The Sample Analysis at Mars (SAM) instrument on the Curiosity rover has detected evidence of oxychlorine compounds (i.e., perchlorates and chlorates) in Gale crater, which has implications for past habitability, diagenesis, aqueous processes, interpretation of in situ organic analyses, understanding the martian chlorine cycle, and hazards and resources for future human exploration. Pure oxychlorines and mixtures of oxychlorines with Mars-analog phases have been analyzed for their oxygen (O₂) and hydrogen chloride (HCl) releases on SAM laboratory analog instruments in order to constrain which phases are present in Gale crater. These studies demonstrated that oxychlorines evolve O₂ releases with peaks between ~200 and 600 °C, although the thermal decomposition temperatures and the amount of evolved O₂ decrease when iron phases are present in the sample. Mg and Fe oxychlorines decompose into oxides and release HCl between ~200 and 542 °C. Ca, Na, and K oxychlorines thermally decompose into chlorides and do not evolve HCl by themselves. However, the chlorides (original or from oxychlorine decomposition) can react with water-evolving phases (e.g., phyllosilicates) in the sample and evolve HCl within the temperature range of SAM (<~870 °C). These laboratory analog studies support that the SAM detection of oxychlorine phases is consistent with the presence of Mg, Ca, Na, and K perchlorate and/or chlorate along with possible contributions from adsorbed oxychlorines in Gale crater samples.

中文翻译：

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火星演化的气体分析实验室模拟工作中的样品分析综述，支持火星大风火山口中的高氯酸盐和氯酸盐

在“好奇号”漫游者上进行的火星样品分析（SAM）仪器检测到大风火山口中的氧化氯化合物（即高氯酸盐和氯酸盐）的证据，这对过去的可居住性，成岩作用，含水过程，原位有机分析解释，理解有影响。火星的氯气循环，以及对人类未来探索的危害和资源。为了限制Gale陨石坑中存在哪些相，已经分析了纯氧氯酸和具有Mars类似相的氧氯酸混合物的氧（O ₂）和氯化氢（HCl）释放量。这些研究表明，氯代氧可释放出O _2。当样品中存在铁相时，尽管热分解温度和释放出的O ₂量减少，但释放的峰在〜200至600°C之间。镁和铁的氯氧化物分解成氧化物，并在〜200至542°C之间释放HCl。Ca，Na和K的氧氯化物会热分解成氯化物，而不会自行生成HCl。但是，氯化物（原始的或氯氧根分解产生的）会与样品中的水相（例如页硅酸盐）发生反应，并在SAM（<〜870°C）的温度范围内释放出HCl。这些实验室模拟研究表明，SAM检测中的氯气相与Mg，Ca，Na和K高氯酸盐和/或氯酸盐的存在以及大风火山口样品中吸附的氯气的贡献相一致。