Northwest Africa (NWA) 2737, one of the only three discovered Martian chassignites, provides critical constraints on the evolution of the Martian mantle and crust. Because of chassignites’ cumulative nature, they contain abundant melt inclusions (MI). MI are small droplets of melts trapped by crystals during the cooling of magma. They are critical to the study of pre-eruptive parental magma compositions, and thus, provide snapshots of the composition and evolution of Martian magmatic systems. Here, we present fractional crystallization models using parental magma composition calculated from NWA 2737 melt inclusions as starting compositions. We used the thermodynamic modeling software MELTS to model fractional crystallization of NWA 2737 parental magma compositions with a wide range of parameters (pressure, water content, oxygen fugacity). Our models show that the felsic compositions recently analyzed at the Martian surface in Gale crater, especially Sparkle and Angmaat, the two rocks thought to be analogous to the earliest continental crust on Earth, can be obtained by fractional crystallization of chassignite-like parental melts. Our results suggest a link between the processes that resulted in chassignites and the rocks analyzed in situ at Gale crater. To assess the possible scenarios for Martian magma migration and storage processes, we compared chassignites to terrestrial analogs formed via various mechanisms and proposed two mechanisms that may explain the intrusive and effusive rocks found in situ at Gale crater: (1) emplacement and fractionation in a closed-system crustal reservoir and (2) eruption of mafic to intermediate lavas of a relatively open system subject to constant replenishment.

中文翻译：

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chassignite NWA 2737 中的熔化包裹体：火星陨石和盖尔陨石坑岩石中记录的过程之间的联系

西北非洲 (NWA) 2737 是仅有的三个已发现的火星 chassignite 之一，为火星地幔和地壳的演化提供了关键限制。由于 chassignites 的累积性质，它们包含丰富的熔体包裹体 (MI)。MI 是在岩浆冷却过程中被晶体捕获的小熔体液滴。它们对于研究喷发前母体岩浆成分至关重要，因此提供了火星岩浆系统组成和演化的快照。在这里，我们使用从 NWA 2737 熔体包裹体计算的母岩浆成分作为起始成分提出了分级结晶模型。我们使用热力学建模软件 MELTS 对 NWA 2737 母岩浆成分的分级结晶进行建模，其参数范围很广（压力、水含量、氧逸度）。我们的模型表明，最近在盖尔陨石坑的火星表面分析的长英质成分，尤其是 Sparkle 和 Angmaat，这两种被认为类似于地球上最早的大陆地壳的岩石，可以通过类辉绿岩母体熔体的分步结晶获得。我们的结果表明，导致辉绿岩的形成过程与在盖尔陨石坑原位分析的岩石之间存在联系。为了评估火星岩浆迁移和储存过程的可能情景，我们将菱镁矿与通过各种机制形成的陆地类似物进行了比较，并提出了两种可能解释在盖尔陨石坑原位发现的侵入性和喷发性岩石的机制：