Some of the tridymite in the monomict Northwest Africa (NWA) 11591 eucrite are found to have sulfide‐rich replacement textures (SRTs) to varying degrees. The SRTs of tridymite in NWA 11591 are characterized by the distribution of loose porous regions with aggregates of quartz and minor troilite grains along the rims and fractures of the tridymite, and we propose a new mechanism for the origin of this texture. According to the volume and density conversion relationship, the quartz in the SRT of tridymite with a hackle fracture pattern was transformed from tridymite. We suggest that the primary tridymite grains are affected by the S‐rich vapors along the rims and fractures, leading to the transformation of tridymite into quartz. In addition, the S‐rich vapors reacted with Fe²⁺, which was transported from the relict tridymite and/or the adjacent Fe‐rich minerals, and/or the S‐rich vapors react with the exotic metallic Fe to form troilite grains. The sulfurization in NWA 11591 most likely occurred during the prolonged subsolidus thermal metamorphism in the shallow crust of Vesta and might be an open, relatively high temperature (>800 °C) process. Sulfur would be an important component of the metasomatic fluid on Vesta.

中文翻译：

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非洲西北部的单微生物尤金岩中的辉绿岩中记录的硫化作用11591

已发现西北部非洲独生生物（NWA）11591的辉绿岩中的某些具有不同程度的富含硫化物的置换纹理（SRT）。NWA 11591中的绿闪石的SRT的特征是，沿着绿闪石的边缘和断裂分布有疏松的多孔区域，聚集有石英和次要的三叶草晶粒，我们提出了这种纹理起源的新机制。根据体积和密度的转换关系，将具有闪闪断裂图案的鳞石英的SRT中的石英由鳞石英转化。我们建议主要的闪闪石晶粒受到沿边缘和断裂的富S蒸气的影响，从而导致闪闪石转变为石英。此外，富含S的蒸气与Fe ²⁺反应从残the石和/或邻近的富铁矿物中运出，和/或富S蒸气与奇特的金属铁反应形成三叶草晶粒。NWA 11591中的硫化极有可能发生在维斯塔浅层地壳长时间的亚固相热变质中，并且可能是一个开放的，相对较高的温度（> 800°C）过程。硫将成为维斯塔（Vesta）交代液的重要成分。