Physics
Scientific paper
Dec 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agufm.p33b1442c&link_type=abstract
American Geophysical Union, Fall Meeting 2008, abstract #P33B-1442
Physics
5464 Remote Sensing
Scientific paper
The OMEGA visible and near infrared imaging spectrometer detected phyllosilicates in ancient Noachian terrains of Mars-an observation later confirmed by CRISM imaging spectrometer. Detailed mapping showed that the phyllosilicates, most of which are clay minerals, are found in ancient, heavily cratered terrains. These clay-bearing deposits contain interbedded and buried craters, and it is possible the clay minerals were repeatedly subjected to high temperatures resulting from impact processes. We hypothesize that the dehydration and dehydroxylation of clay minerals subjected to impact was a widespread process on early Mars, and that dehydrated and dehydroxylated clay minerals may be still abundant on the surface of Mars. The objective of this study is to characterize the infrared spectral features of clay minerals when they are heated to increasingly higher temperatures. Using a Nicolet 6700 FTIR spectrometer, we have acquired mid-infrared reflectance (500cm-1-7000cm-1), far-infrared reflectance (60cm-1-500cm-1) and ATR (attenuated total reflectance)(500cm-1-4000cm-1) spectra of 13 clay samples at different temperatures(from 100°C to 900°C). All of the clay samples have been prepared to be very pure (<2μm size fraction) and they were heated for 24 hours at each temperature. The structures of clay minerals are well known because of their typical layer structure and complex relations with water and OH bonds. Our data show that the infrared spectra of clay minerals changed as the temperature increased, which helps us to understand the temperature-related processes including removal of water and OH groups, change of Si-O bond, even the complete destruction of clay layer structures. Differences among dehydration and dehydroxylation conditions for these clay minerals are also discussed in this work. In our future work, we will continue to collect the infrared spectra of more clay minerals and collect additional data for our samples, including VNIR reflectance, XRD, NMR, and emissivity spectra, which can provide insights into the crystal structures and help us to answer the very first question: is it possible that dehydrated and dehydroxylated clay minerals are an explanation for poorly crystalline or amorphous materials on Mars?
Che Concong
Cintrón I.
Glotch Timothy
No associations
LandOfFree
The Infrared Spectra Study of Dehydrated and Dehydroxylated Clay Samples 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 Infrared Spectra Study of Dehydrated and Dehydroxylated Clay Samples, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Infrared Spectra Study of Dehydrated and Dehydroxylated Clay Samples will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1237814