| Abstrakt: |
Precisely constraining the shock pressure of a Mars sample is critical for revealing the shock condition, geological process, and habitability of the Martian surface. The crystal structure of plagioclase is sensitive to the moderate shock pressure, such that its infrared spectra may record the shock state of Martian materials. In this study, we present a new way for quantifying the shock pressure via the micro‐FTIR spectra of plagioclase by re‐analyzing the published spectra of experimental shocked feldspars. Using the absorption area of micro‐FTIR in the range of ∼1,000–1,150 cm−1, the shock pressures of plagioclases from three types of Mars meteorites were constrained. The results show that the nakhlite Northwest Africa (NWA) 10645, shergottite Tindouf 002, and martian breccia NWA 11220 have the shock pressure of 18.5 ± 5.2 GPa, >30 GPa, and 0–24.2 GPa, respectively. Our work demonstrates that the micro‐FTIR spectra of plagioclase is not only a quantitative tool for constraining the moderate shock pressure (<30 GPa) of Martian materials but also a useful technique for recognizing the high‐pressure phase maskelynite from plagioclase‐glass and evaluating the shock effects of Mars samples. In the future, this method will be available for the analysis of Mars samples returned by China's Tianwen‐3 mission in around 2030. Plain Language Summary: Tianwen‐3 mission is planned to return Mars samples to the Earth in around 2030. Revealing the shock features (e.g., shock pressure) of these Martian materials is critical for understanding the impact process, shock environment, and habitability on Mars. By re‐analyzing the published micro‐FTIR spectra of experimental shocked feldspars, a new method for quantifying the shock pressure of Mars samples has been represented. Then, the shock pressures of three Martian meteorites (nakhlite meteorite NWA 10645, shergottite meteorite Tindouf 002, and breccia meteorite NWA 11220) were constrained (i.e., 18.5 ± 5.2 GPa, >30 GPa, and 0–24.2 GPa, respectively). Our results demonstrate that the micro‐FTIR is a quantitative tool for constraining the moderate shock pressure (<30 GPa) of Martian materials. This method will provide us with a fast, low‐cost, and non‐destructive analytical approach to reveal the shock conditioning of Martian samples and other planetary materials. Key Points: A way was presented for constraining the shock pressure of the Mars sample via the micro‐FTIR spectra of plagioclaseNorthwest Africa (NWA) 10645, Tindouf 002, and NWA 11220 have the shock pressure of 18.5 ± 5.2 GPa, >30 GPa, and 0–24.2 GPa, respectivelyThis method is available for the analysis of Mars samples returned by Tianwen‐3 mission in around 2030 [ABSTRACT FROM AUTHOR] |
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