Organic and mineralogic heterogeneity of the Paris meteorite followed by FTIR hyperspectral imaging

1Z. Dionnet,1A. Aleon‐Toppani,1D. Baklouti,2F. Borondics,3F. Brisset,1Z. Djouadi,2C. Sandt,1R. Brunetto
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13178]
1Institut d’Astrophysique Spatiale, CNRS, Université Paris‐Sud, Université Paris‐Saclay, Orsay Cedex, France
2Synchrotron SOLEIL, l’Orme des Merisiers, Saint‐Aubin, France
3Institut de Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, Université Paris‐Saclay, Orsay Cedex, France
Published by arrangement with John Wiley & Sons

Significant compositional and structural heterogeneity at nm to mm scales is an important characteristic of primitive extraterrestrial materials. Here, we report the analysis of high‐resolution Fourier transform IR hyperspectral imaging analytical measurements at the micron scale on a fragment of the Paris carbonaceous chondrite, supported by Raman and SEM‐EDS measurements. The fragment is crushed in a diamond compression cell. The micro‐FTIR analyses are performed in transmission with two setups, an imaging microscope with a matrix detector using a thermal source and a system using a single point detector coupled with the synchrotron source at the SOLEIL synchrotron facility. We obtain the spatial distribution of chemical/mineralogical components. We confirm at a larger scale (10 μm) the presence of hydrated amorphous silicates observed at a smaller scale (1 μm). Based on the relative abundance of different minerals (hydrated amorphous silicate, olivine, diopside, and serpentine), we propose a sequence of aqueous alteration. Considering the spatial correlation of minerals with organic matter, we discuss the effects of aqueous alteration on the organic matter in bulk. In particular, we detect an increase in the CH2/CH3 ratio in the altered zone and present the possible scenarios that led to the observed chain length shortening/cracking of hydrocarbons.

Discuss

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s