cm-1 that becomes strong at 900 °C. Inconsistency between spectral behaviors in the mid-to-far-IR and NIR regions is also discussed for phyllosilicates. Results from this study have provided suggestive evidence for the scenario that some phyllosilicates could lose all original spectral features in mid-to-far-IR region while maintaining their characteristic hydration bands in NIR region in the same temperature range.

Affiliated with

Also associated with

No associations

Rating

The effect of high temperatures on the mid-to-far-infrared emission and near-infrared reflectance spectra of phyllosilicates and natural zeolites: Implications for martian exploration 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 The effect of high temperatures on the mid-to-far-infrared emission and near-infrared reflectance spectra of phyllosilicates and natural zeolites: Implications for martian exploration, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The effect of high temperatures on the mid-to-far-infrared emission and near-infrared reflectance spectra of phyllosilicates and natural zeolites: Implications for martian exploration will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1560757