Lunar Meteorites as Key Geochemical Archives: Insights from Raman Spectroscopy and Comparative Planetary Analysis

LUNAR METEORITES AS KEY GEOCHEMICAL ARCHIVES: INSIGHTS FROM RAMAN SPECTROSCOPY AND COMPARATIVE PLANETARY ANALYSIS. M. Kaliwoda1,2, J. Zuncke2, I Drozdovsky3 and F. Joseph2. 1 Mineralogical State Collection Munich, Bavarian National History Collections, Theresienstrasse 41, 80333 Munich (kali[email protected]e). 2 LMU, Ludwig Maximilians University, Department of earth and environmental sciences, Theresienstrasse 41, 0333 Munich (Melanie.Kaliwod[email protected]muenchen.de, [email protected], j[email protected]mu.de) 8 3 European Space Agency (ESA), HRE-OT, Linder Höhe, D-51147 Cologne, Germany (Igor.Dro[email protected]t). Lunar meteorites serve as an essential source of information for understanding the geochemical structure and evolutionary history of the Moon. By analyzing these meteorites, we gain insights into the Moon’s geological and thermal evolution, including key processes such as volcanic activity, impact events, and differentiation. Each type of lunar meteorite provides a unique snapshot of different periods in the Moon’s history, offering a more comprehensive perspective [1, 2, 3, 4]. such as mantle xenoliths or ophiolitic mantle rocks, to gain further insights into planetary differentiation and magmatic evolution. Overall, lunar meteorites can provide a far more diverse and representative sample set than the Apollo landing sites alone, as they originate from various locations across the Moon’s surface. Their study not only enhances our knowledge about the moon and other terrestrial objects it contributes significantly to the advancement of Raman databases [7]. These databases are important for planetary science, as they facilitate the interpretation of spectroscopic data obtained from future robotic and human space missions. chemistry, history, and heterogeneity but also contributes significantly to the advancement of Raman spectral databases. These databases are crucial for planetary science, as they facilitate the interpretation of spectroscopic data obtained from robotic and human space missions. Ultimately, such research plays a pivotal role in the preparation of future lunar exploration endeavors and the development of spectroscopic methodologies for extraterrestrial applications. Figure 1: SEM investigation of Moon meteorite Bechar 003, feldspathic breccia. The same positions were analyzed with SEM and Raman spectroscopy. A crucial step in studying lunar meteorites is the detailed investigation of individual mineral phases. Key questions include: What is their growth history? Are they homogeneously structured or zoned in relation to specific element groups? Do they contain fluid inclusions, and if so, what is their composition? Furthermore, it is essential to determine whether these meteorites have been overprinted by melts, fluids, or subsequent impact events. To address these questions, the meteorites are initially analyzed using Raman spectroscopy [5, 6]. Subsequently, the same mineralogical spots are examined using electron microprobe analysis and scanning electron microscopy (SEM) to obtain high-resolution compositional data (Figure 1). The Mineralogical State Collection Munich (MSM) operates its own Raman spectroscopy laboratory and has developed an extensive mineral database, the MSM-MRD, which is continuously expanded and refined [7]. This database is a valuable tool for the classification and characterization of extraterrestrial materials, serving as a reference for both laboratory-based and in-situ spectroscopic analyses in planetary exploration missions. Lunar meteorites, in particular, contribute significantly to the development of Raman spectral libraries, which are essential for future space missions utilizing spectroscopic techniques for remote sensing and in-situ mineralogical investigations. [1] Joy KH et al. (2023) Reviews in Mineralogy and Geochemistr, 89 (1), 509–562 https://doi.org/10.2138/rmg.2023.89.12 [2] Anders E et al. (1973) the moon, 8, 3-24 https://doi.org/10.1007/BF00562747. [3] Warren PH (2005) Meteoritics & Planetary Science 40, Nr 3, 477–506. [4] Gnos E et al. Science, 305, 5684, 657-659. [5] Kaliwoda M et al. (2012) Spectroscopy letters, 46, 141-146. [6] Cao H et al. (2019) J of Raman Spec. https:// doi.org.10.1002/jrs.5727 [7] Drozdovsky I et al. (2020) data in brief, ……https://doi.org/10.1016/j.dib.2020.105985 Our research extends to other extraterrestrial bodies, including meteorites from Mars, Vesta, pallasites, and various types of chondrites. By analyzing these samples, we aim to enhance our understanding of planetary formation processes and the compositional diversity of solar system materials. In a subsequent step, we compare these extraterrestrial data with terrestrial analogs,