Geochemistry Investigation of Basaltic Rock for Developing the First Thailand Mars Simulant (TMS-01)

Terrestrial materials can be used to manufacture Mars simulants, which have chemical and geotechnical properties similar to Martian soil. Mars simulants are essential resources for research in Mars exploration programs. Volcanic rocks from the Loei-Phetchabun and Sa Kaeo volcanic belts in Thailand are widely distributed and suitable for developing a Thailand Mars Simulant (TMS-01) based on the raw materials of volcanic rocks from Lopburi, Phetchabun, Chanthaburi, and Trat provinces. In the current study, these samples were mechanically crushed using a Los Angeles abrasion machine, jaw crusher, and disc mill. The sample properties, including chemical and mineralogical composition, were analyzed using polarized light microscopy, X-ray diffraction, and X-ray fluorescence. X-ray absorption spectroscopy (XAS) was used to focus on the Fe K -edge X-ray absorption near-edge structure spectra of iron oxide minerals in the volcanic rocks. Compared to Martian soil, these volcanic rocks have higher SiO ₂ , Al ₂ O ₃ , and TiO ₂ , and lower FeO _t . They also have lower FeO _t compared to other Mars simulants. Some volcanic rocks have a higher MgO content than JSC Mars-1, while others contain less MgO than MGS-1. The mineral composition of these volcanic rocks mainly consists of plagioclase, pyroxene, and olivine, which is comparable to the Mojave Mars Stimulant. The XAS results indicated that the Fe in these volcanic rocks has an oxidation state between ferrous (Fe ²⁺ ) and ferric (Fe ³⁺ ) ions. Thus, basaltic rocks from Sa Kaeo province are potential raw materials for developing TMS-01. The process of its production is comparable to the physical weathering processes on Mars. The addition of iron oxide minerals should improve the chemical properties. For mass production, additional basaltic rocks were sourced from a mine in Nakhon Ratchasima province. Iron oxide minerals, including magnetite and hematite, along with gypsum, were added to Nakhon Ratchasima basaltic rocks at a 5 wt.% ratio of iron oxide to rock samples in two different recipes. This will allow the manufacturing of three raw materials for TMS-01. Further study on the physical and geotechnical properties is recommended to advance the development of TMS-01.