Petrographic, Geochemical, Isotopic, and Noble Gas Characterization of NWA 8409

Stephant, A., Desch, S. J., Anand, M., Zhao, X., Cuppone, T., Rider-Stokes, B. G., Carli, C., Gamblin, J., Füri, E., Nottingham, M., Pratesi, G., & Franchi, I. A. (2026). Exploring nebular ingassing in the inner Solar System: evidence from the unique achondrite NWA 8409. Advances in Geochemistry and Cosmochemistry, 2(1), 764. https://doi.org/10.33063/agc.v2i1.764

This dataset presents the Petrographic, Geochemical, Isotopic, and Noble Gas Characterization of NWA 8409

1: NanoSIMS raw and treated data for H2O estimations and D/H ratio in pyroxenes of NWA 8409.

NanoSIMS raw and background-corrected data used for estimating H₂O concentrations and D/H ratios in pyroxenes from NWA 8409. Measurements were performed using a Cameca NanoSIMS 50L at The Open University. Reported values include secondary ion intensities (H⁻, D⁻, ¹⁶O⁻), calculated H₂O contents, δD values, associated uncertainties (2σ), and corrections applied for instrumental mass fractionation, analytical background, and cosmogenic spallation

2: Literature data for H2O and dD in NAMs of achondrites and bulk/ice of chondrites

compilation of literature H₂O contents and hydrogen isotopic compositions (δD) of nominally anhydrous minerals (NAMs) from achondrites, together with bulk and ice compositions of chondrites. No new analyses were performed for this table; data are reproduced from published sources to provide a comparative framework for evaluating the volatile inventory and isotopic signatures of NWA 8409 relative to other inner Solar System materials.

3: Bibliography of listed references from page 2

4: Noble gases

Noble gas abundances and isotopic ratios (Ne and Ar) measured in bulk fragments of NWA 8409 using a NoblesseHR noble gas mass spectrometer at the noble gas facility of the Centre de Recherches Pétrographiques et Géochimiques (CRPG, France), following CO₂ laser extraction. Data include isotopic ratios, elemental concentrations, blank corrections, and analytical uncertainties, and constrain cosmic-ray exposure effects.

5: ICPMS bulk and trace elements for NWA 8409 (this study) and paired meteorites (literature)

Bulk major and trace element compositions of NWA 8409 determined in this study by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) at the Department of Earth Sciences, University of Firenze, together with published data for paired samples from the literature. These data are used to assess geochemical variability, pairing relationships.

6: Mineralogy of NWA 8409

Modal mineralogy and mineral chemical compositions of NWA 8409 derived from scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS; ZEISS EVO MA 15), electron back-scatter diffraction (EBSD; Oxford Instruments Symmetry 2 detector), and focused ion beam–SEM (Zeiss Crossbeam 550). These observations document the textural context of the analyzed phases and underpin interpretations of petrogenesis and thermal history.