Multiscale correlated analysis of the Aguas Zarcas CM chondrite

Zélia Dionnet (1) , Alice Aléon-Toppani (1) , Rosario Brunetto (1) , Stefano Rubino (1) , Martin D. Suttle , Cateline Lantz (1) , Chrysa Avdellidou (2) , Donia Baklouti (1) , Ferenc Borondics , Zahia Djouadi (1) , Francesco Grieco , Eva Héripré (3) , Tomoki Nakamura , Alessandra Rotundi , Mario Scheel

1 IAS - Institut d'astrophysique spatiale
2 LAGRANGE - Joseph Louis LAGRANGE
3 UPCité - Université Paris Cité

In this paper, we report the results of a campaign of measurements on four fragments of the CM Aguas Zarcas (AZ) meteorite, combining X-ray computed tomography analysis and Fourier-transform infrared (FT-IR) spectroscopy. We estimated a petrologic type for our sampled CM lithology using the two independent techniques, and obtained a type CM2.5, in agreement with previous estimations. By comparing the Si-O 10-µm signature of the AZ average FT-IR spectra with other well-studied CMs, we place AZ in the context of aqueous alteration of CM parent bodies. Morphological characterization reveals that AZ has heterogeneous distribution of pores and a global porosity of 4.5 ± 0.5 vol%. We show that chondrules have a porosity of 6.3 ± 1 vol%. This larger porosity could be inherited due to various processes such as temperature variation during the chondrule formation and shocks or dissolution during aqueous alteration. Finally, we observed a correlation between 3D distributions of organic matter and mineral at micrometric scales, revealing a link between the abundance of organic matter and the presence of hydrated minerals. This supports the idea that aqueous alteration in AZ's parent body played a major role in the evolution of the organic matter.

Domaines: Planète et Univers [physics]

Zélia Dionnet, Alice Aléon-Toppani, Rosario Brunetto, Stefano Rubino, Martin D. Suttle, et al.. Multiscale correlated analysis of the Aguas Zarcas CM chondrite. Meteoritics and Planetary Science, 2022, 57, pp.965-988. ⟨10.1111/maps.13807⟩. ⟨insu-03744499⟩